| Message ID | 20191119151818.67531-3-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915 / LPSS / mfd: Select correct PWM controller to use based on VBT | expand |
On Tue, 19 Nov 2019, Hans de Goede wrote: > At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 > different PWM controllers for controlling the LCD's backlight brightness. > > Either the one integrated into the PMIC or the one integrated into the > SoC (the 1st LPSS PWM controller). > > So far in the LPSS code on BYT we have skipped registering the LPSS PWM > controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is > present, assuming that in this case the PMIC PWM controller will be used. > > On CHT we have been relying on only 1 of the 2 PWM controllers being > enabled in the DSDT at the same time; and always registered the lookup. > > So far this has been working, but the correct way to determine which PWM > controller needs to be used is by checking a bit in the VBT table and > recently I've learned about 2 different BYT devices: > Point of View MOBII TAB-P800W > Acer Switch 10 SW5-012 > > Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS > PWM controller (and the VBT correctly indicates this), so here our old > heuristics fail. > > Since only the i915 driver has access to the VBT, this commit renames > the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM > controller to "pwm_pmic_backlight" so that the i915 driver can do a > pwm_get() for the right controller depending on the VBT bit, instead of > the i915 driver relying on a "pwm_backlight" lookup getting registered > which magically points to the right controller. > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > drivers/mfd/intel_soc_pmic_core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) For my own reference: Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
Hi Lee, On 10-12-2019 09:51, Lee Jones wrote: > On Tue, 19 Nov 2019, Hans de Goede wrote: > >> At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 >> different PWM controllers for controlling the LCD's backlight brightness. >> >> Either the one integrated into the PMIC or the one integrated into the >> SoC (the 1st LPSS PWM controller). >> >> So far in the LPSS code on BYT we have skipped registering the LPSS PWM >> controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is >> present, assuming that in this case the PMIC PWM controller will be used. >> >> On CHT we have been relying on only 1 of the 2 PWM controllers being >> enabled in the DSDT at the same time; and always registered the lookup. >> >> So far this has been working, but the correct way to determine which PWM >> controller needs to be used is by checking a bit in the VBT table and >> recently I've learned about 2 different BYT devices: >> Point of View MOBII TAB-P800W >> Acer Switch 10 SW5-012 >> >> Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS >> PWM controller (and the VBT correctly indicates this), so here our old >> heuristics fail. >> >> Since only the i915 driver has access to the VBT, this commit renames >> the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM >> controller to "pwm_pmic_backlight" so that the i915 driver can do a >> pwm_get() for the right controller depending on the VBT bit, instead of >> the i915 driver relying on a "pwm_backlight" lookup getting registered >> which magically points to the right controller. >> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >> --- >> drivers/mfd/intel_soc_pmic_core.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) > > For my own reference: > Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> As mentioned in the cover-letter, to avoid breaking bi-sectability as well as to avoid breaking the intel-gfx CI we need to merge this series in one go through one tree. Specifically through the drm-intel tree. Is that ok with you ? If this is ok with you, then you do not have to do anything, I will just push the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c does not see much changes so I do not expect this to lead to any conflicts. Regards, Hans
On Wed, 11 Dec 2019, Hans de Goede wrote: > Hi Lee, > > On 10-12-2019 09:51, Lee Jones wrote: > > On Tue, 19 Nov 2019, Hans de Goede wrote: > > > > > At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 > > > different PWM controllers for controlling the LCD's backlight brightness. > > > > > > Either the one integrated into the PMIC or the one integrated into the > > > SoC (the 1st LPSS PWM controller). > > > > > > So far in the LPSS code on BYT we have skipped registering the LPSS PWM > > > controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is > > > present, assuming that in this case the PMIC PWM controller will be used. > > > > > > On CHT we have been relying on only 1 of the 2 PWM controllers being > > > enabled in the DSDT at the same time; and always registered the lookup. > > > > > > So far this has been working, but the correct way to determine which PWM > > > controller needs to be used is by checking a bit in the VBT table and > > > recently I've learned about 2 different BYT devices: > > > Point of View MOBII TAB-P800W > > > Acer Switch 10 SW5-012 > > > > > > Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS > > > PWM controller (and the VBT correctly indicates this), so here our old > > > heuristics fail. > > > > > > Since only the i915 driver has access to the VBT, this commit renames > > > the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM > > > controller to "pwm_pmic_backlight" so that the i915 driver can do a > > > pwm_get() for the right controller depending on the VBT bit, instead of > > > the i915 driver relying on a "pwm_backlight" lookup getting registered > > > which magically points to the right controller. > > > > > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > > > --- > > > drivers/mfd/intel_soc_pmic_core.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > For my own reference: > > Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> > > As mentioned in the cover-letter, to avoid breaking bi-sectability > as well as to avoid breaking the intel-gfx CI we need to merge this series > in one go through one tree. Specifically through the drm-intel tree. > Is that ok with you ? > > If this is ok with you, then you do not have to do anything, I will just push > the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c > does not see much changes so I do not expect this to lead to any conflicts. It's fine, so long as a minimal immutable pull-request is provided. Whether it's pulled or not will depend on a number of factors, but it needs to be an option.
Hi, On 12-12-2019 09:45, Lee Jones wrote: > On Wed, 11 Dec 2019, Hans de Goede wrote: > >> Hi Lee, >> >> On 10-12-2019 09:51, Lee Jones wrote: >>> On Tue, 19 Nov 2019, Hans de Goede wrote: >>> >>>> At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 >>>> different PWM controllers for controlling the LCD's backlight brightness. >>>> >>>> Either the one integrated into the PMIC or the one integrated into the >>>> SoC (the 1st LPSS PWM controller). >>>> >>>> So far in the LPSS code on BYT we have skipped registering the LPSS PWM >>>> controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is >>>> present, assuming that in this case the PMIC PWM controller will be used. >>>> >>>> On CHT we have been relying on only 1 of the 2 PWM controllers being >>>> enabled in the DSDT at the same time; and always registered the lookup. >>>> >>>> So far this has been working, but the correct way to determine which PWM >>>> controller needs to be used is by checking a bit in the VBT table and >>>> recently I've learned about 2 different BYT devices: >>>> Point of View MOBII TAB-P800W >>>> Acer Switch 10 SW5-012 >>>> >>>> Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS >>>> PWM controller (and the VBT correctly indicates this), so here our old >>>> heuristics fail. >>>> >>>> Since only the i915 driver has access to the VBT, this commit renames >>>> the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM >>>> controller to "pwm_pmic_backlight" so that the i915 driver can do a >>>> pwm_get() for the right controller depending on the VBT bit, instead of >>>> the i915 driver relying on a "pwm_backlight" lookup getting registered >>>> which magically points to the right controller. >>>> >>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >>>> --- >>>> drivers/mfd/intel_soc_pmic_core.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> For my own reference: >>> Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> >> >> As mentioned in the cover-letter, to avoid breaking bi-sectability >> as well as to avoid breaking the intel-gfx CI we need to merge this series >> in one go through one tree. Specifically through the drm-intel tree. >> Is that ok with you ? >> >> If this is ok with you, then you do not have to do anything, I will just push >> the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c >> does not see much changes so I do not expect this to lead to any conflicts. > > It's fine, so long as a minimal immutable pull-request is provided. > Whether it's pulled or not will depend on a number of factors, but it > needs to be an option. The way the drm subsys works that is not really a readily available option. The struct definition which this patch changes a single line in has not been touched since 2015-06-26 so I really doubt we will get a conflict from this. Regards, Hans
On Thu, 12 Dec 2019, Hans de Goede wrote: > Hi, > > On 12-12-2019 09:45, Lee Jones wrote: > > On Wed, 11 Dec 2019, Hans de Goede wrote: > > > > > Hi Lee, > > > > > > On 10-12-2019 09:51, Lee Jones wrote: > > > > On Tue, 19 Nov 2019, Hans de Goede wrote: > > > > > > > > > At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 > > > > > different PWM controllers for controlling the LCD's backlight brightness. > > > > > > > > > > Either the one integrated into the PMIC or the one integrated into the > > > > > SoC (the 1st LPSS PWM controller). > > > > > > > > > > So far in the LPSS code on BYT we have skipped registering the LPSS PWM > > > > > controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is > > > > > present, assuming that in this case the PMIC PWM controller will be used. > > > > > > > > > > On CHT we have been relying on only 1 of the 2 PWM controllers being > > > > > enabled in the DSDT at the same time; and always registered the lookup. > > > > > > > > > > So far this has been working, but the correct way to determine which PWM > > > > > controller needs to be used is by checking a bit in the VBT table and > > > > > recently I've learned about 2 different BYT devices: > > > > > Point of View MOBII TAB-P800W > > > > > Acer Switch 10 SW5-012 > > > > > > > > > > Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS > > > > > PWM controller (and the VBT correctly indicates this), so here our old > > > > > heuristics fail. > > > > > > > > > > Since only the i915 driver has access to the VBT, this commit renames > > > > > the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM > > > > > controller to "pwm_pmic_backlight" so that the i915 driver can do a > > > > > pwm_get() for the right controller depending on the VBT bit, instead of > > > > > the i915 driver relying on a "pwm_backlight" lookup getting registered > > > > > which magically points to the right controller. > > > > > > > > > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > > > > > --- > > > > > drivers/mfd/intel_soc_pmic_core.c | 2 +- > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > For my own reference: > > > > Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> > > > > > > As mentioned in the cover-letter, to avoid breaking bi-sectability > > > as well as to avoid breaking the intel-gfx CI we need to merge this series > > > in one go through one tree. Specifically through the drm-intel tree. > > > Is that ok with you ? > > > > > > If this is ok with you, then you do not have to do anything, I will just push > > > the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c > > > does not see much changes so I do not expect this to lead to any conflicts. > > > > It's fine, so long as a minimal immutable pull-request is provided. > > Whether it's pulled or not will depend on a number of factors, but it > > needs to be an option. > > The way the drm subsys works that is not really a readily available > option. The struct definition which this patch changes a single line in > has not been touched since 2015-06-26 so I really doubt we will get a > conflict from this. Always with the exceptions ... OOI, why does this *have* to go through the DRM tree?
Hi, On 12-12-2019 16:52, Lee Jones wrote: > On Thu, 12 Dec 2019, Hans de Goede wrote: > >> Hi, >> >> On 12-12-2019 09:45, Lee Jones wrote: >>> On Wed, 11 Dec 2019, Hans de Goede wrote: >>> >>>> Hi Lee, >>>> >>>> On 10-12-2019 09:51, Lee Jones wrote: >>>>> On Tue, 19 Nov 2019, Hans de Goede wrote: >>>>> >>>>>> At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 >>>>>> different PWM controllers for controlling the LCD's backlight brightness. >>>>>> >>>>>> Either the one integrated into the PMIC or the one integrated into the >>>>>> SoC (the 1st LPSS PWM controller). >>>>>> >>>>>> So far in the LPSS code on BYT we have skipped registering the LPSS PWM >>>>>> controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is >>>>>> present, assuming that in this case the PMIC PWM controller will be used. >>>>>> >>>>>> On CHT we have been relying on only 1 of the 2 PWM controllers being >>>>>> enabled in the DSDT at the same time; and always registered the lookup. >>>>>> >>>>>> So far this has been working, but the correct way to determine which PWM >>>>>> controller needs to be used is by checking a bit in the VBT table and >>>>>> recently I've learned about 2 different BYT devices: >>>>>> Point of View MOBII TAB-P800W >>>>>> Acer Switch 10 SW5-012 >>>>>> >>>>>> Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS >>>>>> PWM controller (and the VBT correctly indicates this), so here our old >>>>>> heuristics fail. >>>>>> >>>>>> Since only the i915 driver has access to the VBT, this commit renames >>>>>> the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM >>>>>> controller to "pwm_pmic_backlight" so that the i915 driver can do a >>>>>> pwm_get() for the right controller depending on the VBT bit, instead of >>>>>> the i915 driver relying on a "pwm_backlight" lookup getting registered >>>>>> which magically points to the right controller. >>>>>> >>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >>>>>> --- >>>>>> drivers/mfd/intel_soc_pmic_core.c | 2 +- >>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> For my own reference: >>>>> Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> >>>> >>>> As mentioned in the cover-letter, to avoid breaking bi-sectability >>>> as well as to avoid breaking the intel-gfx CI we need to merge this series >>>> in one go through one tree. Specifically through the drm-intel tree. >>>> Is that ok with you ? >>>> >>>> If this is ok with you, then you do not have to do anything, I will just push >>>> the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c >>>> does not see much changes so I do not expect this to lead to any conflicts. >>> >>> It's fine, so long as a minimal immutable pull-request is provided. >>> Whether it's pulled or not will depend on a number of factors, but it >>> needs to be an option. >> >> The way the drm subsys works that is not really a readily available >> option. The struct definition which this patch changes a single line in >> has not been touched since 2015-06-26 so I really doubt we will get a >> conflict from this. > > Always with the exceptions ... > > OOI, why does this *have* to go through the DRM tree? This patch renames the name used to lookup the pwm controller from "pwm_backlight" to "pwm_pmic_backlight" because there are 2 possible pwm controllers which may be used, one in the SoC itself and one in the PMIC. Which controller should be used is described in a table in the Video BIOS, so another part of this series adds this code to the i915 driver: - panel->backlight.pwm = pwm_get(dev->dev, "pwm_backlight"); + /* Get the right PWM chip for DSI backlight according to VBT */ + if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) { + panel->backlight.pwm = pwm_get(dev->dev, "pwm_pmic_backlight"); + desc = "PMIC"; + } else { + panel->backlight.pwm = pwm_get(dev->dev, "pwm_soc_backlight"); + desc = "SoC"; + } So both not to break bisectability, but also so as to not break the extensive CI system which is used to test the i915 driver we need the MFD change doing the rename to go upstrream through the same tree as the i915 change. I have even considered just squashing the 2 commits together as having only 1 present, but not the other breaks stuff left and right. Regards, Hans
On Thu, 12 Dec 2019, Hans de Goede wrote: > Hi, > > On 12-12-2019 16:52, Lee Jones wrote: > > On Thu, 12 Dec 2019, Hans de Goede wrote: > > > > > Hi, > > > > > > On 12-12-2019 09:45, Lee Jones wrote: > > > > On Wed, 11 Dec 2019, Hans de Goede wrote: > > > > > > > > > Hi Lee, > > > > > > > > > > On 10-12-2019 09:51, Lee Jones wrote: > > > > > > On Tue, 19 Nov 2019, Hans de Goede wrote: > > > > > > > > > > > > > At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 > > > > > > > different PWM controllers for controlling the LCD's backlight brightness. > > > > > > > > > > > > > > Either the one integrated into the PMIC or the one integrated into the > > > > > > > SoC (the 1st LPSS PWM controller). > > > > > > > > > > > > > > So far in the LPSS code on BYT we have skipped registering the LPSS PWM > > > > > > > controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is > > > > > > > present, assuming that in this case the PMIC PWM controller will be used. > > > > > > > > > > > > > > On CHT we have been relying on only 1 of the 2 PWM controllers being > > > > > > > enabled in the DSDT at the same time; and always registered the lookup. > > > > > > > > > > > > > > So far this has been working, but the correct way to determine which PWM > > > > > > > controller needs to be used is by checking a bit in the VBT table and > > > > > > > recently I've learned about 2 different BYT devices: > > > > > > > Point of View MOBII TAB-P800W > > > > > > > Acer Switch 10 SW5-012 > > > > > > > > > > > > > > Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS > > > > > > > PWM controller (and the VBT correctly indicates this), so here our old > > > > > > > heuristics fail. > > > > > > > > > > > > > > Since only the i915 driver has access to the VBT, this commit renames > > > > > > > the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM > > > > > > > controller to "pwm_pmic_backlight" so that the i915 driver can do a > > > > > > > pwm_get() for the right controller depending on the VBT bit, instead of > > > > > > > the i915 driver relying on a "pwm_backlight" lookup getting registered > > > > > > > which magically points to the right controller. > > > > > > > > > > > > > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > > > > > > > --- > > > > > > > drivers/mfd/intel_soc_pmic_core.c | 2 +- > > > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > > > For my own reference: > > > > > > Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> > > > > > > > > > > As mentioned in the cover-letter, to avoid breaking bi-sectability > > > > > as well as to avoid breaking the intel-gfx CI we need to merge this series > > > > > in one go through one tree. Specifically through the drm-intel tree. > > > > > Is that ok with you ? > > > > > > > > > > If this is ok with you, then you do not have to do anything, I will just push > > > > > the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c > > > > > does not see much changes so I do not expect this to lead to any conflicts. > > > > > > > > It's fine, so long as a minimal immutable pull-request is provided. > > > > Whether it's pulled or not will depend on a number of factors, but it > > > > needs to be an option. > > > > > > The way the drm subsys works that is not really a readily available > > > option. The struct definition which this patch changes a single line in > > > has not been touched since 2015-06-26 so I really doubt we will get a > > > conflict from this. > > > > Always with the exceptions ... > > > > OOI, why does this *have* to go through the DRM tree? > > This patch renames the name used to lookup the pwm controller from > "pwm_backlight" to "pwm_pmic_backlight" because there are 2 possible > pwm controllers which may be used, one in the SoC itself and one > in the PMIC. Which controller should be used is described in a table > in the Video BIOS, so another part of this series adds this code to > the i915 driver: > > - panel->backlight.pwm = pwm_get(dev->dev, "pwm_backlight"); > + /* Get the right PWM chip for DSI backlight according to VBT */ > + if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) { > + panel->backlight.pwm = pwm_get(dev->dev, "pwm_pmic_backlight"); > + desc = "PMIC"; > + } else { > + panel->backlight.pwm = pwm_get(dev->dev, "pwm_soc_backlight"); > + desc = "SoC"; > + } > > So both not to break bisectability, but also so as to not break the extensive > CI system which is used to test the i915 driver we need the MFD change doing > the rename to go upstrream through the same tree as the i915 change. > > I have even considered just squashing the 2 commits together as having only 1 > present, but not the other breaks stuff left and right. That doesn't answer the question. Why do they all *have* to go in via the DRM tree specifically?
Hi, On 13-12-2019 09:27, Lee Jones wrote: > On Thu, 12 Dec 2019, Hans de Goede wrote: > >> Hi, >> >> On 12-12-2019 16:52, Lee Jones wrote: >>> On Thu, 12 Dec 2019, Hans de Goede wrote: >>> >>>> Hi, >>>> >>>> On 12-12-2019 09:45, Lee Jones wrote: >>>>> On Wed, 11 Dec 2019, Hans de Goede wrote: >>>>> >>>>>> Hi Lee, >>>>>> >>>>>> On 10-12-2019 09:51, Lee Jones wrote: >>>>>>> On Tue, 19 Nov 2019, Hans de Goede wrote: >>>>>>> >>>>>>>> At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 >>>>>>>> different PWM controllers for controlling the LCD's backlight brightness. >>>>>>>> >>>>>>>> Either the one integrated into the PMIC or the one integrated into the >>>>>>>> SoC (the 1st LPSS PWM controller). >>>>>>>> >>>>>>>> So far in the LPSS code on BYT we have skipped registering the LPSS PWM >>>>>>>> controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is >>>>>>>> present, assuming that in this case the PMIC PWM controller will be used. >>>>>>>> >>>>>>>> On CHT we have been relying on only 1 of the 2 PWM controllers being >>>>>>>> enabled in the DSDT at the same time; and always registered the lookup. >>>>>>>> >>>>>>>> So far this has been working, but the correct way to determine which PWM >>>>>>>> controller needs to be used is by checking a bit in the VBT table and >>>>>>>> recently I've learned about 2 different BYT devices: >>>>>>>> Point of View MOBII TAB-P800W >>>>>>>> Acer Switch 10 SW5-012 >>>>>>>> >>>>>>>> Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS >>>>>>>> PWM controller (and the VBT correctly indicates this), so here our old >>>>>>>> heuristics fail. >>>>>>>> >>>>>>>> Since only the i915 driver has access to the VBT, this commit renames >>>>>>>> the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM >>>>>>>> controller to "pwm_pmic_backlight" so that the i915 driver can do a >>>>>>>> pwm_get() for the right controller depending on the VBT bit, instead of >>>>>>>> the i915 driver relying on a "pwm_backlight" lookup getting registered >>>>>>>> which magically points to the right controller. >>>>>>>> >>>>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >>>>>>>> --- >>>>>>>> drivers/mfd/intel_soc_pmic_core.c | 2 +- >>>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>>>> >>>>>>> For my own reference: >>>>>>> Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> >>>>>> >>>>>> As mentioned in the cover-letter, to avoid breaking bi-sectability >>>>>> as well as to avoid breaking the intel-gfx CI we need to merge this series >>>>>> in one go through one tree. Specifically through the drm-intel tree. >>>>>> Is that ok with you ? >>>>>> >>>>>> If this is ok with you, then you do not have to do anything, I will just push >>>>>> the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c >>>>>> does not see much changes so I do not expect this to lead to any conflicts. >>>>> >>>>> It's fine, so long as a minimal immutable pull-request is provided. >>>>> Whether it's pulled or not will depend on a number of factors, but it >>>>> needs to be an option. >>>> >>>> The way the drm subsys works that is not really a readily available >>>> option. The struct definition which this patch changes a single line in >>>> has not been touched since 2015-06-26 so I really doubt we will get a >>>> conflict from this. >>> >>> Always with the exceptions ... >>> >>> OOI, why does this *have* to go through the DRM tree? >> >> This patch renames the name used to lookup the pwm controller from >> "pwm_backlight" to "pwm_pmic_backlight" because there are 2 possible >> pwm controllers which may be used, one in the SoC itself and one >> in the PMIC. Which controller should be used is described in a table >> in the Video BIOS, so another part of this series adds this code to >> the i915 driver: >> >> - panel->backlight.pwm = pwm_get(dev->dev, "pwm_backlight"); >> + /* Get the right PWM chip for DSI backlight according to VBT */ >> + if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) { >> + panel->backlight.pwm = pwm_get(dev->dev, "pwm_pmic_backlight"); >> + desc = "PMIC"; >> + } else { >> + panel->backlight.pwm = pwm_get(dev->dev, "pwm_soc_backlight"); >> + desc = "SoC"; >> + } >> >> So both not to break bisectability, but also so as to not break the extensive >> CI system which is used to test the i915 driver we need the MFD change doing >> the rename to go upstrream through the same tree as the i915 change. >> >> I have even considered just squashing the 2 commits together as having only 1 >> present, but not the other breaks stuff left and right. > > That doesn't answer the question. > > Why do they all *have* to go in via the DRM tree specifically? 1. As explained these chanegs need to stay together 2. This change is primarily a drm/i915 change. Also the i915 code sees lots of changes every cycle, where as the change to the mfd code touches a block of code which has not been touched since 2015-06-26, so the chance of conflicts is much bigger if this goes on through another tree. I honestly do not see the problem here? Let me reverse the question why should this NOT go in through the drm tree? Regards, Hans
[...] > > > > > > > > > Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS > > > > > > > > > PWM controller (and the VBT correctly indicates this), so here our old > > > > > > > > > heuristics fail. > > > > > > > > > > > > > > > > > > Since only the i915 driver has access to the VBT, this commit renames > > > > > > > > > the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM > > > > > > > > > controller to "pwm_pmic_backlight" so that the i915 driver can do a > > > > > > > > > pwm_get() for the right controller depending on the VBT bit, instead of > > > > > > > > > the i915 driver relying on a "pwm_backlight" lookup getting registered > > > > > > > > > which magically points to the right controller. > > > > > > > > > > > > > > > > > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > > > > > > > > > --- > > > > > > > > > drivers/mfd/intel_soc_pmic_core.c | 2 +- > > > > > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > > > > > > > For my own reference: > > > > > > > > Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> > > > > > > > > > > > > > > As mentioned in the cover-letter, to avoid breaking bi-sectability > > > > > > > as well as to avoid breaking the intel-gfx CI we need to merge this series > > > > > > > in one go through one tree. Specifically through the drm-intel tree. > > > > > > > Is that ok with you ? > > > > > > > > > > > > > > If this is ok with you, then you do not have to do anything, I will just push > > > > > > > the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c > > > > > > > does not see much changes so I do not expect this to lead to any conflicts. > > > > > > > > > > > > It's fine, so long as a minimal immutable pull-request is provided. > > > > > > Whether it's pulled or not will depend on a number of factors, but it > > > > > > needs to be an option. > > > > > > > > > > The way the drm subsys works that is not really a readily available > > > > > option. The struct definition which this patch changes a single line in > > > > > has not been touched since 2015-06-26 so I really doubt we will get a > > > > > conflict from this. > > > > > > > > Always with the exceptions ... > > > > > > > > OOI, why does this *have* to go through the DRM tree? > > > > > > This patch renames the name used to lookup the pwm controller from > > > "pwm_backlight" to "pwm_pmic_backlight" because there are 2 possible > > > pwm controllers which may be used, one in the SoC itself and one > > > in the PMIC. Which controller should be used is described in a table > > > in the Video BIOS, so another part of this series adds this code to > > > the i915 driver: > > > > > > - panel->backlight.pwm = pwm_get(dev->dev, "pwm_backlight"); > > > + /* Get the right PWM chip for DSI backlight according to VBT */ > > > + if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) { > > > + panel->backlight.pwm = pwm_get(dev->dev, "pwm_pmic_backlight"); > > > + desc = "PMIC"; > > > + } else { > > > + panel->backlight.pwm = pwm_get(dev->dev, "pwm_soc_backlight"); > > > + desc = "SoC"; > > > + } > > > > > > So both not to break bisectability, but also so as to not break the extensive > > > CI system which is used to test the i915 driver we need the MFD change doing > > > the rename to go upstrream through the same tree as the i915 change. > > > > > > I have even considered just squashing the 2 commits together as having only 1 > > > present, but not the other breaks stuff left and right. > > > > That doesn't answer the question. > > > > Why do they all *have* to go in via the DRM tree specifically? > > 1. As explained these chanegs need to stay together > 2. This change is primarily a drm/i915 change. Also the i915 code sees lots > of changes every cycle, where as the change to the mfd code touches a block > of code which has not been touched since 2015-06-26, so the chance of conflicts > is much bigger if this goes on through another tree. > > I honestly do not see the problem here? Let me reverse the question why should this > NOT go in through the drm tree? There isn't a problem with *this* patch. I could say, "sure, take it" and the chances are everything could be fine from a technical perspective. However, I'm taking exception to the fact you think this series is *special* enough to warrant circumventing the usual way in which we usually work when dealing with cross-subsystem patch-sets. Something I personally deal with a lot due to the inherent hierarchical nature of Multi-Functional Devices. I'm on the fence on this one. Due to the circumstances surrounding *this* patch alone, it would be so much easier (for both of us!) to just Ack the patch and hope no further changes occur which could potentially cause someone else (you, me, Linus) more work later on. However, I'm very keen to prevent setting a precedent for this kind of action, as it's clearly not the right path to take in a vast majority of cases. > 1. As explained these chanegs need to stay together The patch-set would stay together regardless. That's the point of an immutable branch, it can be taken in by all relevant parties and Git will just do-the-right-thing. > 2. This change is primarily a drm/i915 change. Also the i915 code sees lots > of changes every cycle, where as the change to the mfd code touches a block > of code which has not been touched since 2015-06-26, so the chance of conflicts > is much bigger if this goes on through another tree. This too is irrelevant, since the patch-set could/would go though both/all trees simultaneously. The way in which we normally work with other subsystems doesn't involve a gamble over which subsystem is most likely going to be affected by a merge conflict as you suggest, it eradicates conflicts for all. I'm not saying "no" by the way. I just want to find out your reasons/motivation as to why you're insisting this needs go through a) a specific tree and b) just one tree. Questions which I am yet to see a compelling answer.
Hi, On 16-12-2019 10:30, Lee Jones wrote: > [...] > >>>>>>>>>> Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS >>>>>>>>>> PWM controller (and the VBT correctly indicates this), so here our old >>>>>>>>>> heuristics fail. >>>>>>>>>> >>>>>>>>>> Since only the i915 driver has access to the VBT, this commit renames >>>>>>>>>> the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM >>>>>>>>>> controller to "pwm_pmic_backlight" so that the i915 driver can do a >>>>>>>>>> pwm_get() for the right controller depending on the VBT bit, instead of >>>>>>>>>> the i915 driver relying on a "pwm_backlight" lookup getting registered >>>>>>>>>> which magically points to the right controller. >>>>>>>>>> >>>>>>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >>>>>>>>>> --- >>>>>>>>>> drivers/mfd/intel_soc_pmic_core.c | 2 +- >>>>>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>>>>>> >>>>>>>>> For my own reference: >>>>>>>>> Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> >>>>>>>> >>>>>>>> As mentioned in the cover-letter, to avoid breaking bi-sectability >>>>>>>> as well as to avoid breaking the intel-gfx CI we need to merge this series >>>>>>>> in one go through one tree. Specifically through the drm-intel tree. >>>>>>>> Is that ok with you ? >>>>>>>> >>>>>>>> If this is ok with you, then you do not have to do anything, I will just push >>>>>>>> the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c >>>>>>>> does not see much changes so I do not expect this to lead to any conflicts. >>>>>>> >>>>>>> It's fine, so long as a minimal immutable pull-request is provided. >>>>>>> Whether it's pulled or not will depend on a number of factors, but it >>>>>>> needs to be an option. >>>>>> >>>>>> The way the drm subsys works that is not really a readily available >>>>>> option. The struct definition which this patch changes a single line in >>>>>> has not been touched since 2015-06-26 so I really doubt we will get a >>>>>> conflict from this. >>>>> >>>>> Always with the exceptions ... >>>>> >>>>> OOI, why does this *have* to go through the DRM tree? >>>> >>>> This patch renames the name used to lookup the pwm controller from >>>> "pwm_backlight" to "pwm_pmic_backlight" because there are 2 possible >>>> pwm controllers which may be used, one in the SoC itself and one >>>> in the PMIC. Which controller should be used is described in a table >>>> in the Video BIOS, so another part of this series adds this code to >>>> the i915 driver: >>>> >>>> - panel->backlight.pwm = pwm_get(dev->dev, "pwm_backlight"); >>>> + /* Get the right PWM chip for DSI backlight according to VBT */ >>>> + if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) { >>>> + panel->backlight.pwm = pwm_get(dev->dev, "pwm_pmic_backlight"); >>>> + desc = "PMIC"; >>>> + } else { >>>> + panel->backlight.pwm = pwm_get(dev->dev, "pwm_soc_backlight"); >>>> + desc = "SoC"; >>>> + } >>>> >>>> So both not to break bisectability, but also so as to not break the extensive >>>> CI system which is used to test the i915 driver we need the MFD change doing >>>> the rename to go upstrream through the same tree as the i915 change. >>>> >>>> I have even considered just squashing the 2 commits together as having only 1 >>>> present, but not the other breaks stuff left and right. >>> >>> That doesn't answer the question. >>> >>> Why do they all *have* to go in via the DRM tree specifically? >> >> 1. As explained these chanegs need to stay together >> 2. This change is primarily a drm/i915 change. Also the i915 code sees lots >> of changes every cycle, where as the change to the mfd code touches a block >> of code which has not been touched since 2015-06-26, so the chance of conflicts >> is much bigger if this goes on through another tree. >> >> I honestly do not see the problem here? Let me reverse the question why should this >> NOT go in through the drm tree? > > There isn't a problem with *this* patch. I could say, "sure, take it" > and the chances are everything could be fine from a technical > perspective. > > However, I'm taking exception to the fact you think this series is > *special* enough to warrant circumventing the usual way in which we > usually work when dealing with cross-subsystem patch-sets. Something > I personally deal with a lot due to the inherent hierarchical nature > of Multi-Functional Devices. > > I'm on the fence on this one. Due to the circumstances surrounding > *this* patch alone, it would be so much easier (for both of us!) to > just Ack the patch and hope no further changes occur which could > potentially cause someone else (you, me, Linus) more work later on. > However, I'm very keen to prevent setting a precedent for this kind of > action, as it's clearly not the right path to take in a vast majority > of cases. > >> 1. As explained these chanegs need to stay together > > The patch-set would stay together regardless. That's the point of an > immutable branch, it can be taken in by all relevant parties and Git > will just do-the-right-thing. > >> 2. This change is primarily a drm/i915 change. Also the i915 code sees lots >> of changes every cycle, where as the change to the mfd code touches a block >> of code which has not been touched since 2015-06-26, so the chance of conflicts >> is much bigger if this goes on through another tree. > > This too is irrelevant, since the patch-set could/would go though > both/all trees simultaneously. The way in which we normally work with > other subsystems doesn't involve a gamble over which subsystem is most > likely going to be affected by a merge conflict as you suggest, it > eradicates conflicts for all. I'm well aware of using immutable branches and that those are often used for patch-set's which touch multiple subsystems. But although immutable branches are used often they are about as often not used for various reasons, with people choosing to just merge through a single tree. > I'm not saying "no" by the way. I just want to find out your > reasons/motivation as to why you're insisting this needs go through > a) a specific tree and b) just one tree. Questions which I am yet to > see a compelling answer. Doing immutable branches assumes that there is a base point, e.g. 5.5-rc1 where the immutable branch can then be based on and that the branch can then be merged without issues into both subsystems. drm is constantly evolving to deal with and mostly catch up with new hardware as both GPUs and display-pipelines are evolving quite rapidly atm drm-intel-next has about 400 commits on top of 5.5-rc1 so for an immutable branch I can either base it on drm-intel-next which violates your request for a clean minimal branch to merge; or I can base it on 5.5-rc1 which leads to a big chance of problems when merging it given to large amount of churn in drm-intel-next. So instead of the normal case of 2 subsystems seeing some changes on both side the case we have here is a part of a file which has not changed since 2015-06-26 in one subsys (and changing only a single line there!) and OTOH we have bigger changes to a subsys which see 400 patches land in the first week since rc1 . I hope that you agree that in this case given the large amount of churn in drm-intel-next it makes since to just straight forward apply these patches on top of drm-intel-next. Regards, Hans
On Mon, 16 Dec 2019, Hans de Goede wrote: > Hi, > > On 16-12-2019 10:30, Lee Jones wrote: > > [...] > > > > > > > > > > > > > Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS > > > > > > > > > > > PWM controller (and the VBT correctly indicates this), so here our old > > > > > > > > > > > heuristics fail. > > > > > > > > > > > > > > > > > > > > > > Since only the i915 driver has access to the VBT, this commit renames > > > > > > > > > > > the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM > > > > > > > > > > > controller to "pwm_pmic_backlight" so that the i915 driver can do a > > > > > > > > > > > pwm_get() for the right controller depending on the VBT bit, instead of > > > > > > > > > > > the i915 driver relying on a "pwm_backlight" lookup getting registered > > > > > > > > > > > which magically points to the right controller. > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > > > > > > > > > > > --- > > > > > > > > > > > drivers/mfd/intel_soc_pmic_core.c | 2 +- > > > > > > > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > > > > > > > > > > > For my own reference: > > > > > > > > > > Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> > > > > > > > > > > > > > > > > > > As mentioned in the cover-letter, to avoid breaking bi-sectability > > > > > > > > > as well as to avoid breaking the intel-gfx CI we need to merge this series > > > > > > > > > in one go through one tree. Specifically through the drm-intel tree. > > > > > > > > > Is that ok with you ? > > > > > > > > > > > > > > > > > > If this is ok with you, then you do not have to do anything, I will just push > > > > > > > > > the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c > > > > > > > > > does not see much changes so I do not expect this to lead to any conflicts. > > > > > > > > > > > > > > > > It's fine, so long as a minimal immutable pull-request is provided. > > > > > > > > Whether it's pulled or not will depend on a number of factors, but it > > > > > > > > needs to be an option. > > > > > > > > > > > > > > The way the drm subsys works that is not really a readily available > > > > > > > option. The struct definition which this patch changes a single line in > > > > > > > has not been touched since 2015-06-26 so I really doubt we will get a > > > > > > > conflict from this. > > > > > > > > > > > > Always with the exceptions ... > > > > > > > > > > > > OOI, why does this *have* to go through the DRM tree? > > > > > > > > > > This patch renames the name used to lookup the pwm controller from > > > > > "pwm_backlight" to "pwm_pmic_backlight" because there are 2 possible > > > > > pwm controllers which may be used, one in the SoC itself and one > > > > > in the PMIC. Which controller should be used is described in a table > > > > > in the Video BIOS, so another part of this series adds this code to > > > > > the i915 driver: > > > > > > > > > > - panel->backlight.pwm = pwm_get(dev->dev, "pwm_backlight"); > > > > > + /* Get the right PWM chip for DSI backlight according to VBT */ > > > > > + if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) { > > > > > + panel->backlight.pwm = pwm_get(dev->dev, "pwm_pmic_backlight"); > > > > > + desc = "PMIC"; > > > > > + } else { > > > > > + panel->backlight.pwm = pwm_get(dev->dev, "pwm_soc_backlight"); > > > > > + desc = "SoC"; > > > > > + } > > > > > > > > > > So both not to break bisectability, but also so as to not break the extensive > > > > > CI system which is used to test the i915 driver we need the MFD change doing > > > > > the rename to go upstrream through the same tree as the i915 change. > > > > > > > > > > I have even considered just squashing the 2 commits together as having only 1 > > > > > present, but not the other breaks stuff left and right. > > > > > > > > That doesn't answer the question. > > > > > > > > Why do they all *have* to go in via the DRM tree specifically? > > > > > > 1. As explained these chanegs need to stay together > > > 2. This change is primarily a drm/i915 change. Also the i915 code sees lots > > > of changes every cycle, where as the change to the mfd code touches a block > > > of code which has not been touched since 2015-06-26, so the chance of conflicts > > > is much bigger if this goes on through another tree. > > > > > > I honestly do not see the problem here? Let me reverse the question why should this > > > NOT go in through the drm tree? > > > > There isn't a problem with *this* patch. I could say, "sure, take it" > > and the chances are everything could be fine from a technical > > perspective. > > > > However, I'm taking exception to the fact you think this series is > > *special* enough to warrant circumventing the usual way in which we > > usually work when dealing with cross-subsystem patch-sets. Something > > I personally deal with a lot due to the inherent hierarchical nature > > of Multi-Functional Devices. > > > > I'm on the fence on this one. Due to the circumstances surrounding > > *this* patch alone, it would be so much easier (for both of us!) to > > just Ack the patch and hope no further changes occur which could > > potentially cause someone else (you, me, Linus) more work later on. > > However, I'm very keen to prevent setting a precedent for this kind of > > action, as it's clearly not the right path to take in a vast majority > > of cases. > > > > > 1. As explained these chanegs need to stay together > > > > The patch-set would stay together regardless. That's the point of an > > immutable branch, it can be taken in by all relevant parties and Git > > will just do-the-right-thing. > > > > > 2. This change is primarily a drm/i915 change. Also the i915 code sees lots > > > of changes every cycle, where as the change to the mfd code touches a block > > > of code which has not been touched since 2015-06-26, so the chance of conflicts > > > is much bigger if this goes on through another tree. > > > > This too is irrelevant, since the patch-set could/would go though > > both/all trees simultaneously. The way in which we normally work with > > other subsystems doesn't involve a gamble over which subsystem is most > > likely going to be affected by a merge conflict as you suggest, it > > eradicates conflicts for all. > > I'm well aware of using immutable branches and that those are > often used for patch-set's which touch multiple subsystems. But > although immutable branches are used often they are about as often > not used for various reasons, with people choosing to just merge > through a single tree. > > I'm not saying "no" by the way. I just want to find out your > > reasons/motivation as to why you're insisting this needs go through > > a) a specific tree and b) just one tree. Questions which I am yet to > > see a compelling answer. > > Doing immutable branches assumes that there is a base point, > e.g. 5.5-rc1 where the immutable branch can then be based on and > that the branch can then be merged without issues into both subsystems. > > drm is constantly evolving to deal with and mostly catch up with new > hardware as both GPUs and display-pipelines are evolving quite rapidly > atm drm-intel-next has about 400 commits on top of 5.5-rc1 so for an > immutable branch I can either base it on drm-intel-next which > violates your request for a clean minimal branch to merge; or I can > base it on 5.5-rc1 which leads to a big chance of problems when > merging it given to large amount of churn in drm-intel-next. This is a *slightly* more compelling reason than the ones you've previously provided. > So instead of the normal case of 2 subsystems seeing some changes > on both side the case we have here is a part of a file which has > not changed since 2015-06-26 in one subsys (and changing only > a single line there!) and OTOH we have bigger changes to a subsys > which see 400 patches land in the first week since rc1 . This is not. > I hope that you agree that in this case given the large amount of > churn in drm-intel-next it makes since to just straight forward > apply these patches on top of drm-intel-next. I have Acked this patch, but remember *this* is the exception rather than the rule. If/when we have a case where a contributor works cross-subsystem with DRM and the code/file adapted is live (more likely to change), I will have to insist on an immutable branch strategy. DRM will have to deal with that appropriately.
On Tue, 17 Dec 2019, Lee Jones <lee.jones@linaro.org> wrote: > On Mon, 16 Dec 2019, Hans de Goede wrote: > >> Hi, >> >> Doing immutable branches assumes that there is a base point, >> e.g. 5.5-rc1 where the immutable branch can then be based on and >> that the branch can then be merged without issues into both subsystems. >> >> drm is constantly evolving to deal with and mostly catch up with new >> hardware as both GPUs and display-pipelines are evolving quite rapidly >> atm drm-intel-next has about 400 commits on top of 5.5-rc1 so for an >> immutable branch I can either base it on drm-intel-next which >> violates your request for a clean minimal branch to merge; or I can >> base it on 5.5-rc1 which leads to a big chance of problems when >> merging it given to large amount of churn in drm-intel-next. > > This is a *slightly* more compelling reason than the ones you've > previously provided. > >> So instead of the normal case of 2 subsystems seeing some changes >> on both side the case we have here is a part of a file which has >> not changed since 2015-06-26 in one subsys (and changing only >> a single line there!) and OTOH we have bigger changes to a subsys >> which see 400 patches land in the first week since rc1 . > > This is not. > >> I hope that you agree that in this case given the large amount of >> churn in drm-intel-next it makes since to just straight forward >> apply these patches on top of drm-intel-next. > > I have Acked this patch, but remember *this* is the exception rather > than the rule. If/when we have a case where a contributor works > cross-subsystem with DRM and the code/file adapted is live (more > likely to change), I will have to insist on an immutable branch > strategy. DRM will have to deal with that appropriately. Hi, thanks for the ack and reaching an agreement with Hans, and sorry for not responding earlier. It's not unusual for us to have topic branches for cross-subsystem or cross-driver changes, and I think usually we try to be accommodating in merging stuff through whichever tree it makes most sense. In fact my ack to do just that was my first response on this series [1]. So I don't really know why the fuss. We'll anyway deal with any cross-subsystem series on a case by case basis, depending on what makes most sense, and what suits all maintainers involved. Thanks again, Jani. [1] http://mid.mail-archive.com/87pnhnyir8.fsf@intel.com
On Tue, 17 Dec 2019, Jani Nikula wrote: > On Tue, 17 Dec 2019, Lee Jones <lee.jones@linaro.org> wrote: > > On Mon, 16 Dec 2019, Hans de Goede wrote: > > > >> Hi, > >> > >> Doing immutable branches assumes that there is a base point, > >> e.g. 5.5-rc1 where the immutable branch can then be based on and > >> that the branch can then be merged without issues into both subsystems. > >> > >> drm is constantly evolving to deal with and mostly catch up with new > >> hardware as both GPUs and display-pipelines are evolving quite rapidly > >> atm drm-intel-next has about 400 commits on top of 5.5-rc1 so for an > >> immutable branch I can either base it on drm-intel-next which > >> violates your request for a clean minimal branch to merge; or I can > >> base it on 5.5-rc1 which leads to a big chance of problems when > >> merging it given to large amount of churn in drm-intel-next. > > > > This is a *slightly* more compelling reason than the ones you've > > previously provided. > > > >> So instead of the normal case of 2 subsystems seeing some changes > >> on both side the case we have here is a part of a file which has > >> not changed since 2015-06-26 in one subsys (and changing only > >> a single line there!) and OTOH we have bigger changes to a subsys > >> which see 400 patches land in the first week since rc1 . > > > > This is not. > > > >> I hope that you agree that in this case given the large amount of > >> churn in drm-intel-next it makes since to just straight forward > >> apply these patches on top of drm-intel-next. > > > > I have Acked this patch, but remember *this* is the exception rather > > than the rule. If/when we have a case where a contributor works > > cross-subsystem with DRM and the code/file adapted is live (more > > likely to change), I will have to insist on an immutable branch > > strategy. DRM will have to deal with that appropriately. > > Hi, thanks for the ack and reaching an agreement with Hans, and sorry > for not responding earlier. > > It's not unusual for us to have topic branches for cross-subsystem or > cross-driver changes, and I think usually we try to be accommodating in > merging stuff through whichever tree it makes most sense. In fact my ack > to do just that was my first response on this series [1]. > > So I don't really know why the fuss. We'll anyway deal with any > cross-subsystem series on a case by case basis, depending on what makes > most sense, and what suits all maintainers involved. Perfect. Thanks for the clarification. I look forward to working with you guys in the future. Hans was making the case that this was impractical for DRM, due to the amount of churn you guys receive, hence the discussion. I'm very pleased that this is not the case.
On Tue, 17 Dec 2019, Lee Jones <lee.jones@linaro.org> wrote: > Hans was making the case that this was impractical for DRM, due to the > amount of churn you guys receive, hence the discussion. I'm very > pleased that this is not the case. Heh, well, it is the case, but the point is that should be our problem, not yours. ;) BR, Jani.
On Wed, 18 Dec 2019, Jani Nikula wrote: > On Tue, 17 Dec 2019, Lee Jones <lee.jones@linaro.org> wrote: > > Hans was making the case that this was impractical for DRM, due to the > > amount of churn you guys receive, hence the discussion. I'm very > > pleased that this is not the case. > > Heh, well, it is the case, but the point is that should be our problem, > not yours. ;) :)
diff --git a/drivers/mfd/intel_soc_pmic_core.c b/drivers/mfd/intel_soc_pmic_core.c index c9f35378d391..47188df3080d 100644 --- a/drivers/mfd/intel_soc_pmic_core.c +++ b/drivers/mfd/intel_soc_pmic_core.c @@ -38,7 +38,7 @@ static struct gpiod_lookup_table panel_gpio_table = { /* PWM consumed by the Intel GFX */ static struct pwm_lookup crc_pwm_lookup[] = { - PWM_LOOKUP("crystal_cove_pwm", 0, "0000:00:02.0", "pwm_backlight", 0, PWM_POLARITY_NORMAL), + PWM_LOOKUP("crystal_cove_pwm", 0, "0000:00:02.0", "pwm_pmic_backlight", 0, PWM_POLARITY_NORMAL), }; static int intel_soc_pmic_i2c_probe(struct i2c_client *i2c,
At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 different PWM controllers for controlling the LCD's backlight brightness. Either the one integrated into the PMIC or the one integrated into the SoC (the 1st LPSS PWM controller). So far in the LPSS code on BYT we have skipped registering the LPSS PWM controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is present, assuming that in this case the PMIC PWM controller will be used. On CHT we have been relying on only 1 of the 2 PWM controllers being enabled in the DSDT at the same time; and always registered the lookup. So far this has been working, but the correct way to determine which PWM controller needs to be used is by checking a bit in the VBT table and recently I've learned about 2 different BYT devices: Point of View MOBII TAB-P800W Acer Switch 10 SW5-012 Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS PWM controller (and the VBT correctly indicates this), so here our old heuristics fail. Since only the i915 driver has access to the VBT, this commit renames the "pwm_backlight" lookup entries for the Crystal Cove PMIC's PWM controller to "pwm_pmic_backlight" so that the i915 driver can do a pwm_get() for the right controller depending on the VBT bit, instead of the i915 driver relying on a "pwm_backlight" lookup getting registered which magically points to the right controller. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/mfd/intel_soc_pmic_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)