| Message ID | 20180123174050.4261-1-rodrigo.vivi@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jan 23, 2018 at 05:40:50PM +0000, Rodrigo Vivi wrote: > Let's ignore VBT request if the pin is clearly wrong. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104139 > Cc: Kai Heng Feng <kai.heng.feng@canonical.com> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com> (f2f) thanks merged to dinq. > --- > drivers/gpu/drm/i915/intel_bios.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c > index b0668202dc7e..95f0b310d656 100644 > --- a/drivers/gpu/drm/i915/intel_bios.c > +++ b/drivers/gpu/drm/i915/intel_bios.c > @@ -1115,9 +1115,14 @@ static const u8 cnp_ddc_pin_map[] = { > > static u8 map_ddc_pin(struct drm_i915_private *dev_priv, u8 vbt_pin) > { > - if (HAS_PCH_CNP(dev_priv) && > - vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) > - return cnp_ddc_pin_map[vbt_pin]; > + if (HAS_PCH_CNP(dev_priv)) { > + if (vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) > + return cnp_ddc_pin_map[vbt_pin]; > + if (vbt_pin > GMBUS_PIN_4_CNP) { > + DRM_DEBUG_KMS("Ignoring alternate pin: VBT claims DDC pin %d, which is not valid for this platform\n", vbt_pin); > + return 0; > + } > + } > > return vbt_pin; > } > -- > 2.13.6 >
Hi, > On 24 Jan 2018, at 5:25 PM, Jani Nikula <jani.nikula@linux.intel.com> wrote: > A bit too fast IMO. The bug report doesn't include the vbt dump which > you should *always* look at before making workarounds for vbt. I didn’t have access to the machine in question until now, I can provide VBT dump as well as i915_opregion requested by Ville. But how do I make a VBT dump? Kai-Heng > > -- > Jani Nikula, Intel Open Source Technology Center
On Tue, 23 Jan 2018, Rodrigo Vivi <rodrigo.vivi@intel.com> wrote: > On Tue, Jan 23, 2018 at 05:40:50PM +0000, Rodrigo Vivi wrote: >> Let's ignore VBT request if the pin is clearly wrong. >> >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104139 >> Cc: Kai Heng Feng <kai.heng.feng@canonical.com> >> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > > Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com> > (f2f) > thanks > > merged to dinq. A bit too fast IMO. The bug report doesn't include the vbt dump which you should *always* look at before making workarounds for vbt. Also, see below. >> --- >> drivers/gpu/drm/i915/intel_bios.c | 11 ++++++++--- >> 1 file changed, 8 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c >> index b0668202dc7e..95f0b310d656 100644 >> --- a/drivers/gpu/drm/i915/intel_bios.c >> +++ b/drivers/gpu/drm/i915/intel_bios.c >> @@ -1115,9 +1115,14 @@ static const u8 cnp_ddc_pin_map[] = { >> >> static u8 map_ddc_pin(struct drm_i915_private *dev_priv, u8 vbt_pin) >> { >> - if (HAS_PCH_CNP(dev_priv) && >> - vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) >> - return cnp_ddc_pin_map[vbt_pin]; >> + if (HAS_PCH_CNP(dev_priv)) { >> + if (vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) >> + return cnp_ddc_pin_map[vbt_pin]; >> + if (vbt_pin > GMBUS_PIN_4_CNP) { >> + DRM_DEBUG_KMS("Ignoring alternate pin: VBT claims DDC pin %d, which is not valid for this platform\n", vbt_pin); >> + return 0; >> + } The original code was wrong in the sense that it would only do the mapping if the provided vbt_pin was within bounds for CNP, and would return the unmapped vbt_pin otherwise. Instead, I think you should directly return 0 for out of bounds vbt_pin. This change here is effectively the same, but more confusing. As if there's a case where the vbt_pin can be both out of bounds, within CNP pin limits, and should be returned unmapped. That can't happen, so please make the code reflect that. BR, Jani. >> + } >> >> return vbt_pin; >> } >> -- >> 2.13.6 >> > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
On Wed, 24 Jan 2018, Kai Heng Feng <kai.heng.feng@canonical.com> wrote: > Hi, > >> On 24 Jan 2018, at 5:25 PM, Jani Nikula <jani.nikula@linux.intel.com> wrote: >> A bit too fast IMO. The bug report doesn't include the vbt dump which >> you should *always* look at before making workarounds for vbt. > > I didn’t have access to the machine in question until now, I can provide > VBT dump as well as i915_opregion requested by Ville. > > But how do I make a VBT dump? Copy /sys/kernel/debug/dri/0/i915_vbt I don't think the opregion will be necessary, I think Ville asks for it for the vbt, which on most platforms is contained in the opregion. BR, Jani. > > Kai-Heng > >> >> -- >> Jani Nikula, Intel Open Source Technology Center >
> On 24 Jan 2018, at 6:03 PM, Jani Nikula <jani.nikula@linux.intel.com> wrote: > > On Wed, 24 Jan 2018, Kai Heng Feng <kai.heng.feng@canonical.com> wrote: >> Hi, >> >>> On 24 Jan 2018, at 5:25 PM, Jani Nikula <jani.nikula@linux.intel.com> wrote: >>> A bit too fast IMO. The bug report doesn't include the vbt dump which >>> you should *always* look at before making workarounds for vbt. >> >> I didn’t have access to the machine in question until now, I can provide >> VBT dump as well as i915_opregion requested by Ville. >> >> But how do I make a VBT dump? > > Copy /sys/kernel/debug/dri/0/i915_vbt > > I don't think the opregion will be necessary, I think Ville asks for it > for the vbt, which on most platforms is contained in the opregion. > Thanks for the tip. Attached i915_vbt: https://bugs.freedesktop.org/attachment.cgi?id=136935 Kai-Heng > BR, > Jani. > > >> >> Kai-Heng >> >>> >>> -- >>> Jani Nikula, Intel Open Source Technology Center >> > > -- > Jani Nikula, Intel Open Source Technology Center
On Wed, Jan 24, 2018 at 12:03:12PM +0200, Jani Nikula wrote: > On Wed, 24 Jan 2018, Kai Heng Feng <kai.heng.feng@canonical.com> wrote: > > Hi, > > > >> On 24 Jan 2018, at 5:25 PM, Jani Nikula <jani.nikula@linux.intel.com> wrote: > >> A bit too fast IMO. The bug report doesn't include the vbt dump which > >> you should *always* look at before making workarounds for vbt. > > > > I didn’t have access to the machine in question until now, I can provide > > VBT dump as well as i915_opregion requested by Ville. > > > > But how do I make a VBT dump? > > Copy /sys/kernel/debug/dri/0/i915_vbt > > I don't think the opregion will be necessary, I think Ville asks for it > for the vbt, which on most platforms is contained in the opregion. Old habits...
On Wed, Jan 24, 2018 at 09:25:06AM +0000, Jani Nikula wrote: > On Tue, 23 Jan 2018, Rodrigo Vivi <rodrigo.vivi@intel.com> wrote: > > On Tue, Jan 23, 2018 at 05:40:50PM +0000, Rodrigo Vivi wrote: > >> Let's ignore VBT request if the pin is clearly wrong. > >> > >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104139 > >> Cc: Kai Heng Feng <kai.heng.feng@canonical.com> > >> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > > > > Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com> > > (f2f) > > thanks > > > > merged to dinq. > > A bit too fast IMO. The bug report doesn't include the vbt dump which > you should *always* look at before making workarounds for vbt. my apologies. My biggest mistake was taking so long to reply to the bug and taking so long to post the patch here. :( I looked to the VBT now and it is really just this ddc pin for this particular port wrong. Or should I look to something else? What other kind of useful information would that bring to us normally? > > Also, see below. > > >> --- > >> drivers/gpu/drm/i915/intel_bios.c | 11 ++++++++--- > >> 1 file changed, 8 insertions(+), 3 deletions(-) > >> > >> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c > >> index b0668202dc7e..95f0b310d656 100644 > >> --- a/drivers/gpu/drm/i915/intel_bios.c > >> +++ b/drivers/gpu/drm/i915/intel_bios.c > >> @@ -1115,9 +1115,14 @@ static const u8 cnp_ddc_pin_map[] = { > >> > >> static u8 map_ddc_pin(struct drm_i915_private *dev_priv, u8 vbt_pin) > >> { > >> - if (HAS_PCH_CNP(dev_priv) && > >> - vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) > >> - return cnp_ddc_pin_map[vbt_pin]; > >> + if (HAS_PCH_CNP(dev_priv)) { > >> + if (vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) > >> + return cnp_ddc_pin_map[vbt_pin]; > >> + if (vbt_pin > GMBUS_PIN_4_CNP) { > >> + DRM_DEBUG_KMS("Ignoring alternate pin: VBT claims DDC pin %d, which is not valid for this platform\n", vbt_pin); > >> + return 0; > >> + } > > The original code was wrong in the sense that it would only do the > mapping if the provided vbt_pin was within bounds for CNP, and would > return the unmapped vbt_pin otherwise. Instead, I think you should > directly return 0 for out of bounds vbt_pin. > > This change here is effectively the same, but more confusing. As if > there's a case where the vbt_pin can be both out of bounds, within CNP > pin limits, and should be returned unmapped. That can't happen, so > please make the code reflect that. Yes. That's a great idea. Thanks for the suggestion. Honestly, at first I assumed our behavior was something like this so I couldn't believe we had the issue even with the original mapping there. But when I did the last fix I avoided changing the original behavior and messed things up. Sorry. Thanks, Rodrigo. > > BR, > Jani. > > > >> + } > >> > >> return vbt_pin; > >> } > >> -- > >> 2.13.6 > >> > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx > > -- > Jani Nikula, Intel Open Source Technology Center
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c index b0668202dc7e..95f0b310d656 100644 --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -1115,9 +1115,14 @@ static const u8 cnp_ddc_pin_map[] = { static u8 map_ddc_pin(struct drm_i915_private *dev_priv, u8 vbt_pin) { - if (HAS_PCH_CNP(dev_priv) && - vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) - return cnp_ddc_pin_map[vbt_pin]; + if (HAS_PCH_CNP(dev_priv)) { + if (vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) + return cnp_ddc_pin_map[vbt_pin]; + if (vbt_pin > GMBUS_PIN_4_CNP) { + DRM_DEBUG_KMS("Ignoring alternate pin: VBT claims DDC pin %d, which is not valid for this platform\n", vbt_pin); + return 0; + } + } return vbt_pin; }
Let's ignore VBT request if the pin is clearly wrong. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104139 Cc: Kai Heng Feng <kai.heng.feng@canonical.com> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> --- drivers/gpu/drm/i915/intel_bios.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)