| Message ID | 1591009402-681-1-git-send-email-mkrishn@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm/msm: add shutdown support for display platform_driver | expand |
Hi Krishna, On Tue, 2 Jun 2020 at 08:17, Krishna Manikandan <mkrishn@codeaurora.org> wrote: > > Define shutdown callback for display drm driver, > so as to disable all the CRTCS when shutdown > notification is received by the driver. > > This change will turn off the timing engine so > that no display transactions are requested > while mmu translations are getting disabled > during reboot sequence. > > Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org> > AFAICT atomics is setup in msm_drm_ops::bind and shutdown in msm_drm_ops::unbind. Are you saying that unbind never triggers? If so, then we should really fix that instead, since this patch seems more like a workaround. -Emil
Hi Emil, On 2020-06-02 19:43, Emil Velikov wrote: > Hi Krishna, > > On Tue, 2 Jun 2020 at 08:17, Krishna Manikandan > <mkrishn@codeaurora.org> wrote: >> >> Define shutdown callback for display drm driver, >> so as to disable all the CRTCS when shutdown >> notification is received by the driver. >> >> This change will turn off the timing engine so >> that no display transactions are requested >> while mmu translations are getting disabled >> during reboot sequence. >> >> Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org> >> > AFAICT atomics is setup in msm_drm_ops::bind and shutdown in > msm_drm_ops::unbind. > > Are you saying that unbind never triggers? If so, then we should > really fix that instead, since this patch seems more like a > workaround. > Which path do you suppose that the unbind should be called from, remove callback? Here we are talking about the drivers which are builtin, where remove callbacks are not called from the driver core during reboot/shutdown, instead shutdown callbacks are called which needs to be defined in order to trigger unbind. So AFAICS there is nothing to be fixed. msm_pdev_shutdown() platform_drv_shutdown() device_shutdown() kernel_restart_prepare() kernel_restart() __arm64_sys_reboot() Thanks, Sai
On Tue, 2 Jun 2020 at 15:49, Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> wrote: > > Hi Emil, > > On 2020-06-02 19:43, Emil Velikov wrote: > > Hi Krishna, > > > > On Tue, 2 Jun 2020 at 08:17, Krishna Manikandan > > <mkrishn@codeaurora.org> wrote: > >> > >> Define shutdown callback for display drm driver, > >> so as to disable all the CRTCS when shutdown > >> notification is received by the driver. > >> > >> This change will turn off the timing engine so > >> that no display transactions are requested > >> while mmu translations are getting disabled > >> during reboot sequence. > >> > >> Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org> > >> > > AFAICT atomics is setup in msm_drm_ops::bind and shutdown in > > msm_drm_ops::unbind. > > > > Are you saying that unbind never triggers? If so, then we should > > really fix that instead, since this patch seems more like a > > workaround. > > > > Which path do you suppose that the unbind should be called from, remove > callback? Here we are talking about the drivers which are builtin, where > remove callbacks are not called from the driver core during > reboot/shutdown, > instead shutdown callbacks are called which needs to be defined in order > to > trigger unbind. So AFAICS there is nothing to be fixed. > Interesting - in drm effectively only drm panels implement .shutdown. So my naive assumption was that .remove was used implicitly by core, as part of the shutdown process. Yet that's not the case, so it seems that many drivers could use some fixes. Then again, that's an existing problem which is irrelevant for msm. -Emil
Hi Emil, On 2020-06-02 21:09, Emil Velikov wrote: > On Tue, 2 Jun 2020 at 15:49, Sai Prakash Ranjan > <saiprakash.ranjan@codeaurora.org> wrote: >> >> Hi Emil, >> >> On 2020-06-02 19:43, Emil Velikov wrote: >> > Hi Krishna, >> > >> > On Tue, 2 Jun 2020 at 08:17, Krishna Manikandan >> > <mkrishn@codeaurora.org> wrote: >> >> >> >> Define shutdown callback for display drm driver, >> >> so as to disable all the CRTCS when shutdown >> >> notification is received by the driver. >> >> >> >> This change will turn off the timing engine so >> >> that no display transactions are requested >> >> while mmu translations are getting disabled >> >> during reboot sequence. >> >> >> >> Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org> >> >> >> > AFAICT atomics is setup in msm_drm_ops::bind and shutdown in >> > msm_drm_ops::unbind. >> > >> > Are you saying that unbind never triggers? If so, then we should >> > really fix that instead, since this patch seems more like a >> > workaround. >> > >> >> Which path do you suppose that the unbind should be called from, >> remove >> callback? Here we are talking about the drivers which are builtin, >> where >> remove callbacks are not called from the driver core during >> reboot/shutdown, >> instead shutdown callbacks are called which needs to be defined in >> order >> to >> trigger unbind. So AFAICS there is nothing to be fixed. >> > Interesting - in drm effectively only drm panels implement .shutdown. > So my naive assumption was that .remove was used implicitly by core, > as part of the shutdown process. Yet that's not the case, so it seems > that many drivers could use some fixes. > > Then again, that's an existing problem which is irrelevant for msm. > -Emil To give more context, we are actually targeting the clients/consumers of SMMU/IOMMU here because we have to make sure that before the supplier (SMMU) shuts down, its consumers/clients need to be shutdown properly. Now the ordering of this is taken care in the SMMU driver via device_link which makes sure that consumer shutdown callbacks are called first, but we need to define shutdown callbacks for all its consumers to make sure we actually shutdown the clients or else it would invite the crashes during reboot which in this case was seen for display. Thanks, Sai
On Tue, 2 Jun 2020 at 17:10, Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> wrote: > > Hi Emil, > > On 2020-06-02 21:09, Emil Velikov wrote: > > On Tue, 2 Jun 2020 at 15:49, Sai Prakash Ranjan > > <saiprakash.ranjan@codeaurora.org> wrote: > >> > >> Hi Emil, > >> > >> On 2020-06-02 19:43, Emil Velikov wrote: > >> > Hi Krishna, > >> > > >> > On Tue, 2 Jun 2020 at 08:17, Krishna Manikandan > >> > <mkrishn@codeaurora.org> wrote: > >> >> > >> >> Define shutdown callback for display drm driver, > >> >> so as to disable all the CRTCS when shutdown > >> >> notification is received by the driver. > >> >> > >> >> This change will turn off the timing engine so > >> >> that no display transactions are requested > >> >> while mmu translations are getting disabled > >> >> during reboot sequence. > >> >> > >> >> Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org> > >> >> > >> > AFAICT atomics is setup in msm_drm_ops::bind and shutdown in > >> > msm_drm_ops::unbind. > >> > > >> > Are you saying that unbind never triggers? If so, then we should > >> > really fix that instead, since this patch seems more like a > >> > workaround. > >> > > >> > >> Which path do you suppose that the unbind should be called from, > >> remove > >> callback? Here we are talking about the drivers which are builtin, > >> where > >> remove callbacks are not called from the driver core during > >> reboot/shutdown, > >> instead shutdown callbacks are called which needs to be defined in > >> order > >> to > >> trigger unbind. So AFAICS there is nothing to be fixed. > >> > > Interesting - in drm effectively only drm panels implement .shutdown. > > So my naive assumption was that .remove was used implicitly by core, > > as part of the shutdown process. Yet that's not the case, so it seems > > that many drivers could use some fixes. > > > > Then again, that's an existing problem which is irrelevant for msm. > > -Emil > > To give more context, we are actually targeting the clients/consumers > of SMMU/IOMMU here because we have to make sure that before the supplier > (SMMU) shuts down, its consumers/clients need to be shutdown properly. > Now the ordering of this is taken care in the SMMU driver via > device_link > which makes sure that consumer shutdown callbacks are called first, but > we > need to define shutdown callbacks for all its consumers to make sure we > actually shutdown the clients or else it would invite the crashes during > reboot > which in this case was seen for display. > Thank you very much for the extra details. I think other DRM drivers will be safe as-is. -Emil
Hi, On 2020-06-01 16:33, Krishna Manikandan wrote: > Define shutdown callback for display drm driver, > so as to disable all the CRTCS when shutdown > notification is received by the driver. > > This change will turn off the timing engine so > that no display transactions are requested > while mmu translations are getting disabled > during reboot sequence. > > Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org> > > Changes in v2: > - Remove NULL check from msm_pdev_shutdown (Stephen Boyd) > - Change commit text to reflect when this issue > was uncovered (Sai Prakash Ranjan) > --- > drivers/gpu/drm/msm/msm_drv.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/gpu/drm/msm/msm_drv.c > b/drivers/gpu/drm/msm/msm_drv.c > index e4b750b..94e3963 100644 > --- a/drivers/gpu/drm/msm/msm_drv.c > +++ b/drivers/gpu/drm/msm/msm_drv.c > @@ -1322,6 +1322,13 @@ static int msm_pdev_remove(struct > platform_device *pdev) > return 0; > } > > +static void msm_pdev_shutdown(struct platform_device *pdev) > +{ > + struct drm_device *drm = platform_get_drvdata(pdev); > + > + drm_atomic_helper_shutdown(drm); > +} > + > static const struct of_device_id dt_match[] = { > { .compatible = "qcom,mdp4", .data = (void *)KMS_MDP4 }, > { .compatible = "qcom,mdss", .data = (void *)KMS_MDP5 }, > @@ -1334,6 +1341,7 @@ static int msm_pdev_remove(struct platform_device > *pdev) > static struct platform_driver msm_platform_driver = { > .probe = msm_pdev_probe, > .remove = msm_pdev_remove, > + .shutdown = msm_pdev_shutdown, > .driver = { > .name = "msm", > .of_match_table = dt_match, Any more comments on this patch? Thanks, Sai
On Tue, Aug 18, 2020 at 3:03 AM Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> wrote: > > Hi, > > On 2020-06-01 16:33, Krishna Manikandan wrote: > > Define shutdown callback for display drm driver, > > so as to disable all the CRTCS when shutdown > > notification is received by the driver. > > > > This change will turn off the timing engine so > > that no display transactions are requested > > while mmu translations are getting disabled > > during reboot sequence. > > > > Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org> > > > > Changes in v2: > > - Remove NULL check from msm_pdev_shutdown (Stephen Boyd) > > - Change commit text to reflect when this issue > > was uncovered (Sai Prakash Ranjan) > > --- > > drivers/gpu/drm/msm/msm_drv.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/drivers/gpu/drm/msm/msm_drv.c > > b/drivers/gpu/drm/msm/msm_drv.c > > index e4b750b..94e3963 100644 > > --- a/drivers/gpu/drm/msm/msm_drv.c > > +++ b/drivers/gpu/drm/msm/msm_drv.c > > @@ -1322,6 +1322,13 @@ static int msm_pdev_remove(struct > > platform_device *pdev) > > return 0; > > } > > > > +static void msm_pdev_shutdown(struct platform_device *pdev) > > +{ > > + struct drm_device *drm = platform_get_drvdata(pdev); > > + > > + drm_atomic_helper_shutdown(drm); > > +} > > + > > static const struct of_device_id dt_match[] = { > > { .compatible = "qcom,mdp4", .data = (void *)KMS_MDP4 }, > > { .compatible = "qcom,mdss", .data = (void *)KMS_MDP5 }, > > @@ -1334,6 +1341,7 @@ static int msm_pdev_remove(struct platform_device > > *pdev) > > static struct platform_driver msm_platform_driver = { > > .probe = msm_pdev_probe, > > .remove = msm_pdev_remove, > > + .shutdown = msm_pdev_shutdown, > > .driver = { > > .name = "msm", > > .of_match_table = dt_match, > > Any more comments on this patch? sorry, I managed to overlook this earlier.. I've pulled it in to msm-next BR, -R > Thanks, > Sai > > -- > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a > member > of Code Aurora Forum, hosted by The Linux Foundation
On 2020-08-18 20:42, Rob Clark wrote: > On Tue, Aug 18, 2020 at 3:03 AM Sai Prakash Ranjan > <saiprakash.ranjan@codeaurora.org> wrote: >> >> Hi, >> >> On 2020-06-01 16:33, Krishna Manikandan wrote: >> > Define shutdown callback for display drm driver, >> > so as to disable all the CRTCS when shutdown >> > notification is received by the driver. >> > >> > This change will turn off the timing engine so >> > that no display transactions are requested >> > while mmu translations are getting disabled >> > during reboot sequence. >> > >> > Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org> >> > >> > Changes in v2: >> > - Remove NULL check from msm_pdev_shutdown (Stephen Boyd) >> > - Change commit text to reflect when this issue >> > was uncovered (Sai Prakash Ranjan) >> > --- >> > drivers/gpu/drm/msm/msm_drv.c | 8 ++++++++ >> > 1 file changed, 8 insertions(+) >> > >> > diff --git a/drivers/gpu/drm/msm/msm_drv.c >> > b/drivers/gpu/drm/msm/msm_drv.c >> > index e4b750b..94e3963 100644 >> > --- a/drivers/gpu/drm/msm/msm_drv.c >> > +++ b/drivers/gpu/drm/msm/msm_drv.c >> > @@ -1322,6 +1322,13 @@ static int msm_pdev_remove(struct >> > platform_device *pdev) >> > return 0; >> > } >> > >> > +static void msm_pdev_shutdown(struct platform_device *pdev) >> > +{ >> > + struct drm_device *drm = platform_get_drvdata(pdev); >> > + >> > + drm_atomic_helper_shutdown(drm); >> > +} >> > + >> > static const struct of_device_id dt_match[] = { >> > { .compatible = "qcom,mdp4", .data = (void *)KMS_MDP4 }, >> > { .compatible = "qcom,mdss", .data = (void *)KMS_MDP5 }, >> > @@ -1334,6 +1341,7 @@ static int msm_pdev_remove(struct platform_device >> > *pdev) >> > static struct platform_driver msm_platform_driver = { >> > .probe = msm_pdev_probe, >> > .remove = msm_pdev_remove, >> > + .shutdown = msm_pdev_shutdown, >> > .driver = { >> > .name = "msm", >> > .of_match_table = dt_match, >> >> Any more comments on this patch? > > sorry, I managed to overlook this earlier.. I've pulled it in to > msm-next > No problem, thanks Rob. -Sai
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index e4b750b..94e3963 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -1322,6 +1322,13 @@ static int msm_pdev_remove(struct platform_device *pdev) return 0; } +static void msm_pdev_shutdown(struct platform_device *pdev) +{ + struct drm_device *drm = platform_get_drvdata(pdev); + + drm_atomic_helper_shutdown(drm); +} + static const struct of_device_id dt_match[] = { { .compatible = "qcom,mdp4", .data = (void *)KMS_MDP4 }, { .compatible = "qcom,mdss", .data = (void *)KMS_MDP5 }, @@ -1334,6 +1341,7 @@ static int msm_pdev_remove(struct platform_device *pdev) static struct platform_driver msm_platform_driver = { .probe = msm_pdev_probe, .remove = msm_pdev_remove, + .shutdown = msm_pdev_shutdown, .driver = { .name = "msm", .of_match_table = dt_match,
Define shutdown callback for display drm driver, so as to disable all the CRTCS when shutdown notification is received by the driver. This change will turn off the timing engine so that no display transactions are requested while mmu translations are getting disabled during reboot sequence. Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org> Changes in v2: - Remove NULL check from msm_pdev_shutdown (Stephen Boyd) - Change commit text to reflect when this issue was uncovered (Sai Prakash Ranjan) --- drivers/gpu/drm/msm/msm_drv.c | 8 ++++++++ 1 file changed, 8 insertions(+)