| Message ID | 1584944027-1730-1-git-send-email-kalyan_t@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/msm/dpu: ensure device suspend happens during PM sleep | expand |
Hi, On Sun, Mar 22, 2020 at 11:14 PM Kalyan Thota <kalyan_t@codeaurora.org> wrote: > > "The PM core always increments the runtime usage counter > before calling the ->suspend() callback and decrements it > after calling the ->resume() callback" > > DPU and DSI are managed as runtime devices. When > suspend is triggered, PM core adds a refcount on all the > devices and calls device suspend, since usage count is > already incremented, runtime suspend was not getting called > and it kept the clocks on which resulted in target not > entering into XO shutdown. > > Add changes to manage runtime devices during pm sleep. > > Changes in v1: > - Remove unnecessary checks in the function > _dpu_kms_disable_dpu (Rob Clark). I'm wondering what happened with my feedback on v1, AKA: https://lore.kernel.org/r/CAD=FV=VxzEV40g+ieuEN+7o=34+wM8MHO8o7T5zA1Yosx7SVWg@mail.gmail.com Maybe you didn't see it? ...or if you or Rob think I'm way off base (always possible) then please tell me so. Thanks! -Doug
On Tue, Mar 24, 2020 at 7:35 AM Doug Anderson <dianders@chromium.org> wrote: > > Hi, > > On Sun, Mar 22, 2020 at 11:14 PM Kalyan Thota <kalyan_t@codeaurora.org> wrote: > > > > "The PM core always increments the runtime usage counter > > before calling the ->suspend() callback and decrements it > > after calling the ->resume() callback" > > > > DPU and DSI are managed as runtime devices. When > > suspend is triggered, PM core adds a refcount on all the > > devices and calls device suspend, since usage count is > > already incremented, runtime suspend was not getting called > > and it kept the clocks on which resulted in target not > > entering into XO shutdown. > > > > Add changes to manage runtime devices during pm sleep. > > > > Changes in v1: > > - Remove unnecessary checks in the function > > _dpu_kms_disable_dpu (Rob Clark). > > I'm wondering what happened with my feedback on v1, AKA: > > https://lore.kernel.org/r/CAD=FV=VxzEV40g+ieuEN+7o=34+wM8MHO8o7T5zA1Yosx7SVWg@mail.gmail.com > > Maybe you didn't see it? ...or if you or Rob think I'm way off base > (always possible) then please tell me so. > At least w/ the current patch, disable_dpu should not be called for screen-off (although I'd hope if all the screens are off the device would suspend). But I won't claim to be a pm expert.. so not really sure if this is the best approach or not. I don't think our arrangement of sub-devices under a parent is completely abnormal, so it does feel like there should be a simpler solution.. BR, -R
Hi, On Wed, Mar 25, 2020 at 8:40 AM Rob Clark <robdclark@gmail.com> wrote: > > On Tue, Mar 24, 2020 at 7:35 AM Doug Anderson <dianders@chromium.org> wrote: > > > > Hi, > > > > On Sun, Mar 22, 2020 at 11:14 PM Kalyan Thota <kalyan_t@codeaurora.org> wrote: > > > > > > "The PM core always increments the runtime usage counter > > > before calling the ->suspend() callback and decrements it > > > after calling the ->resume() callback" > > > > > > DPU and DSI are managed as runtime devices. When > > > suspend is triggered, PM core adds a refcount on all the > > > devices and calls device suspend, since usage count is > > > already incremented, runtime suspend was not getting called > > > and it kept the clocks on which resulted in target not > > > entering into XO shutdown. > > > > > > Add changes to manage runtime devices during pm sleep. > > > > > > Changes in v1: > > > - Remove unnecessary checks in the function > > > _dpu_kms_disable_dpu (Rob Clark). > > > > I'm wondering what happened with my feedback on v1, AKA: > > > > https://lore.kernel.org/r/CAD=FV=VxzEV40g+ieuEN+7o=34+wM8MHO8o7T5zA1Yosx7SVWg@mail.gmail.com > > > > Maybe you didn't see it? ...or if you or Rob think I'm way off base > > (always possible) then please tell me so. > > > > At least w/ the current patch, disable_dpu should not be called for > screen-off (although I'd hope if all the screens are off the device > would suspend). OK, that's good. > But I won't claim to be a pm expert.. so not really > sure if this is the best approach or not. I don't think our > arrangement of sub-devices under a parent is completely abnormal, so > it does feel like there should be a simpler solution.. I think the other arguments about asymmetry are still valid and I've fixed bugs around this type of thing in the past. For instance, see commit f7ccbed656f7 ("drm/rockchip: Suspend DP late"). -Doug
On 2020-03-25 21:20, Doug Anderson wrote: > Hi, > > On Wed, Mar 25, 2020 at 8:40 AM Rob Clark <robdclark@gmail.com> wrote: >> >> On Tue, Mar 24, 2020 at 7:35 AM Doug Anderson <dianders@chromium.org> >> wrote: >> > >> > Hi, >> > >> > On Sun, Mar 22, 2020 at 11:14 PM Kalyan Thota <kalyan_t@codeaurora.org> wrote: >> > > >> > > "The PM core always increments the runtime usage counter >> > > before calling the ->suspend() callback and decrements it >> > > after calling the ->resume() callback" >> > > >> > > DPU and DSI are managed as runtime devices. When >> > > suspend is triggered, PM core adds a refcount on all the >> > > devices and calls device suspend, since usage count is >> > > already incremented, runtime suspend was not getting called >> > > and it kept the clocks on which resulted in target not >> > > entering into XO shutdown. >> > > >> > > Add changes to manage runtime devices during pm sleep. >> > > >> > > Changes in v1: >> > > - Remove unnecessary checks in the function >> > > _dpu_kms_disable_dpu (Rob Clark). >> > >> > I'm wondering what happened with my feedback on v1, AKA: >> > >> > https://lore.kernel.org/r/CAD=FV=VxzEV40g+ieuEN+7o=34+wM8MHO8o7T5zA1Yosx7SVWg@mail.gmail.com >> > >> > Maybe you didn't see it? ...or if you or Rob think I'm way off base >> > (always possible) then please tell me so. >> > -- I didn't notice your comments earlier. Apologies !! >> >> At least w/ the current patch, disable_dpu should not be called for >> screen-off (although I'd hope if all the screens are off the device >> would suspend). > > OK, that's good. -- Rob has answered it, with current change disable_dpu will only be called during pm_suspend. > >> But I won't claim to be a pm expert.. so not really >> sure if this is the best approach or not. I don't think our >> arrangement of sub-devices under a parent is completely abnormal, so >> it does feel like there should be a simpler solution.. > > I think the other arguments about asymmetry are still valid and I've > fixed bugs around this type of thing in the past. For instance, see > commit f7ccbed656f7 ("drm/rockchip: Suspend DP late"). > * What happens if suspend is aborted partway through (by getting a wakeup even as you're suspending, for instance)? In such a case some of the normal suspend calls will be called but "suspend_late" won't be called. Does that mess up your counting? -- I understand this concern, i'll explore a bit more on how to handle "failed to suspend","early awake" cases (to restore the usage_count) since suspend_late wont be called. *From your description, it sure seems like this part of the runtime_pm.rst doc is relevant to you: Did I misunderstand and this isn't what you want? Looking a bit further, maybe the right thing is to use the "SMART_SUSPEND" flag? -- if you notice in the device_prepare (https://elixir.bootlin.com/linux/latest/source/drivers/base/power/main.c#L1913) there is a pm_runtime_get_noresume at L1931, which will increment the usagecount before triggering client prepare call, hence implementing prepare wont fetch us much. This appears to be more for the cases when device is runtime suspended and suspend followed later "one example usecase that i can think of, is screen timeout after that suspend is triggered" currently the problem i am looking at is that PM Core does +1 in device prepare DPU driver does -1 in suspend DPU driver does +1 in suspend late ( look for right place ) PM core does -1 in device complete i'll get back after exploring a bit. > > -Doug
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c index ce19f1d..c3e8287 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c @@ -26,6 +26,7 @@ #include "dpu_encoder.h" #include "dpu_plane.h" #include "dpu_crtc.h" +#include "dsi.h" #define CREATE_TRACE_POINTS #include "dpu_trace.h" @@ -325,6 +326,24 @@ static void dpu_kms_disable_commit(struct msm_kms *kms) pm_runtime_put_sync(&dpu_kms->pdev->dev); } +static void _dpu_kms_disable_dpu(struct msm_kms *kms) +{ + struct dpu_kms *dpu_kms = to_dpu_kms(kms); + struct drm_device *dev = dpu_kms->dev; + struct msm_drm_private *priv = dev->dev_private; + struct msm_dsi *dsi; + int i; + + dpu_kms_disable_commit(kms); + + for (i = 0; i < ARRAY_SIZE(priv->dsi); i++) { + if (!priv->dsi[i]) + continue; + dsi = priv->dsi[i]; + pm_runtime_put_sync(&dsi->pdev->dev); + } +} + static ktime_t dpu_kms_vsync_time(struct msm_kms *kms, struct drm_crtc *crtc) { struct drm_encoder *encoder; @@ -751,6 +770,7 @@ static void dpu_irq_uninstall(struct msm_kms *kms) #ifdef CONFIG_DEBUG_FS .debugfs_init = dpu_kms_debugfs_init, #endif + .disable_dpu = _dpu_kms_disable_dpu, }; static void _dpu_kms_mmu_destroy(struct dpu_kms *dpu_kms) @@ -1121,7 +1141,15 @@ static int __maybe_unused dpu_runtime_resume(struct device *dev) return rc; } + +static int __maybe_unused dpu_pm_suspend_late(struct device *dev) +{ + pm_runtime_get_noresume(dev); + return 0; +} + static const struct dev_pm_ops dpu_pm_ops = { + SET_LATE_SYSTEM_SLEEP_PM_OPS(dpu_pm_suspend_late, NULL) SET_RUNTIME_PM_OPS(dpu_runtime_suspend, dpu_runtime_resume, NULL) }; diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c index 55ea4bc2..3d3740e 100644 --- a/drivers/gpu/drm/msm/dsi/dsi.c +++ b/drivers/gpu/drm/msm/dsi/dsi.c @@ -154,12 +154,19 @@ static int dsi_dev_remove(struct platform_device *pdev) return 0; } +static int __maybe_unused dsi_pm_suspend_late(struct device *dev) +{ + pm_runtime_get_noresume(dev); + return 0; +} + static const struct of_device_id dt_match[] = { { .compatible = "qcom,mdss-dsi-ctrl" }, {} }; static const struct dev_pm_ops dsi_pm_ops = { + SET_LATE_SYSTEM_SLEEP_PM_OPS(dsi_pm_suspend_late, NULL) SET_RUNTIME_PM_OPS(msm_dsi_runtime_suspend, msm_dsi_runtime_resume, NULL) }; diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index 7d985f8..7451ae0 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -1040,6 +1040,7 @@ static int msm_pm_suspend(struct device *dev) { struct drm_device *ddev = dev_get_drvdata(dev); struct msm_drm_private *priv = ddev->dev_private; + struct msm_kms *kms = priv->kms; if (WARN_ON(priv->pm_state)) drm_atomic_state_put(priv->pm_state); @@ -1051,6 +1052,11 @@ static int msm_pm_suspend(struct device *dev) return ret; } + if (kms->funcs->disable_dpu) + kms->funcs->disable_dpu(kms); + + pm_runtime_put_sync(dev); + return 0; } @@ -1069,6 +1075,13 @@ static int msm_pm_resume(struct device *dev) return ret; } + +static int msm_pm_suspend_late(struct device *dev) +{ + pm_runtime_get_noresume(dev); + return 0; +} + #endif #ifdef CONFIG_PM @@ -1102,6 +1115,7 @@ static int msm_runtime_resume(struct device *dev) #endif static const struct dev_pm_ops msm_pm_ops = { + SET_LATE_SYSTEM_SLEEP_PM_OPS(msm_pm_suspend_late, NULL) SET_SYSTEM_SLEEP_PM_OPS(msm_pm_suspend, msm_pm_resume) SET_RUNTIME_PM_OPS(msm_runtime_suspend, msm_runtime_resume, NULL) }; diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h index 1cbef6b..c73a89b 100644 --- a/drivers/gpu/drm/msm/msm_kms.h +++ b/drivers/gpu/drm/msm/msm_kms.h @@ -126,6 +126,8 @@ struct msm_kms_funcs { /* debugfs: */ int (*debugfs_init)(struct msm_kms *kms, struct drm_minor *minor); #endif + void (*disable_dpu)(struct msm_kms *kms); + }; struct msm_kms;
"The PM core always increments the runtime usage counter before calling the ->suspend() callback and decrements it after calling the ->resume() callback" DPU and DSI are managed as runtime devices. When suspend is triggered, PM core adds a refcount on all the devices and calls device suspend, since usage count is already incremented, runtime suspend was not getting called and it kept the clocks on which resulted in target not entering into XO shutdown. Add changes to manage runtime devices during pm sleep. Changes in v1: - Remove unnecessary checks in the function _dpu_kms_disable_dpu (Rob Clark). Signed-off-by: Kalyan Thota <kalyan_t@codeaurora.org> --- drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 28 ++++++++++++++++++++++++++++ drivers/gpu/drm/msm/dsi/dsi.c | 7 +++++++ drivers/gpu/drm/msm/msm_drv.c | 14 ++++++++++++++ drivers/gpu/drm/msm/msm_kms.h | 2 ++ 4 files changed, 51 insertions(+)