On 2020-03-31 21:30, Doug Anderson wrote:

Hi,

On Tue, Mar 31, 2020 at 6:58 AM 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 force suspend on runtime devices during pm sleep.

Changes in v1:

• Remove unnecessary checks in the function _dpu_kms_disable_dpu (Rob Clark).

Changes in v2:

• Avoid using suspend_late to reset the usagecount as suspend_late might not be called during suspend call failures (Doug).

Changes in v3:

• Use force suspend instead of managing device usage_count via runtime put and get API's to trigger callbacks (Doug).

Signed-off-by: Kalyan Thota kalyan_t@codeaurora.org

drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 2 ++ drivers/gpu/drm/msm/dsi/dsi.c | 2 ++ drivers/gpu/drm/msm/msm_drv.c | 4 ++++ 3 files changed, 8 insertions(+)

This looks much saner to me. Thanks! I assume it still works fine for you? I'm still no expert on how all the pieces of DRM drivers work together, but at least there's not a bunch of strange fiddling with pm_runtime state and hopefully it will avoid weird corner cases...

--- Yes, verified the change on trogdor device, and display can suspend with the change.

...

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c index ce19f1d..b886d9d 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c @@ -1123,6 +1123,8 @@ static int __maybe_unused dpu_runtime_resume(struct device *dev)

static const struct dev_pm_ops dpu_pm_ops = { SET_RUNTIME_PM_OPS(dpu_runtime_suspend, dpu_runtime_resume, NULL)

•   SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
  

•                           pm_runtime_force_resume)
  

};

static const struct of_device_id dpu_dt_match[] = { diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c index 55ea4bc2..62704885 100644 --- a/drivers/gpu/drm/msm/dsi/dsi.c +++ b/drivers/gpu/drm/msm/dsi/dsi.c @@ -161,6 +161,8 @@ static int dsi_dev_remove(struct platform_device *pdev)

static const struct dev_pm_ops dsi_pm_ops = { SET_RUNTIME_PM_OPS(msm_dsi_runtime_suspend, msm_dsi_runtime_resume, NULL)

•   SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
  

•                           pm_runtime_force_resume)
  

};

static struct platform_driver dsi_driver = { diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index 7d985f8..2b8c99c 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -1051,6 +1051,8 @@ static int msm_pm_suspend(struct device *dev) return ret; }

•   pm_runtime_force_suspend(dev);
  

nit: check return value of pm_runtime_force_suspend()?

...

•   return 0;
  

}

@@ -1063,6 +1065,8 @@ static int msm_pm_resume(struct device *dev) if (WARN_ON(!priv->pm_state)) return -ENOENT;

•   pm_runtime_force_resume(dev);
  

nit: check return value of pm_runtime_force_resume()?

-Doug