lkml.org 
[lkml]   [2020]   [Mar]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Freedreno] [PATCH] drm/msm/dpu: ensure device suspend happens during PM sleep
On 2020-03-31 00:25, Doug Anderson wrote:
> Hi,
>
> On Mon, Mar 30, 2020 at 2:04 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 manage 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).
>>
>> Signed-off-by: Kalyan Thota <kalyan_t@codeaurora.org>
>> ---
>> drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 33
>> +++++++++++++++++++++++++++++++++
>> drivers/gpu/drm/msm/msm_drv.c | 4 ++++
>> drivers/gpu/drm/msm/msm_kms.h | 2 ++
>> 3 files changed, 39 insertions(+)
>
> I am still 100% baffled by your patch and I never did quite understand
> your response to my previous comments [1]. I think you're saying that
> the problem you were facing is that if you call "suspend" but never
> called "runtime_suspend" that the device stays active. Is that right?
> If that's true, did you try something like this suggestion I made?
>
> SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> pm_runtime_force_resume)
>
>
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> index ce19f1d..2343cbd 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 +326,37 @@ 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);
>> + }
>> + pm_runtime_put_sync(dev->dev);
>> +
>> + /* Increment the usagecount without triggering a resume */
>> + pm_runtime_get_noresume(dev->dev);
>> +
>> + pm_runtime_get_noresume(&dpu_kms->pdev->dev);
>> +
>> + for (i = 0; i < ARRAY_SIZE(priv->dsi); i++) {
>> + if (!priv->dsi[i])
>> + continue;
>> + dsi = priv->dsi[i];
>> + pm_runtime_get_noresume(&dsi->pdev->dev);
>> + }
>> +}
>
> My pm_runtime knowledge is pretty weak sometimes, but the above
> function looks crazy. Maybe it's just me not understanding, but can
> you please summarize what you're trying to accomplish?
>
-- I was trying to get the runtime callbacks via controlling the device
usage_count
Since the usage_count was already incremented by PM core, i was
decrementing and incrementing (without resume)
so that callbacks are triggered.

I have taken your suggestion on forcing the suspend instead of managing
it via usage_count.
i'll follow it up in the next patchset.

> -Doug
>
> [1]
> https://lore.kernel.org/r/114130f68c494f83303c51157e2c5bfa@codeaurora.org
> _______________________________________________
> Freedreno mailing list
> Freedreno@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/freedreno

\
 
 \ /
  Last update: 2020-03-31 16:05    [W:0.126 / U:4.272 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site