2020-08-13 18:56:44

by Jonathan Marek

Subject: [RESEND PATCH] drm/msm/a6xx: fix frequency not always being restored on GMU resume

The patch reorganizing the set_freq function made it so the gmu resume
doesn't always set the frequency, because a6xx_gmu_set_freq() exits early
when the frequency hasn't been changed. Note this always happens when
resuming GMU after recovering from a hang.

Use a simple workaround to prevent this from happening.

Fixes: 1f60d11423db ("drm: msm: a6xx: send opp instead of a frequency")

Signed-off-by: Jonathan Marek <[email protected]>
---
drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index b67b38c8fadf..bbbd00020f92 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -845,6 +845,7 @@ static void a6xx_gmu_set_initial_freq(struct msm_gpu *gpu, struct a6xx_gmu *gmu)
if (IS_ERR_OR_NULL(gpu_opp))
return;

+ gmu->freq = 0; /* so a6xx_gmu_set_freq() doesn't exit early */
a6xx_gmu_set_freq(gpu, gpu_opp);
dev_pm_opp_put(gpu_opp);
}
--
2.26.1

2020-08-17 12:54:16

by Akhil P Oommen

Subject: Re: [RESEND PATCH] drm/msm/a6xx: fix frequency not always being restored on GMU resume

Why don't we move the early return in a6xx_gmu_set_freq() to
msm_devfreq_target() instead?

-Akhil.

On 8/14/2020 12:24 AM, Jonathan Marek wrote:
> The patch reorganizing the set_freq function made it so the gmu resume
> doesn't always set the frequency, because a6xx_gmu_set_freq() exits early
> when the frequency hasn't been changed. Note this always happens when
> resuming GMU after recovering from a hang.
>
> Use a simple workaround to prevent this from happening.
>
> Fixes: 1f60d11423db ("drm: msm: a6xx: send opp instead of a frequency")
>
> Signed-off-by: Jonathan Marek <[email protected]>
> ---
> drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> index b67b38c8fadf..bbbd00020f92 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> @@ -845,6 +845,7 @@ static void a6xx_gmu_set_initial_freq(struct msm_gpu *gpu, struct a6xx_gmu *gmu)
> if (IS_ERR_OR_NULL(gpu_opp))
> return;
>
> + gmu->freq = 0; /* so a6xx_gmu_set_freq() doesn't exit early */
> a6xx_gmu_set_freq(gpu, gpu_opp);
> dev_pm_opp_put(gpu_opp);
> }
>