On 07/10/2025 16:01, Adrián Larumbe wrote:
> If we reach the beginning of the LRU AS list, then return an error.
>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Very much "should never happen", but I guess adding error handling can't
hurt ;)
One minor NIT below, but either way:
Reviewed-by: Steven Price <steven.price@arm.com>
> ---
> drivers/gpu/drm/panfrost/panfrost_job.c | 6 +++++-
> drivers/gpu/drm/panfrost/panfrost_mmu.c | 5 +++--
> drivers/gpu/drm/panfrost/panfrost_mmu.h | 2 +-
> drivers/gpu/drm/panfrost/panfrost_perfcnt.c | 9 ++++++++-
> 4 files changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index ea3f2878fd15..1b3af5d52081 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -213,7 +213,11 @@ static int panfrost_job_hw_submit(struct panfrost_job *job, int js)
> goto err_hwsubmit;
> }
>
> - cfg = panfrost_mmu_as_get(pfdev, job->mmu);
> + ret = panfrost_mmu_as_get(pfdev, job->mmu);
> + if (ret < 0)
> + goto err_hwsubmit;
> +
> + cfg = ret;
>
> panfrost_devfreq_record_busy(&pfdev->pfdevfreq);
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index 1d696eeea2fa..cf272b167feb 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> @@ -258,7 +258,7 @@ static int panfrost_mmu_cfg_init(struct panfrost_mmu *mmu,
> }
> }
>
> -u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
> +int panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
> {
> int as;
>
> @@ -300,7 +300,8 @@ u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
> if (!atomic_read(&lru_mmu->as_count))
> break;
> }
> - WARN_ON(&lru_mmu->list == &pfdev->as_lru_list);
> + if (WARN_ON(&lru_mmu->list == &pfdev->as_lru_list))
> + return -EBUSY;
>
> list_del_init(&lru_mmu->list);
> as = lru_mmu->as;
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.h b/drivers/gpu/drm/panfrost/panfrost_mmu.h
> index 022a9a74a114..e6e6966a0cca 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.h
> @@ -16,7 +16,7 @@ void panfrost_mmu_fini(struct panfrost_device *pfdev);
> void panfrost_mmu_reset(struct panfrost_device *pfdev);
> void panfrost_mmu_suspend_irq(struct panfrost_device *pfdev);
>
> -u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu);
> +int panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu);
> void panfrost_mmu_as_put(struct panfrost_device *pfdev, struct panfrost_mmu *mmu);
>
> struct panfrost_mmu *panfrost_mmu_ctx_get(struct panfrost_mmu *mmu);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
> index 718eb44b40f8..a8d821e1bde2 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
> @@ -132,7 +132,12 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
>
> perfcnt->user = user;
NIT: If we just move this line below the call to panfrost_mmu_as_get()
then we don't need the extra label and the special error handling.
Thanks,
Steve
>
> - as = panfrost_mmu_as_get(pfdev, perfcnt->mapping->mmu);
> + ret = panfrost_mmu_as_get(pfdev, perfcnt->mapping->mmu);
> + if (ret < 0)
> + goto err_unsetuser;
> +
> + as = ret;
> +
> cfg = GPU_PERFCNT_CFG_AS(as) |
> GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_MANUAL);
>
> @@ -166,6 +171,8 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
>
> return 0;
>
> +err_unsetuser:
> + perfcnt->user = NULL;
> err_vunmap:
> drm_gem_vunmap(&bo->base, &map);
> err_put_mapping: