lkml.org 
[lkml]   [2017]   [Apr]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] drm/vc4: Fix refcounting of runtime PM get if it errors out.
On Mon, Apr 17, 2017 at 09:26:03AM -0700, Eric Anholt wrote:
> We were returning without decrementing if the error happened, meaning
> that at the next submit we wouldn't try to bring up the power domain.
>
> Signed-off-by: Eric Anholt <eric@anholt.net>

This change looks good to me. It seems a little odd to wrap pm_runtime which
is already refcounted in another refcount, but I'm really not familiar with
the driver, and I'm sure there's a good reason for it.

Reviewed-by: Sean Paul <seanpaul@chromium.org>

> ---
>
> I stumbled across this error when testing my CMA patch with a very low
> (64MB) CMA area -- we would oops on the submit after the one that
> failed.
>
> drivers/gpu/drm/vc4/vc4_gem.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
> index 777a8d9afd60..735412e3725a 100644
> --- a/drivers/gpu/drm/vc4/vc4_gem.c
> +++ b/drivers/gpu/drm/vc4/vc4_gem.c
> @@ -1016,13 +1016,16 @@ vc4_submit_cl_ioctl(struct drm_device *dev, void *data,
> }
>
> mutex_lock(&vc4->power_lock);
> - if (vc4->power_refcount++ == 0)
> + if (vc4->power_refcount++ == 0) {
> ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev);
> - mutex_unlock(&vc4->power_lock);
> - if (ret < 0) {
> - kfree(exec);
> - return ret;
> + if (ret < 0) {
> + mutex_unlock(&vc4->power_lock);
> + vc4->power_refcount--;
> + kfree(exec);
> + return ret;
> + }
> }
> + mutex_unlock(&vc4->power_lock);
>
> exec->args = args;
> INIT_LIST_HEAD(&exec->unref_list);
> --
> 2.11.0

--
Sean Paul, Software Engineer, Google / Chromium OS

\
 
 \ /
  Last update: 2017-04-17 19:59    [W:1.030 / U:0.108 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site