[PATCH] drm/kms/plane: Avoiding redundant checks in case of EDEADLK retries
From: Satendra Singh Thakur
Date: Mon Jul 30 2018 - 01:55:39 EST
1. Currently, if modeset_lock is re-tried many times in case of EDEADLK
error, then this will be the code flow
retry:
ret = drm_modeset_lock();
if (ret)-->this is true
goto out;
out:
if (fb)
if (plane->old_fb)
if (ret == -EDEADLK)
goto retry;
It can be observed that checks on fb, old_fb are redundant
in retry-case.
If we keep if (ret == -EDEADLK) right after the out label,
that will avoid redundant checks.
It won't affect normal scenario (non-retry case).
2. Moved NULL assignment inside if statement related to NULL check
Signed-off-by: Satendra Singh Thakur <satendra.t@xxxxxxxxxxx>
---
drivers/gpu/drm/drm_plane.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 0350544..ed42cd4 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -658,9 +658,10 @@ static int __setplane_internal(struct drm_plane *plane,
}
out:
- if (plane->old_fb)
+ if (plane->old_fb) {
drm_framebuffer_put(plane->old_fb);
- plane->old_fb = NULL;
+ plane->old_fb = NULL;
+ }
return ret;
}
@@ -1097,17 +1098,17 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
}
out:
- if (fb)
- drm_framebuffer_put(fb);
- if (plane->old_fb)
- drm_framebuffer_put(plane->old_fb);
- plane->old_fb = NULL;
-
if (ret == -EDEADLK) {
ret = drm_modeset_backoff(&ctx);
if (!ret)
goto retry;
}
+ if (fb)
+ drm_framebuffer_put(fb);
+ if (plane->old_fb) {
+ drm_framebuffer_put(plane->old_fb);
+ plane->old_fb = NULL;
+ }
drm_modeset_drop_locks(&ctx);
drm_modeset_acquire_fini(&ctx);
--
2.7.4