From: Zack Rusin zackr@vmware.com
By default each flip times out after 0.1 sec and a warning about the time out is added to the kernel log. The warning is harmless because there's another flip coming right after but it can quickly fill up the log, e.g. missing 2 flips every second over a 24 hour span will add about 172 thousand lines to the log. Skip printing it by default and instead add it to the atomic drm debug category. It can be trivially enabled via drm.debug=0x10 and it avoids filling up logs by default.
This is particularly important on vm's where presentation might be CPU bound and running multiple vm's or under a CPU heavy load can easily lead to missing mutliple flips and any actual errors are often blamed on this due to it being so prevalent in the logs. Fixes a bunch of bugs reported to RedHat (1792515, 1884401, 1896139 and 1884401) and SUSE (210123) where people complain about having their logs spammed by this message and blame various errors on it.
Signed-off-by: Zack Rusin zackr@vmware.com --- drivers/gpu/drm/drm_atomic_helper.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 9603193d2fa1..e88b4d83fd5c 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1566,8 +1566,8 @@ void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev,
ret = wait_for_completion_timeout(&commit->flip_done, 10 * HZ); if (ret == 0) - drm_err(dev, "[CRTC:%d:%s] flip_done timed out\n", - crtc->base.id, crtc->name); + drm_dbg_atomic(dev, "[CRTC:%d:%s] flip_done timed out\n", + crtc->base.id, crtc->name); }
if (old_state->fake_commit)