diff options
author | Sam Ravnborg <sam@ravnborg.org> | 2019-07-27 00:06:58 +0300 |
---|---|---|
committer | Sam Ravnborg <sam@ravnborg.org> | 2019-08-03 17:07:39 +0300 |
commit | 05103ea9a3159b9bb7004e9c0693948d4d6124f9 (patch) | |
tree | 0222fb2a74aeec45b5723f6869942165321ff320 | |
parent | d6781e490179f7ba710dd924187109da70c185b0 (diff) | |
download | linux-05103ea9a3159b9bb7004e9c0693948d4d6124f9.tar.xz |
drm/vblank: drop use of DRM_WAIT_ON()
DRM_WAIT_ON() is from the deprecated drm_os_linux header and
the modern replacement is the wait_event_*.
The return values differ, so a conversion is needed to
keep the original interface towards userspace.
Introduced a switch/case to make code obvious.
Analysis from Michel Dänzer:
The waiting condition rely on all relevant places where vblank_count
is modified calls wake_up(&vblank->queue).
drm_handle_vblank():
- Calls wake_up(&vblank->queue)
drm_vblank_enable():
- There is no need here because there can be no sleeping waiters
in the queue, because vblank->enabled == false immediately
terminates any waits.
drm_crtc_accurate_vblank_count():
- This is called from interrupt handlers, at least from
amdgpu_dm.c:dm_pflip_high_irq(). Not sure it needs to wake up
the queue though, the driver should call
drm_(crtc_)_handle_vblank anyway.
drm_vblank_disable_and_save():
- It can be called from an interrupt, via drm_handle_vblank ->
vblank_disable_fn. However, the only place where
drm_vblank_disable_and_save can be called with sleeping waiters
in the queue is in drm_crtc_vblank_off, which wakes up the queue
afterwards (which terminates all waits, because
vblank->enabled == false at this point).
v3:
- Added analysis to changelog from Michel Dänzer
- Moved return result handling inside if (req_seq != seq) (Daniel V)
- Reused more of the former logic - resulting in simpler code
- Dropped Reviewed-by from Sean Paul as this is a new implementation
v2:
- Fix so the case where req_seq equals seq was handled properly
- quick hack to check if IGT became happy
- Only sent to igt, not to dri-devel
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190726210658.GA6299@ravnborg.org
-rw-r--r-- | drivers/gpu/drm/drm_vblank.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 603ab105125d..fd1fbc77871f 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -31,7 +31,6 @@ #include <drm/drm_drv.h> #include <drm/drm_framebuffer.h> #include <drm/drm_print.h> -#include <drm/drm_os_linux.h> #include <drm/drm_vblank.h> #include "drm_internal.h" @@ -1670,12 +1669,28 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data, } if (req_seq != seq) { + int wait; + DRM_DEBUG("waiting on vblank count %llu, crtc %u\n", req_seq, pipe); - DRM_WAIT_ON(ret, vblank->queue, 3 * HZ, - vblank_passed(drm_vblank_count(dev, pipe), - req_seq) || - !READ_ONCE(vblank->enabled)); + wait = wait_event_interruptible_timeout(vblank->queue, + vblank_passed(drm_vblank_count(dev, pipe), req_seq) || + !READ_ONCE(vblank->enabled), + msecs_to_jiffies(3000)); + + switch (wait) { + case 0: + /* timeout */ + ret = -EBUSY; + break; + case -ERESTARTSYS: + /* interrupted by signal */ + ret = -EINTR; + break; + default: + ret = 0; + break; + } } if (ret != -EINTR) { |