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| author | Haneen Mohammed <hamohammed.sa@gmail.com> | 2018-09-04 00:18:17 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2018-09-05 17:04:50 +0300 |
| commit | 0ca33adb91c0a94a29bdcecf49cd08fe24a21666 (patch) | |
| tree | e487af079a4fd29add813e801f9afcc3f0f2d37f /drivers/gpu/drm/vkms/vkms_crtc.c | |
| parent | 428e15cc41e3603942edd4a1aa991127ce9eccea (diff) | |
| download | linux-0ca33adb91c0a94a29bdcecf49cd08fe24a21666.tar.xz | |
drm/vkms: Fix race condition around accessing frame number
crtc_state is accessed by both vblank_handle() and the ordered
work_struct handle vkms_crc_work_handle() to retrieve and or update
the frame number for computed CRC.
Since work_struct can fail, add frame_end to account for missing frame
numbers.
Use (frame_[start/end]) for synchronization between hrtimer callback
and ordered work_struct handle.
This patch passes the following subtests from igt kms_pipe_crc_basic test:
bad-source, read-crc-pipe-A, read-crc-pipe-A-frame-sequence,
nonblocking-crc-pipe-A, nonblocking-crc-pipe-A-frame-sequence
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180903211743.GA2773@haneenDRM
Diffstat (limited to 'drivers/gpu/drm/vkms/vkms_crtc.c')
| -rw-r--r-- | drivers/gpu/drm/vkms/vkms_crtc.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c index 9d0b1a325a78..177bbcb38306 100644 --- a/drivers/gpu/drm/vkms/vkms_crtc.c +++ b/drivers/gpu/drm/vkms/vkms_crtc.c @@ -22,8 +22,19 @@ static void _vblank_handle(struct vkms_output *output) DRM_ERROR("vkms failure on handling vblank"); if (state && output->crc_enabled) { - state->n_frame = drm_crtc_accurate_vblank_count(crtc); - queue_work(output->crc_workq, &state->crc_work); + u64 frame = drm_crtc_accurate_vblank_count(crtc); + + /* update frame_start only if a queued vkms_crc_work_handle() + * has read the data + */ + spin_lock(&output->state_lock); + if (!state->frame_start) + state->frame_start = frame; + spin_unlock(&output->state_lock); + + ret = queue_work(output->crc_workq, &state->crc_work); + if (!ret) + DRM_WARN("failed to queue vkms_crc_work_handle"); } spin_unlock(&output->lock); @@ -211,6 +222,7 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc, drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs); spin_lock_init(&vkms_out->lock); + spin_lock_init(&vkms_out->state_lock); vkms_out->crc_workq = alloc_ordered_workqueue("vkms_crc_workq", 0); |