xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

drm/vkms: Fix race condition around accessing frame number

Browse Source 
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
This commit is contained in:
Haneen Mohammed
2018-09-04 00:18:17 +03:00
committed by Daniel Vetter
parent 428e15cc41
commit 0ca33adb91
3 changed files with 54 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/gpu/drm/vkms/vkms_crtc.c
View File

@@ -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);