[PATCH] media: chips-media: wave5: Check decoder qbuf runtime resume

[Guangshuo Li]

wave5_vpu_dec_buf_queue_dst() resumes the VPU before it may clear a
decoder display flag. This is needed because clearing the display flag
accesses VPU registers.

However, the return value from pm_runtime_resume_and_get() is ignored.
If the resume fails, pm_runtime_resume_and_get() has already dropped the
runtime PM usage count it acquired before returning the error. The
unconditional pm_runtime_put_autosuspend() at the end of the function
then drops the usage count again.

The failed resume path can also continue into
wave5_vpu_dec_clr_disp_flag() while the device is still suspended,
reopening the powered-off register access that the runtime PM get was
meant to prevent.

Check the return value from pm_runtime_resume_and_get(). If the resume
fails, complete the queued buffer with an error and return without
touching the hardware or dropping an unmatched runtime PM reference.

Fixes: cbb9c0d50e47 ("media: chips-media: wave5: Fix SError of kernel panic when closed")
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
index bb2ba9204a83..03d108b808ba 100644
--- a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
+++ b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
@@ -1290,8 +1290,14 @@ static void wave5_vpu_dec_buf_queue_dst(struct vb2_buffer *vb)
 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 	struct vpu_instance *inst = vb2_get_drv_priv(vb->vb2_queue);
 	struct v4l2_m2m_ctx *m2m_ctx = inst->v4l2_fh.m2m_ctx;
+	int ret;
+
+	ret = pm_runtime_resume_and_get(inst->dev->dev);
+	if (ret < 0) {
+		vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
+		return;
+	}
 
-	pm_runtime_resume_and_get(inst->dev->dev);
 	vbuf->sequence = inst->queued_dst_buf_num++;
 
 	if (inst->state == VPU_INST_STATE_PIC_RUN) {
-- 
2.43.0