[PATCH v2 1/2] 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() returns without holding
a runtime PM usage reference. The unconditional
pm_runtime_put_autosuspend() at the end of the function then drops an
unmatched reference.

The failed resume path can also continue into
wave5_vpu_dec_clr_disp_flag() while the device is still suspended.

Check the return value. 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