[PATCH v3] media: mediatek: jpeg: retry HW selection after successful wait

wait_event_interruptible_timeout() returns a positive value when its
condition becomes true before the timeout. mtk_jpegdec_worker() treats
every nonzero result as a failure, so a normal decoder wakeup finishes
the mem2mem job as though no hardware became available.

Handle interrupted waits and exhausted timeout retries separately, and
retry hardware selection after a successful wakeup. Increment the retry
count only for actual timeouts. The encoder uses
wait_event_interruptible(), whose successful return is zero, so its
existing check is correct; leave that separate no-timeout policy
unchanged.

Fixes: dedc21500334 ("media: mtk-jpegdec: add jpeg decode worker interface")
Assisted-by: Codex:gpt-5
Signed-off-by: Pengpeng Hou <[email protected]>
---
Changes since v2:
https://lore.kernel.org/all/[email protected]/
- add the Fixes tag
- revalidate the decoder-only change against current mainline
- add the required coding-assistant attribution

Changes since v1:
https://lore.kernel.org/all/[email protected]/
- split interrupted waits, timeout exhaustion and successful wakeups
- use distinct diagnostics and explain why the encoder path is unchanged

 drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
index d147ec483081..9634c95aaada 100644
--- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
+++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
@@ -1697,9 +1697,15 @@ static void mtk_jpegdec_worker(struct work_struct *work)
 		ret = wait_event_interruptible_timeout(jpeg->hw_wq,
 						       atomic_read(&jpeg->hw_rdy) > 0,
 						       MTK_JPEG_HW_TIMEOUT_MSEC);
-		if (ret != 0 || (i++ > MTK_JPEG_MAX_RETRY_TIME)) {
-			dev_err(jpeg->dev, "%s : %d, all HW are busy\n",
-				__func__, __LINE__);
+		if (ret < 0) {
+			dev_err(jpeg->dev, "decoder HW wait interrupted: %d\n",
+				ret);
+			v4l2_m2m_job_finish(jpeg->m2m_dev, ctx->fh.m2m_ctx);
+			return;
+		}
+
+		if (!ret && i++ > MTK_JPEG_MAX_RETRY_TIME) {
+			dev_err(jpeg->dev, "all decoder HW are busy\n");
 			v4l2_m2m_job_finish(jpeg->m2m_dev, ctx->fh.m2m_ctx);
 			return;
 		}

base-commit: dac3e89a2c90c2feeb471e1f22a2512ad424b792
-- 
2.50.1 (Apple Git-155)