[PATCH v6 07/12] media: mediatek: jpeg: fix decoding resolution change operation

[Kyrie Wu <kyrie.wu@mediatek.com>]

1.add a judgement for src buffer to avoid kernel crash
in the stop streaming function;
2.When a resolution changing occurs, it needs to set new
resolution parameter immediately and then report this event.
Otherwise, if the original software process is maintained,
the resolution change event is reported firstly, the CPU is
dispatched to the app to process the event, and the driver
does not set a new resolution, which will cause parameter errors.
3.After a resolution change occurred, decoding should not continue,
needs to wait until new buffers are ready and the state machine
changed.

Fixes: dedc21500334 ("media: mtk-jpegdec: add jpeg decode worker interface")
Signed-off-by: Kyrie Wu <kyrie.wu@mediatek.com>
---
 drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
index 3fc344d05528..e8d11fb3d330 100644
--- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
+++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
@@ -887,7 +887,8 @@ static void mtk_jpeg_dec_stop_streaming(struct vb2_queue *q)
 
 		vb = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
 		src_buf = mtk_jpeg_vb2_to_srcbuf(&vb->vb2_buf);
-		mtk_jpeg_set_queue_data(ctx, &src_buf->dec_param);
+		if (!IS_ERR_OR_NULL(src_buf))
+			mtk_jpeg_set_queue_data(ctx, &src_buf->dec_param);
 		ctx->state = MTK_JPEG_RUNNING;
 	} else if (V4L2_TYPE_IS_OUTPUT(q->type)) {
 		ctx->state = MTK_JPEG_INIT;
@@ -1750,11 +1751,15 @@ static void mtk_jpegdec_worker(struct work_struct *work)
 
 	if (mtk_jpeg_check_resolution_change(ctx,
 					     &jpeg_src_buf->dec_param)) {
-		mtk_jpeg_queue_src_chg_event(ctx);
+		mtk_jpeg_set_queue_data(ctx, &jpeg_src_buf->dec_param);
 		ctx->state = MTK_JPEG_SOURCE_CHANGE;
+		mtk_jpeg_queue_src_chg_event(ctx);
 		goto getbuf_fail;
 	}
 
+	if (ctx->state == MTK_JPEG_SOURCE_CHANGE)
+		goto getbuf_fail;
+
 	mtk_jpegdec_set_hw_param(ctx, hw_id, src_buf, dst_buf);
 	ret = pm_runtime_resume_and_get(comp_jpeg[hw_id]->dev);
 	if (ret < 0) {
-- 
2.46.0