media: apple: isp: Add a missing read barrier (possibly?)

hoshinolina · jannau · commit d7988583ff91 · 2025-06-12T18:38:22.000+02:00
Signed-off-by: Asahi Lina &lt;lina@asahilina.net&gt;
diff --git a/drivers/media/platform/apple/isp/isp-ipc.c b/drivers/media/platform/apple/isp/isp-ipc.c
@@ -157,6 +157,8 @@ int ipc_chan_handle(struct apple_isp *isp, struct isp_channel *chan)
 
 static inline bool chan_tx_done(struct apple_isp *isp, struct isp_channel *chan)
 {
+	dma_rmb();
+
 	chan_read_msg(isp, chan, &chan->rsp);
 	if ((chan->rsp.arg0) == (chan->req.arg0 | ISP_IPC_FLAG_ACK)) {
 		chan_update_cursor(chan);

Original file line number	Diff line number	Diff line change
`@@ -157,6 +157,8 @@ int ipc_chan_handle(struct apple_isp isp, struct isp_channel chan)`
`157`	`157`
`158`	`158`	`static inline bool chan_tx_done(struct apple_isp isp, struct isp_channel chan)`
`159`	`159`	`{`
	`160`	`+ dma_rmb();`
	`161`	`+`
`160`	`162`	`chan_read_msg(isp, chan, &chan->rsp);`
`161`	`163`	`if ((chan->rsp.arg0) == (chan->req.arg0 \| ISP_IPC_FLAG_ACK)) {`
`162`	`164`	`chan_update_cursor(chan);`