media: apple: isp: Use a mutex instead of a spinlock for channels

Fixes lockdep splats because we do surface stuff with this held, which
takes a mutex.

Signed-off-by: Hector Martin <marcan@marcan.st>

Author: marcan

drivers/media/platform/apple/isp/isp-drv.h

@@ -76,7 +76,7 @@ struct isp_channel {
 	void *virt;
 	u32 doorbell;
 	u32 cursor;
-	spinlock_t lock;
+	struct mutex lock;
 	struct isp_message req;
 	struct isp_message rsp;
 	const struct isp_chan_ops *ops;

drivers/media/platform/apple/isp/isp-fw.c

@@ -491,7 +491,7 @@ static int isp_fill_channel_info(struct apple_isp *isp)
 		chan->virt =
 			apple_isp_ipc_translate(isp, desc.iova, chan->size);
 		chan->cursor = 0;
-		spin_lock_init(&chan->lock);
+		mutex_init(&chan->lock);
 
 		if (!chan->virt) {
 			dev_err(isp->dev, "Failed to find channel buffer\n");

drivers/media/platform/apple/isp/isp-ipc.c

@@ -138,7 +138,7 @@ int ipc_chan_handle(struct apple_isp *isp, struct isp_channel *chan)
 {
 	int err = 0;
 
-	spin_lock(&chan->lock);
+	mutex_lock(&chan->lock);
 	while (1) {
 		chan_read_msg(isp, chan, &chan->req);
 		if (chan_rx_done(isp, chan)) {
@@ -150,7 +150,7 @@ int ipc_chan_handle(struct apple_isp *isp, struct isp_channel *chan)
 			break;
 		}
 	}
-	spin_unlock(&chan->lock);
+	mutex_unlock(&chan->lock);
 
 	return err;
 }