From: Tetsuo Handa Date: Thu, 17 Jul 2025 16:04:00 +0000 (+0900) Subject: media: imon: grab lock earlier in imon_ir_change_protocol() X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7019553ab850ce1d3f0e512e16d14ab153f91c04;p=users%2Fhch%2Fmisc.git media: imon: grab lock earlier in imon_ir_change_protocol() Move mutex_trylock() in imon_ir_change_protocol() to the beginning, for memcpy() which modifies ictx->usb_tx_buf should be protected by ictx->lock. Also, verify at the beginning of send_packet() that ictx->lock is held in case send_packet() is by error called from imon_ir_change_protocol() when mutex_trylock() failed due to concurrent requests. Signed-off-by: Tetsuo Handa Signed-off-by: Sean Young Signed-off-by: Hans Verkuil --- diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c index b914dd39c21c..8275ca5e9b6f 100644 --- a/drivers/media/rc/imon.c +++ b/drivers/media/rc/imon.c @@ -598,6 +598,8 @@ static int send_packet(struct imon_context *ictx) int retval = 0; struct usb_ctrlrequest *control_req = NULL; + lockdep_assert_held(&ictx->lock); + /* Check if we need to use control or interrupt urb */ if (!ictx->tx_control) { pipe = usb_sndintpipe(ictx->usbdev_intf0, @@ -1124,7 +1126,7 @@ static int imon_ir_change_protocol(struct rc_dev *rc, u64 *rc_proto) int retval; struct imon_context *ictx = rc->priv; struct device *dev = ictx->dev; - bool unlock = false; + const bool unlock = mutex_trylock(&ictx->lock); unsigned char ir_proto_packet[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x86 }; @@ -1151,8 +1153,6 @@ static int imon_ir_change_protocol(struct rc_dev *rc, u64 *rc_proto) memcpy(ictx->usb_tx_buf, &ir_proto_packet, sizeof(ir_proto_packet)); - unlock = mutex_trylock(&ictx->lock); - retval = send_packet(ictx); if (retval) goto out;