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authorDan Drown <dan-netdev@drown.org>2023-08-16 20:09:43 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-08-22 14:45:02 +0200
commitf72ae60881ff685004d7de7152517607fcd9968f (patch)
tree49862cbd69a3d128534af6eb5d3fd25ba91e3283
parent23e60c8daf5ec2ab1b731310761b668745fcf6ed (diff)
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usb: cdc-acm: move ldisc dcd notification outside of acm's read lock
dcd_change notification call moved outside of the acm->read_lock to protect any future tty ldisc that calls wait_serial_change() Signed-off-by: Dan Drown <dan-netdev@drown.org> Acked-by: Oliver Neukum <oneukum@suse.com> Link: https://lore.kernel.org/r/ZN1zV/zjPgpGlHXo@vps3.drown.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/class/cdc-acm.c21
1 files changed, 11 insertions, 10 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 9b34199474c4..dfb28c7c3069 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -319,23 +319,24 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf)
}
difference = acm->ctrlin ^ newctrl;
+
+ if ((difference & USB_CDC_SERIAL_STATE_DCD) && acm->port.tty) {
+ struct tty_ldisc *ld = tty_ldisc_ref(acm->port.tty);
+ if (ld) {
+ if (ld->ops->dcd_change)
+ ld->ops->dcd_change(acm->port.tty, newctrl & USB_CDC_SERIAL_STATE_DCD);
+ tty_ldisc_deref(ld);
+ }
+ }
+
spin_lock_irqsave(&acm->read_lock, flags);
acm->ctrlin = newctrl;
acm->oldcount = acm->iocount;
if (difference & USB_CDC_SERIAL_STATE_DSR)
acm->iocount.dsr++;
- if (difference & USB_CDC_SERIAL_STATE_DCD) {
- if (acm->port.tty) {
- struct tty_ldisc *ld = tty_ldisc_ref(acm->port.tty);
- if (ld) {
- if (ld->ops->dcd_change)
- ld->ops->dcd_change(acm->port.tty, newctrl & USB_CDC_SERIAL_STATE_DCD);
- tty_ldisc_deref(ld);
- }
- }
+ if (difference & USB_CDC_SERIAL_STATE_DCD)
acm->iocount.dcd++;
- }
if (newctrl & USB_CDC_SERIAL_STATE_BREAK) {
acm->iocount.brk++;
tty_insert_flip_char(&acm->port, 0, TTY_BREAK);