Commit f72ae608 authored by Dan Drown's avatar Dan Drown Committed by Greg Kroah-Hartman
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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: default avatarDan Drown <dan-netdev@drown.org>
Acked-by: default avatarOliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/ZN1zV/zjPgpGlHXo@vps3.drown.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 23e60c8d

drivers/usb/class/cdc-acm.c

+11 −10
Original line number Diff line number Diff line
@@ -319,14 +319,8 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf) 
		}



		difference = acm->ctrlin ^ newctrl;

		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) {

		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)
@@ -334,8 +328,15 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf) 
				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)

			acm->iocount.dcd++;

		}

		if (newctrl & USB_CDC_SERIAL_STATE_BREAK) {

			acm->iocount.brk++;

			tty_insert_flip_char(&acm->port, 0, TTY_BREAK);