On Mon, Sep 11, 2023 at 11:19:13AM +0200, Johan Hovold wrote:
On Fri, Sep 08, 2023 at 08:37:12PM -0400, Sasha Levin wrote:
From: Dan Drown <dan-netdev@xxxxxxxxx>
[ Upstream commit f72ae60881ff685004d7de7152517607fcd9968f ]
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@xxxxxxxxx>
Acked-by: Oliver Neukum <oneukum@xxxxxxxx>
Link: https://lore.kernel.org/r/ZN1zV/zjPgpGlHXo@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/class/cdc-acm.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 11da5fb284d0a..ca51230f44409 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -318,6 +318,16 @@ 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;
This is a fix for a commit in 6.6-rc1 (3b563b901eef ("usb: cdc-acm: add
PPS support")) so a backport of it makes no sense.
Please drop.
Done, thanks!
--
Thanks,
Sasha
