This is a note to let you know that I've just added the patch titled cdc-acm: correct counting of UART states in serial state notification to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cdc-acm-correct-counting-of-uart-states-in-serial-state-notification.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f976d0e5747ca65ccd0fb2a4118b193d70aa1836 Mon Sep 17 00:00:00 2001 From: Tobias Herzog <t-herzog@xxxxxx> Date: Sat, 22 Sep 2018 22:11:11 +0200 Subject: cdc-acm: correct counting of UART states in serial state notification From: Tobias Herzog <t-herzog@xxxxxx> commit f976d0e5747ca65ccd0fb2a4118b193d70aa1836 upstream. The usb standard ("Universal Serial Bus Class Definitions for Communication Devices") distiguishes between "consistent signals" (DSR, DCD), and "irregular signals" (break, ring, parity error, framing error, overrun). The bits of "irregular signals" are set, if this error/event occurred on the device side and are immeadeatly unset, if the serial state notification was sent. Like other drivers of real serial ports do, just the occurence of those events should be counted in serial_icounter_struct (but no 1->0 transitions). Signed-off-by: Tobias Herzog <t-herzog@xxxxxx> Acked-by: Oliver Neukum <oneukum@xxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-acm.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -332,17 +332,17 @@ static void acm_ctrl_irq(struct urb *urb if (difference & ACM_CTRL_DSR) acm->iocount.dsr++; - if (difference & ACM_CTRL_BRK) - acm->iocount.brk++; - if (difference & ACM_CTRL_RI) - acm->iocount.rng++; if (difference & ACM_CTRL_DCD) acm->iocount.dcd++; - if (difference & ACM_CTRL_FRAMING) + if (newctrl & ACM_CTRL_BRK) + acm->iocount.brk++; + if (newctrl & ACM_CTRL_RI) + acm->iocount.rng++; + if (newctrl & ACM_CTRL_FRAMING) acm->iocount.frame++; - if (difference & ACM_CTRL_PARITY) + if (newctrl & ACM_CTRL_PARITY) acm->iocount.parity++; - if (difference & ACM_CTRL_OVERRUN) + if (newctrl & ACM_CTRL_OVERRUN) acm->iocount.overrun++; spin_unlock(&acm->read_lock); Patches currently in stable-queue which might be from t-herzog@xxxxxx are queue-4.4/cdc-acm-correct-counting-of-uart-states-in-serial-state-notification.patch