iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

USB: serial: keyspan_pda: fix dropped unthrottle interrupts

Browse Source 
commit 696c541c8c6cfa05d65aa24ae2b9e720fc01766e upstream.

Commit c528fcb116e6 ("USB: serial: keyspan_pda: fix receive sanity
checks") broke write-unthrottle handling by dropping well-formed
unthrottle-interrupt packets which are precisely two bytes long. This
could lead to blocked writers not being woken up when buffer space again
becomes available.

Instead, stop unconditionally printing the third byte which is
(presumably) only valid on modem-line changes.

Fixes: c528fcb116e6 ("USB: serial: keyspan_pda: fix receive sanity checks")
Cc: stable <stable@vger.kernel.org>     # 4.11
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2020-10-25 18:45:47 +01:00 committed by Greg Kroah-Hartman
parent 272c6a678e
commit 2437205038
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/usb/serial/keyspan_pda.c
View File

@ -172,11 +172,11 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)
break;
case 1:
/* status interrupt */
if (len < 3) {
if (len < 2) {
dev_warn(&port->dev, "short interrupt message received\n");
break;
}
dev_dbg(&port->dev, "rx int, d1=%d, d2=%d\n", data[1], data[2]);
dev_dbg(&port->dev, "rx int, d1=%d\n", data[1]);
switch (data[1]) {
case 1: /* modemline change */
break;