From ebd9857a5bd40fe80c6d80c0c3618a2f43acbb01 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sun, 25 Oct 2020 18:45:47 +0100 Subject: USB: serial: keyspan_pda: fix dropped unthrottle interrupts 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 # 4.11 Acked-by: Sebastian Andrzej Siewior Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/keyspan_pda.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/usb') diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c index bf988f77d400..f4cd2085b2c1 100644 --- a/drivers/usb/serial/keyspan_pda.c +++ b/drivers/usb/serial/keyspan_pda.c @@ -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; -- cgit v1.2.3