diff options
| author | Johan Hovold <johan@kernel.org> | 2025-10-22 18:26:33 +0300 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2025-10-27 11:21:26 +0300 |
| commit | b6e0b3016187446ddef9edac03cd9d544ac63f11 (patch) | |
| tree | 69b51da51e6d0163c0e8adb883d992ba0a9380fb | |
| parent | dcb6fa37fd7bc9c3d2b066329b0d27dedf8becaa (diff) | |
| download | linux-b6e0b3016187446ddef9edac03cd9d544ac63f11.tar.xz | |
USB: serial: belkin_sa: fix TIOCMBIS and TIOCMBIC
Asserting or deasserting a modem control line using TIOCMBIS or TIOCMBIC
should not deassert any lines that are not in the mask.
Fix this long-standing regression dating back to 2003 when the
tiocmset() callback was introduced.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
| -rw-r--r-- | drivers/usb/serial/belkin_sa.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/drivers/usb/serial/belkin_sa.c b/drivers/usb/serial/belkin_sa.c index 44f5b58beec9..aa6b4c4ad5ec 100644 --- a/drivers/usb/serial/belkin_sa.c +++ b/drivers/usb/serial/belkin_sa.c @@ -435,7 +435,7 @@ static int belkin_sa_tiocmset(struct tty_struct *tty, struct belkin_sa_private *priv = usb_get_serial_port_data(port); unsigned long control_state; unsigned long flags; - int retval; + int retval = 0; int rts = 0; int dtr = 0; @@ -452,26 +452,32 @@ static int belkin_sa_tiocmset(struct tty_struct *tty, } if (clear & TIOCM_RTS) { control_state &= ~TIOCM_RTS; - rts = 0; + rts = 1; } if (clear & TIOCM_DTR) { control_state &= ~TIOCM_DTR; - dtr = 0; + dtr = 1; } priv->control_state = control_state; spin_unlock_irqrestore(&priv->lock, flags); - retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts); - if (retval < 0) { - dev_err(&port->dev, "Set RTS error %d\n", retval); - goto exit; + if (rts) { + retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, + !!(control_state & TIOCM_RTS)); + if (retval < 0) { + dev_err(&port->dev, "Set RTS error %d\n", retval); + goto exit; + } } - retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr); - if (retval < 0) { - dev_err(&port->dev, "Set DTR error %d\n", retval); - goto exit; + if (dtr) { + retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, + !!(control_state & TIOCM_DTR)); + if (retval < 0) { + dev_err(&port->dev, "Set DTR error %d\n", retval); + goto exit; + } } exit: return retval; |