6.18-stable review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan@kernel.org
commit b6e0b3016187446ddef9edac03cd9d544ac63f11 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/serial/belkin_sa.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-)
--- 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 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 } 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;