From d432df758f92c4c28aac409bc807fd1716167577 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 22 Oct 2025 17:26:34 +0200 Subject: [PATCH] USB: serial: kobil_sct: 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 issue dating back to 2003 when the support for these ioctls was added with the introduction of the tiocmset() callback. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold --- drivers/usb/serial/kobil_sct.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/usb/serial/kobil_sct.c b/drivers/usb/serial/kobil_sct.c index 464433be20344..96ea571c436a7 100644 --- a/drivers/usb/serial/kobil_sct.c +++ b/drivers/usb/serial/kobil_sct.c @@ -418,7 +418,7 @@ static int kobil_tiocmset(struct tty_struct *tty, struct usb_serial_port *port = tty->driver_data; struct device *dev = &port->dev; struct kobil_private *priv; - int result; + int result = 0; int dtr = 0; int rts = 0; @@ -435,12 +435,12 @@ static int kobil_tiocmset(struct tty_struct *tty, if (set & TIOCM_DTR) dtr = 1; if (clear & TIOCM_RTS) - rts = 0; + rts = 1; if (clear & TIOCM_DTR) - dtr = 0; + dtr = 1; - if (priv->device_type == KOBIL_ADAPTER_B_PRODUCT_ID) { - if (dtr != 0) + if (dtr && priv->device_type == KOBIL_ADAPTER_B_PRODUCT_ID) { + if (set & TIOCM_DTR) dev_dbg(dev, "%s - Setting DTR\n", __func__); else dev_dbg(dev, "%s - Clearing DTR\n", __func__); @@ -448,13 +448,13 @@ static int kobil_tiocmset(struct tty_struct *tty, usb_sndctrlpipe(port->serial->dev, 0), SUSBCRequest_SetStatusLinesOrQueues, USB_TYPE_VENDOR | USB_RECIP_ENDPOINT | USB_DIR_OUT, - ((dtr != 0) ? SUSBCR_SSL_SETDTR : SUSBCR_SSL_CLRDTR), + ((set & TIOCM_DTR) ? SUSBCR_SSL_SETDTR : SUSBCR_SSL_CLRDTR), 0, NULL, 0, KOBIL_TIMEOUT); - } else { - if (rts != 0) + } else if (rts) { + if (set & TIOCM_RTS) dev_dbg(dev, "%s - Setting RTS\n", __func__); else dev_dbg(dev, "%s - Clearing RTS\n", __func__); @@ -462,7 +462,7 @@ static int kobil_tiocmset(struct tty_struct *tty, usb_sndctrlpipe(port->serial->dev, 0), SUSBCRequest_SetStatusLinesOrQueues, USB_TYPE_VENDOR | USB_RECIP_ENDPOINT | USB_DIR_OUT, - ((rts != 0) ? SUSBCR_SSL_SETRTS : SUSBCR_SSL_CLRRTS), + ((set & TIOCM_RTS) ? SUSBCR_SSL_SETRTS : SUSBCR_SSL_CLRRTS), 0, NULL, 0, -- 2.47.3