Merge tag 'usb-serial-5.11-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-next

Johan writes:

USB-serial updates for 5.11-rc1

Here are the USB-serial updates for 5.11-rc1, including:

 - keyspan_pda write-implementation fixes
 - digi_acceleport write-wakeup fix
 - mos7720 parport-restore fix
 - mos7720 parport-tasklet removal
 - cp210x termios-handling cleanups
 - option device-flag fix
 - ftdi_sio GPIO CBUS-configuration improvements
 - removal of in_interrupt() uses

Included are also various clean ups.

All have been in linux-next with no reported issues.

* tag 'usb-serial-5.11-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial: (30 commits)
  USB: serial: ftdi_sio: log the CBUS GPIO validity
  USB: serial: ftdi_sio: drop GPIO line checking dead code
  USB: serial: ftdi_sio: report the valid GPIO lines to gpiolib
  USB: serial: option: add interface-number sanity check to flag handling
  USB: serial: cp210x: clean up dtr_rts()
  USB: serial: cp210x: refactor flow-control handling
  USB: serial: cp210x: drop flow-control debugging
  USB: serial: cp210x: set terminal settings on open
  USB: serial: cp210x: clean up line-control handling
  USB: serial: cp210x: return early on unchanged termios
  USB: serial: mos7720: defer state restore to a workqueue
  USB: serial: mos7720: fix parallel-port state restore
  USB: serial: remove write wait queue
  USB: serial: digi_acceleport: fix write-wakeup deadlocks
  USB: serial: keyspan_pda: drop redundant usb-serial pointer
  USB: serial: keyspan_pda: use BIT() macro
  USB: serial: keyspan_pda: clean up comments and whitespace
  USB: serial: keyspan_pda: clean up xircom/entrega support
  USB: serial: keyspan_pda: add write-fifo support
  USB: serial: keyspan_pda: increase transmitter threshold
  ...

1 files changed, 21 insertions, 2 deletions

diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index 56d6f6d83bd7..2c21e34235bb 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -563,6 +563,9 @@ static void option_instat_callback(struct urb *urb);
 
 /* Device flags */
 
+/* Highest interface number which can be used with NCTRL() and RSVD() */
+#define FLAG_IFNUM_MAX	7
+
 /* Interface does not support modem-control requests */
 #define NCTRL(ifnum)	((BIT(ifnum) & 0xff) << 8)
 
@@ -2101,6 +2104,14 @@ static struct usb_serial_driver * const serial_drivers[] = {
 
 module_usb_serial_driver(serial_drivers, option_ids);
 
+static bool iface_is_reserved(unsigned long device_flags, u8 ifnum)
+{
+	if (ifnum > FLAG_IFNUM_MAX)
+		return false;
+
+	return device_flags & RSVD(ifnum);
+}
+
 static int option_probe(struct usb_serial *serial,
 			const struct usb_device_id *id)
 {
@@ -2117,7 +2128,7 @@ static int option_probe(struct usb_serial *serial,
 	 * the same class/subclass/protocol as the serial interfaces.  Look at
 	 * the Windows driver .INF files for reserved interface numbers.
 	 */
-	if (device_flags & RSVD(iface_desc->bInterfaceNumber))
+	if (iface_is_reserved(device_flags, iface_desc->bInterfaceNumber))
 		return -ENODEV;
 
 	/*
@@ -2133,6 +2144,14 @@ static int option_probe(struct usb_serial *serial,
 	return 0;
 }
 
+static bool iface_no_modem_control(unsigned long device_flags, u8 ifnum)
+{
+	if (ifnum > FLAG_IFNUM_MAX)
+		return false;
+
+	return device_flags & NCTRL(ifnum);
+}
+
 static int option_attach(struct usb_serial *serial)
 {
 	struct usb_interface_descriptor *iface_desc;
@@ -2148,7 +2167,7 @@ static int option_attach(struct usb_serial *serial)
 
 	iface_desc = &serial->interface->cur_altsetting->desc;
 
-	if (!(device_flags & NCTRL(iface_desc->bInterfaceNumber)))
+	if (!iface_no_modem_control(device_flags, iface_desc->bInterfaceNumber))
 		data->use_send_setup = 1;
 
 	if (device_flags & ZLP)