[PATCH 3.16 166/370] USB: serial: mos7720: fix parallel probe

Ben Hutchings
2017-03-10T12:24:29Z

From: Johan Hovold <johan@kernel.org>

commit fde1faf872ed86d88e245191bc15a8e57368cd1c upstream.

A static usb-serial-driver structure that is used to initialise the
interrupt URB was modified during probe depending on the currently
probed device type, something which could break a parallel probe of a
device of a different type.

Fix this up by overriding the default completion callback for MCS7715
devices in attach() instead. We may want to use two usb-serial driver
instances for the two types later.

Fixes: fb088e335d78 ("USB: serial: add support for serial port on the
moschip 7715")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/serial/mos7720.c | 30 +++++++-----------------------
1 file changed, 7 insertions(+), 23 deletions(-)

--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -65,8 +65,6 @@ struct moschip_port {
struct urb *write_urb_pool[NUM_URBS];
};

-static struct usb_serial_driver moschip7720_2port_driver;
-
#define USB_VENDOR_ID_MOSCHIP 0x9710
#define MOSCHIP_DEVICE_ID_7720 0x7720
#define MOSCHIP_DEVICE_ID_7715 0x7715
@@ -962,25 +960,6 @@ static void mos7720_bulk_out_data_callba
tty_port_tty_wakeup(&mos7720_port->port->port);
}

-/*
- * mos77xx_probe
- * this function installs the appropriate read interrupt endpoint callback
- * depending on whether the device is a 7720 or 7715, thus avoiding costly
- * run-time checks in the high-frequency callback routine itself.
- */
-static int mos77xx_probe(struct usb_serial *serial,
- const struct usb_device_id *id)
-{
- if (id->idProduct == MOSCHIP_DEVICE_ID_7715)
- moschip7720_2port_driver.read_int_callback =
- mos7715_interrupt_callback;
- else
- moschip7720_2port_driver.read_int_callback =
- mos7720_interrupt_callback;
-
- return 0;
-}
-
static int mos77xx_calc_num_ports(struct usb_serial *serial)
{
u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
@@ -1930,6 +1909,12 @@ static int mos7720_startup(struct usb_se
tmp->interrupt_in_endpointAddress;
serial->port[1]->interrupt_in_urb = NULL;
serial->port[1]->interrupt_in_buffer = NULL;
+
+ if (serial->port[0]->interrupt_in_urb) {
+ struct urb *urb = serial->port[0]->interrupt_in_urb;
+
+ urb->complete = mos7715_interrupt_callback;
+ }
}

/* setting configuration feature to one */
@@ -2043,7 +2028,6 @@ static struct usb_serial_driver moschip7
.close = mos7720_close,
.throttle = mos7720_throttle,
.unthrottle = mos7720_unthrottle,
- .probe = mos77xx_probe,
.attach = mos7720_startup,
.release = mos7720_release,
.port_probe = mos7720_port_probe,
@@ -2057,7 +2041,7 @@ static struct usb_serial_driver moschip7
.chars_in_buffer = mos7720_chars_in_buffer,
.break_ctl = mos7720_break,
.read_bulk_callback = mos7720_bulk_in_callback,
- .read_int_callback = NULL /* dynamically assigned in probe() */
+ .read_int_callback = mos7720_interrupt_callback,
};

static struct usb_serial_driver * const serial_drivers[] = {