From: Johan Hovold <johan@xxxxxxxxxx> commit bc4b1f486fe69b86769e07c8edce472327a8462b upstream. This reverts commit 5083fd7bdfe6760577235a724cf6dccae13652c2. A bulk-out size smaller than the end-point size is indeed valid. The offending commit broke the usb-debug driver for EHCI debug devices, which use 8-byte buffers. Fixes: 5083fd7bdfe6 ("USB: serial: make bulk_out_size a lower limit") Reported-by: "Li, Elvin" <elvin.li@xxxxxxxxx> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx> --- drivers/usb/serial/usb-serial.c | 5 +++-- include/linux/usb/serial.h | 3 +-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 475723c..1984237 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -940,8 +940,9 @@ static int usb_serial_probe(struct usb_interface *interface, port = serial->port[i]; if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL)) goto probe_error; - buffer_size = max_t(int, serial->type->bulk_out_size, - usb_endpoint_maxp(endpoint)); + buffer_size = serial->type->bulk_out_size; + if (!buffer_size) + buffer_size = usb_endpoint_maxp(endpoint); port->bulk_out_size = buffer_size; port->bulk_out_endpointAddress = endpoint->bEndpointAddress; diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index 9bb547c..704a1ab 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -190,8 +190,7 @@ static inline void usb_set_serial_data(struct usb_serial *serial, void *data) * @num_ports: the number of different ports this device will have. * @bulk_in_size: minimum number of bytes to allocate for bulk-in buffer * (0 = end-point size) - * @bulk_out_size: minimum number of bytes to allocate for bulk-out buffer - * (0 = end-point size) + * @bulk_out_size: bytes to allocate for bulk-out buffer (0 = end-point size) * @calc_num_ports: pointer to a function to determine how many ports this * device has dynamically. It will be called after the probe() * callback is called, but before attach() -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html