On Sun, Feb 15, 2015 at 12:43:51AM +0000, Li, Elvin wrote: > Hi All, > I am using usb_debug driver in Linux kernel to manage > Ajays USB debug device (Vendor Id: 0525 Product Id: > 127a) which follows EHCI debug device specification. > drivers\usb\serial\usb_debug.c was developed by Greg > Kroah-Hartman, it worked very well with Ajays debug > device until one change to usb-serial.c. I could see > the Johan's change at > https://github.com/torvalds/linux/commit/5083fd7bdfe6760577235a724cf6dccae13652c2. > Does anyone has ideas how the issue could be resolved? Thanks for the report. The commit mentioned above should simply be reverted; a bulk-out buffer size smaller than the end-point size is indeed valid. Could you verify that the patch below fixes the issues you're seeing? Thanks, Johan >From fffe54908863974c20adf1b1bf4e24e35a8d921b Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan@xxxxxxxxxx> Date: Sun, 15 Feb 2015 11:57:53 +0700 Subject: [PATCH] Revert "USB: serial: make bulk_out_size a lower limit" 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> Cc: stable <stable@xxxxxxxxxxxxxxx> # v3.15 Signed-off-by: Johan Hovold <johan@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 475723c006f9..19842370a07f 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 9bb547c7bce7..704a1ab8240c 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() -- 2.0.5 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
