USB: debug port converter does not accept more than 8 byte packets (71be4f81) · Commits · e / devices / android_kernel_teracube_emerald

USB debug port only supports 8 byte rx/tx packets. Although spec implies that "if a packet larger than eight bytes is received from the remote computer, the device must break the larger packet into eight-byte packets before sending the data to the Debug Port", the real PLX NET20DC device does not handle it right - data is corrupted on debug port end if serial interface sends >8 byte urbs. Patch below fixes the issue by limiting tx urb to 8 byte. Signed off by: Aleks Gorelov <dared1st@yahoo.com> Signed-off-by:

Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/usb_debug.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,8 @@
		#include <linux/usb.h>
		#include <linux/usb/serial.h>

		#define USB_DEBUG_MAX_PACKET_SIZE 8

		static struct usb_device_id id_table [] = {
		{ USB_DEVICE(0x0525, 0x127a) },
		{ },
		@@ -29,6 +31,12 @@ static struct usb_driver debug_driver = {
		.no_dynamic_id = 1,
		};

		int usb_debug_open(struct usb_serial_port port, struct file filp)
		{
		port->bulk_out_size = USB_DEBUG_MAX_PACKET_SIZE;
		return usb_serial_generic_open(port, filp);
		}

		static struct usb_serial_driver debug_device = {
		.driver = {
		.owner = THIS_MODULE,
		@@ -36,6 +44,7 @@ static struct usb_serial_driver debug_device = {
		},
		.id_table = id_table,
		.num_ports = 1,
		.open = usb_debug_open,
		};

		static int __init debug_init(void)