Hi Johan,
Your patch fixed my issue. Thank you for support!
Regards
Elvin Li
-----Original Message-----
From: Johan Hovold [mailto:[email protected]] On Behalf Of Johan Hovold
Sent: Sunday, February 15, 2015 1:16 PM
To: Li, Elvin
Cc: [email protected]; [email protected]; Tian, Feng; Ni,
Ruiyu; [email protected]; [email protected]
Subject: Re: Usb serial driver change question in the linux kernel
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 <[email protected]>
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" <[email protected]>
Cc: stable <[email protected]> # v3.15
Signed-off-by: Johan Hovold <[email protected]>
---
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
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