lkml.org 
[lkml]   [2002]   [Jan]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subjectusb.c patch -> successfuly read usb descriptors on some USB device
Hi,

Sometimes USB subsystem cannot get USB descriptor.

Jan 15 10:44:21 selma kernel: hub.c: USB new device connect on bus1/1,
assign
ed device number 25
Jan 15 10:44:21 selma kernel: usb.c: couldn't get all of config descriptors
Jan 15 10:44:21 selma kernel: usb.c: unable to get device 25
configuration (e
rror=-110)


Here is patch how to fix it for 2.4.17. It works for 2.4.16 as well.
It necassary to read descriptor at once, not first 8 byte first.

It works well now for NSM USB Bluetooth dongle.

br, Dmitri


----------------------------- CUT HERE ---------------------------------------------------------
--- usb.c.orig Wed Nov 21 19:59:11 2001
+++ usb.c Tue Jan 15 11:38:35 2002
@@ -2041,7 +2041,7 @@
return -ENOMEM;
}

- buffer = kmalloc(8, GFP_KERNEL);
+ buffer = kmalloc(255, GFP_KERNEL);
if (!buffer) {
err("unable to allocate memory for configuration descriptors");
return -ENOMEM;
@@ -2049,9 +2049,9 @@
desc = (struct usb_config_descriptor *)buffer;

for (cfgno = 0; cfgno < dev->descriptor.bNumConfigurations; cfgno++) {
- /* We grab the first 8 bytes so we know how long the whole */
+ /* We grab the first 255 bytes so we know how long the whole */
/* configuration is */
- result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, buffer, 8);
+ result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, buffer, 255);
if (result < 8) {
if (result < 0)
err("unable to get descriptor");
@@ -2072,19 +2072,24 @@
goto err;
}

- /* Now that we know the length, get the whole thing */
- result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, bigbuffer, length);
- if (result < 0) {
- err("couldn't get all of config descriptors");
- kfree(bigbuffer);
- goto err;
- }
+ if (length > 255) {
+ /* Now that we know the length, get the whole thing */
+ result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, bigbuffer, length);
+ if (result < 0) {
+ err("couldn't get all of config descriptors");
+ kfree(bigbuffer);
+ goto err;
+ }

- if (result < length) {
- err("config descriptor too short (expected %i, got %i)", length, result);
- result = -EINVAL;
- kfree(bigbuffer);
- goto err;
+ if (result < length) {
+ err("config descriptor too short (expected %i, got %i)", length, result);
+ result = -EINVAL;
+ kfree(bigbuffer);
+ goto err;
+ }
+ }
+ else {
+ memcpy(bigbuffer, buffer, length);
}

dev->rawdescriptors[cfgno] = bigbuffer;
-------------- CUT HERE ----------------------------------------------------------------------------
--
Dmitri Kassatkine
Nokia Research Center / Helsinki
Mobile: +358 50 4836365
E-Mail: dmitri.kassatkine@nokia.com



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:22    [W:0.038 / U:2.760 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site