usb.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
Signature · 4 lines
Dmitri Kassatkine Nokia Research Center / Helsinki Mobile: +358 50 4836365 E-Mail: [email protected]
usb.c renamed from usb.c.orig +20 -15
@@ -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;