RE: [PATCH] usbcore: fix BABBLE failed enumeration of legacy USB2devices on USB3 bus

[Marius Silaghi]

Great observation,
Sarah located a patch that is queued for the 3.14 kernel and that has a similar effect. So future kernels could work with that one as well.

The patch I provided (being very small and safe) can still be suggested for maintainers of older kernels in various long-term maintained distributions (if you know who is doing that).

Here are some versions of the patch I made for current kernels:

The next one was tested on Ubuntu, applied to the source for 3.5.0-17-generic (Ubuntu)

--- linux-3.5.0/drivers/usb/core/hub.c.orig	2014-01-07 18:16:01.997031650 -0500
+++ linux-3.5.0/drivers/usb/core/hub.c	2014-01-07 18:19:41.617022465 -0500
@@ -4043,7 +4043,11 @@
 				break;
   		}
 
-		retval = usb_get_device_descriptor(udev, 8);
+		if (!USE_NEW_SCHEME(retry_counter))
+		  retval = usb_get_device_descriptor(udev, 8);
+		else
+		  retval = usb_get_device_descriptor(udev,
+			    sizeof(struct usb_device_descriptor));
 		if (retval < 8) {
 			dev_err(&udev->dev,
 					"device descriptor read/8, error %d\n",


________________________________________
For kernel 3.9.0-0.4

--- linux-3.5.0/drivers/usb/core/hub.c.orig	2014-01-07 18:16:01.997031650 -0500
+++ linux-3.5.0/drivers/usb/core/hub.c	2014-01-07 18:19:41.617022465 -0500
@@ -4043,7 +4043,11 @@
 				break;
   		}
 
-		retval = usb_get_device_descriptor(udev, 8);
+		if (!USE_NEW_SCHEME(retry_counter))
+		  retval = usb_get_device_descriptor(udev, 8);
+		else
+		  retval = usb_get_device_descriptor(udev,
+			    sizeof(struct usb_device_descriptor));
 		if (retval < 8) {
 			dev_err(&udev->dev,
 					"device descriptor read/8, error %d\n",

________________________________________

For kernel 3.10.0-5.15

--- ubuntu-saucy/drivers/usb/core/hub.c.orig	2014-01-07 16:52:41.300835262 -0500
+++ ubuntu-saucy/drivers/usb/core/hub.c	2014-01-07 16:54:53.612829730 -0500
@@ -4126,8 +4126,11 @@
 			if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3))
 				break;
   		}
-
-		retval = usb_get_device_descriptor(udev, 8);
+		if (!USE_NEW_SCHEME(retry_counter))
+		  retval = usb_get_device_descriptor(udev, 8);
+		else
+		  retval = usb_get_device_descriptor(udev,
+			    sizeof(struct usb_device_descriptor));
 		if (retval < 8) {
 			if (retval != -ENODEV)
 				dev_err(&udev->dev,
________________________________________

For kernel 3.11
--- linux-3.11/drivers/usb/core/hub.c.orig	2014-01-07 16:57:16.352823760 -0500
+++ linux-3.11/drivers/usb/core/hub.c	2014-01-07 16:58:10.168821508 -0500
@@ -4161,7 +4161,11 @@
 				break;
   		}
 
-		retval = usb_get_device_descriptor(udev, 8);
+		if (!USE_NEW_SCHEME(retry_counter))
+		  retval = usb_get_device_descriptor(udev, 8);
+		else
+		  retval = usb_get_device_descriptor(udev,
+			    sizeof(struct usb_device_descriptor));
 		if (retval < 8) {
 			if (retval != -ENODEV)
 				dev_err(&udev->dev,


________________________________________
From: linux-usb-owner@xxxxxxxxxxxxxxx [linux-usb-owner@xxxxxxxxxxxxxxx] on behalf of Greg Kroah-Hartman [gregkh@xxxxxxxxxxxxxxxxxxx]
Sent: Tuesday, January 07, 2014 19:32
To: Marius  Silaghi
Cc: Sarah Sharp; linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Alan Stern; Lan Tianyu; Xenia Ragiadakou; Jiri Kosina
Subject: Re: [PATCH] usbcore: fix BABBLE failed enumeration of legacy USB2 devices on USB3 bus

On Tue, Dec 24, 2013 at 04:19:18AM +0000, Marius  Silaghi wrote:
> From: Marius C Silaghi <msilaghi@xxxxxxx>
>
> This patch is generated against the last kernel version in the github kernel repository.

We work off of the git.kernel.org trees, not github :)


> Some older families of USB2 cameras (STC-XXXXXUSB) do not support querying only the first 8 bytes of their
> device descriptor and therefore fail at enumeration on USB3 HCDs, with babble error -75 as they send more than
> the expected 8 bytes. The proposed patch extends the mechanism used for non USB3 HCDs in the first part of
> the same function, and  successively tries to query both the 8 byte prefix of the device descriptor, as well as
> the whole device descriptor (in case the old style query of the 8 byte prefix fails).
> In fact, for the cameras I try to fix, the preferred condition is the negation of the one in the proposed patch,
> "if (!USE_NEW_SCHEME(retry_counter))", to try first the version successful on this case, but I keep the
> current order of the "if" branches to ensure clean continuation of support for other supported devices.
>
> Signed-off-by: Marius C Silaghi <msilaghi@xxxxxxx>

I'll let Sarah take this patch, if it passes her testing.

thanks,

greg k-h
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