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: [email protected] [[email protected]] on
behalf of Greg Kroah-Hartman [[email protected]]
Sent: Tuesday, January 07, 2014 19:32
To: Marius Silaghi
Cc: Sarah Sharp; [email protected]; [email protected]; 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 <[email protected]>
>
> 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 <[email protected]>
I'll let Sarah take this patch, if it passes her testing.
thanks,
greg k-h
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