On 01/12/2015 11:14 AM, Ahmed S. Darwish wrote:
> On Sun, Jan 11, 2015 at 09:51:10PM +0100, Marc Kleine-Budde wrote:
>> On 01/11/2015 09:45 PM, Ahmed S. Darwish wrote:
>>> From: Ahmed S. Darwish <ahmed.darwish@xxxxxxxxx>
>>>
>>> (This is a draft patch, I'm not sure if this fixes the USB
>>> bug or only its psymptom. Feedback from the linux-usb folks
>>> is really appreciated.)
>>>
>>> When plugging the Kvaser USB/CAN dongle the first time, everything
>>> works as expected and all of the transfers from and to the USB
>>> device succeeds.
>>>
>>> Meanwhile, after unplugging the device and plugging it again, the
>>> first bulk transfer _always_ returns an -ETIMEDOUT. The following
>>> behaviour was observied:
>>>
>>> - Setting higher timeout values for the first bulk transfer never
>>> solved the issue.
>>>
>>> - Unloading, then loading, our kvaser_usb module in question
>>> __always__ solved the issue.
>>>
>>> - Checking first bulk transfer status, and retry the transfer
>>> again in case of an -ETIMEDOUT also __always__ solved the issue.
>>> This is what the patch below does.
>>>
>>> - In the testing done so far, this issue appears only on laptops
>>> but never on PCs (possibly power related?)
>>>
>>> Signed-off-by: Ahmed S. Darwish <ahmed.darwish@xxxxxxxxx>
>>
>> Does this patch apply apply between 3 and 4? If not, please re-arrange
>> the series. As this is a bug fix, patches 1, 2 and 4 will go via
>> net/master, 3 will go via net-next/master.
>
> Since no one complained earlier, I guess this issue only affects
> USBCAN devices. That's why I've based it above patch #3: adding
> USBCAN hardware support.
>
> Nonetheless, it won't do any harm for the current Leaf-only
> driver. So _if_ this is the correct fix, I will update the commit
> log, refactor the check into a 'do { } while()' loop, and then
> base it above the Leaf-only net/master fixes on patch #1, and #2.
>
> Any feedback on the USB side of things?
Maybe you have to change the subject of this patch to be more visible on
the USB list and/or add the right USB people on Cc.
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
Attachment:
signature.asc
Description: OpenPGP digital signature
