[v2] usb: do not reset if a low-speed or full-speed device timed out

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Jan 04, 2018 at 09:43:03PM +0300, Maxim Moseychuk wrote:
> Some low-speed and full-speed devices (for example, bluetooth)
> do not have time to initialize. For them, ETIMEDOUT is a valid error.
> We need to give them another try. Otherwise, they will
> never be initialized correctly and in dmesg will be messages
> "Bluetooth: hci0 command 0x1002 tx timeout" or similars.
> 
> Fixes: 264904ccc33c ("usb: retry reset if a device times out")
> Cc: stable <stable@vger.kernel.org>
> Signed-off-by: Maxim Moseychuk <franchesko.salias.hudro.pedros@gmail.com>
> ---
>  drivers/usb/core/hub.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index cf7bbcb9a63c..775d97035503 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -4524,7 +4524,9 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
>  				 * reset. But only on the first attempt,
>  				 * lest we get into a time out/reset loop
>  				 */
> -				if (r == 0  || (r == -ETIMEDOUT && retries == 0))
> +				if (r == 0 || (r == -ETIMEDOUT &&
> +						retries == 0 &&
> +						udev->speed > USB_SPEED_FULL))
>  					break;

But can't we now get into a loop where this never happens?  We still
need to "fail" these slow devices somehow.

Do you have a device that this fixes a problem for?  I would think we
would have seen this issue before now, given that this change has been
present in the tree for quite some time now.

thanks,

greg k-h
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