Re: [PATCH] USB: output an error message when the pipe type doesn'tmatch the endpoint type

From: Simon Arlott
Date: Thu Sep 02 2010 - 13:11:32 EST


On 02/09/10 15:22, Alan Stern wrote:
> On Thu, 2 Sep 2010, Simon Arlott wrote:
>
>> On Wed, September 1, 2010 18:49, Alan Stern wrote:
>> > On Wed, 1 Sep 2010, Simon Arlott wrote:
>> >> > This is okay with me. If you're serious about not changing the
>> >> > behavior merely because debugging is enabled, you could move this test
>> >> > out of the debug-only region and possibly change the dev_err to
>> >> > dev_dbg. However doing so might break some devices that are currently
>> >> > working.
>
> Which suggests that the best approach is to print the error message
> always, but allow the submission unless CONFIG_USB_DEBUG is set.

That could result in a lot of error messages, and it doesn't give any
information on which driver caused it, but a single WARN_ON() would
only be triggered once globally. Each USB device (or endpoint) could
have a "warned" flag.

>> Looking at usb_clear_halt(), it doesn't use the direction either... but
>> drivers can call it in both directions. Several drivers already do this.
>
> What do you mean? Look at the first lines of code in usb_clear_halt():
>
> if (usb_pipein(pipe))
> endp |= USB_DIR_IN;

Sorry, I misread it as always selecting the same direction.

--
Simon Arlott
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