On Thu, Sep 23, 2010 at 09:35:06AM -0500, Alan Stern wrote:
On Thu, 23 Sep 2010, Felipe Balbi wrote:
On Thu, Sep 23, 2010 at 03:36:40AM -0500, Ming Lei wrote:
>2010/9/23 Felipe Balbi <balbi@xxxxxx>:
>> Hi,
>>
>> On Wed, Sep 22, 2010 at 10:15:09AM -0500, tom.leiming@xxxxxxxxx wrote:
>>>
>>> + if ((request->zero && request->length
>>
>> I think you can actually remove the request->length check, I doubt any
>> gadget driver will queue a request without length sent to something more
>> than 0. could you test that please ?
Gadget drivers queue requests with length set to 0 all the time. How
else could they send a ZLP?
Maybe they don't also set the request->zero flag, but I wouldn't depend
on it. Checking is safer.
>I think so too. But I am not sure, since I don't know why the
>request->length check is introduced, so I don't remove the check in
>the patch and just fix the ZLP issue only.
The check is there in order to prevent the controller driver from
sending _two_ ZLPs when the gadget driver queues a request with
request.length == 0 and request.zero set.
>Also seems req->zero is used in some corner case only, I don't think
>there are good test cases to verify the change of removing the check,
>right?
>
>So suggest to keep the check until we are sure it is safe to remove it.
makes sense :-) I'll try to play around with removing request->length
check after merge window then :-)
Even if it never gets used, better safe than sorry. It's not like this
test takes up multiple megabytes of code space.
ok, keeping.
--
balbi
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