From: Felipe Balbi <balbi@kernel.org>
To: Alan Stern <stern@rowland.harvard.edu>,
Baolin Wang <baolin.wang@linaro.org>
Cc: Greg KH <gregkh@linuxfoundation.org>,
USB <linux-usb@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linaro Kernel Mailman List <linaro-kernel@lists.linaro.org>,
Mark Brown <broonie@kernel.org>
Subject: Re: [PATCH] usb: dwc3: ep0: Fix the possible missed request for handling delay STATUS phase
Date: Tue, 28 Feb 2017 13:56:39 +0200 [thread overview]
Message-ID: <87tw7ettoo.fsf@linux.intel.com> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1702271706400.6449-100000@netrider.rowland.org>
Hi,
Alan Stern <stern@rowland.harvard.edu> writes:
>> So I am not sure how the Gadget driver can figure out that it needs to
>> usb_ep_queue() another request for status stage when handling the
>> no-data control?
>
> Gadget drivers already queue status-stage requests for no-data
> control-OUT requests. The difficulty comes when you want to handle an
> IN request or an OUT request with a data stage.
I don't see a difficulty there. Gadget driver will see wLength and
notice it needs both data and status stages, then it does:
usb_ep_queue(ep0, data_req, GFP_KERNEL);
usb_ep_queue(ep0, status_req, GFP_KERNEL);
Just needs to prepare both requests and queue them both ahead of
time. UDC drivers should hold both requests in their own private list
and process one at a time.
--
balbi
next prev parent reply other threads:[~2017-02-28 12:09 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-14 8:40 [PATCH] usb: dwc3: ep0: Fix the possible missed request for handling delay STATUS phase Baolin Wang
2017-01-16 10:56 ` Felipe Balbi
2017-01-16 11:29 ` Baolin Wang
2017-01-16 11:29 ` Felipe Balbi
2017-01-16 12:00 ` Baolin Wang
2017-01-16 12:06 ` Felipe Balbi
2017-01-16 17:53 ` Alan Stern
2017-01-16 19:18 ` Felipe Balbi
2017-01-17 15:54 ` Alan Stern
2017-01-23 11:57 ` Felipe Balbi
2017-02-17 5:41 ` Baolin Wang
2017-02-17 8:04 ` Felipe Balbi
2017-02-20 2:27 ` Baolin Wang
2017-02-21 9:18 ` Baolin Wang
2017-02-27 22:11 ` Alan Stern
2017-02-28 11:56 ` Felipe Balbi [this message]
2017-02-28 18:34 ` Alan Stern
2017-03-02 10:43 ` Felipe Balbi
2017-03-02 10:15 ` Baolin Wang
2017-03-02 10:48 ` Felipe Balbi
2017-01-17 7:02 ` Baolin Wang
2017-01-17 10:39 ` Felipe Balbi
2017-01-17 11:40 ` Baolin Wang
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