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From: Felipe Balbi <balbi@kernel.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: USB mailing list <linux-usb@vger.kernel.org>
Subject: Re: Disconnect race in Gadget core
Date: Mon, 17 May 2021 08:35:50 +0300	[thread overview]
Message-ID: <87tun16hxl.fsf@kernel.org> (raw)
In-Reply-To: <20210516145151.GC1060053@rowland.harvard.edu>

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Hi,

Alan Stern <stern@rowland.harvard.edu> writes:
> On Sun, May 16, 2021 at 12:43:58PM +0300, Felipe Balbi wrote:
>> 
>> Hi,
>> 
>> Alan Stern <stern@rowland.harvard.edu> writes:
>> >
>> > If it's okay to call those functions in interrupt context then the 
>> > kerneldoc definitely should be updated.  However, I don't see why you 
>> > would want to make DELAYED_STATUS mandatory.  If all the necessary work 
>> > can be done in the set_alt handler, why not return the status 
>> > immediately?
>> 
>> because we avoid a special case. Instead of having magic return value to
>> mean "Don't do anything until I enqueue a request" we can just make that
>> an assumption, i.e. gadget driver *must* enqueue requests for data and
>> status stages.
>
> Okay.  But that would require auditing every gadget/function driver to 
> ensure that they _do_ enqueue status stage requests, and auditing every 
> UDC driver to ensure they don't send unsolicited status responses to 
> control requests with data stages.  Until this happens, we're forced to 
> use the DELAYED_STATUS magic value.

sure, that's work for the future :-)

-- 
balbi

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      parent reply	other threads:[~2021-05-17  5:36 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-10 15:24 Disconnect race in Gadget core Alan Stern
2021-05-10 16:43 ` Felipe Balbi
2021-05-10 19:38   ` Alan Stern
2021-05-11  2:53     ` Peter Chen
2021-05-11 19:15       ` Alan Stern
2021-05-12  9:37         ` Peter Chen
2021-05-12  9:41           ` Felipe Balbi
2021-05-12 19:33           ` Alan Stern
2021-05-11  8:22     ` Felipe Balbi
2021-05-11 21:26       ` Alan Stern
2021-05-12  7:00         ` Felipe Balbi
2021-05-12 15:33           ` Alan Stern
2021-05-14  7:35             ` Felipe Balbi
2021-05-14 16:58               ` Alan Stern
2021-05-15  6:41                 ` Felipe Balbi
2021-05-15 15:31                   ` Alan Stern
2021-05-16  9:43                     ` Felipe Balbi
2021-05-16 14:51                       ` Alan Stern
2021-05-17  2:00                         ` Peter Chen
2021-05-17  5:33                           ` Felipe Balbi
2021-05-17  5:35                         ` Felipe Balbi [this message]

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