Re: [PACTH v2] cdc-wdm: Clear read pipeline in case of error

From	Robert Foss <robert.foss@collabora.com>
Newsgroups	linux.kernel
Subject	Re: [PACTH v2] cdc-wdm: Clear read pipeline in case of error
Date	2016-08-09 16:30 +0200
Message-ID	<s4gcy-je-29@gated-at.bofh.it> (permalink)
References	<s3UYp-3dx-1@gated-at.bofh.it> <s4fJw-8kJ-33@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 2016-08-09 09:51 AM, Greg KH wrote:
> On Mon, Aug 08, 2016 at 11:48:52AM -0400, robert.foss@collabora.com wrote:
>> From: Robert Foss <robert.foss@collabora.com>
>>
>> Implemented queued response handling. This queue is processed every time the
>> WDM_READ flag is cleared.
>>
>> In case of a read error, userspace may not actually read the data, since the
>> driver returns an error through wdm_poll. After this, the underlying device may
>> attempt to send us more data, but the queue is not processed. While userspace is
>> also blocked, because the read error is never cleared.
>>
>> After this patch, we proactively process the queue on a read error. If there was
>> an outstanding response to handle, that will clear the error (or go through the
>> same logic again, if another read error occurs). If there was no outstanding
>> response, this will bring the queue size back to 0, unblocking a future response
>> from the underlying device.
>>
>> Tested-by: Robert Foss <robert.foss@collabora.com>
>> Signed-off-by: Robert Foss <robert.foss@collabora.com>
>> Acked-by: Oliver Neukum <oneukum@suse.com>

Thanks Oliver!

>> ---
>>
>> Changes since v1:
>> - Only set a new error code it there is no previous error code
>
> This no longer applies to my tree due to a patch sent before yours for
> the same driver.  Can you resync against my usb-testing brance on my
> usb.git tree on git.kernel.org and resend?
>

Will do!

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[PACTH v2] cdc-wdm: Clear read pipeline in case of error robert.foss@collabora.com - 2016-08-08 17:50 +0200
  Re: [PACTH v2] cdc-wdm: Clear read pipeline in case of error Oliver Neukum <oneukum@suse.com> - 2016-08-09 14:30 +0200
  Re: [PACTH v2] cdc-wdm: Clear read pipeline in case of error Greg KH <gregkh@linuxfoundation.org> - 2016-08-09 16:00 +0200
    Re: [PACTH v2] cdc-wdm: Clear read pipeline in case of error Robert Foss <robert.foss@collabora.com> - 2016-08-09 16:30 +0200

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