Groups > linux.kernel > #1190045

Re: [PATCH] Fix data loss in cdc-acm

From	Oliver Neukum <oneukum@suse.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] Fix data loss in cdc-acm
Date	2015-07-22 17:10 +0200
Message-ID	<pP3OG-1Xp-7@gated-at.bofh.it> (permalink)
References	(2 earlier) <pOnFM-nL-23@gated-at.bofh.it> <pOBSp-415-5@gated-at.bofh.it> <pOITU-5xi-1@gated-at.bofh.it> <pOXSV-1JX-3@gated-at.bofh.it> <pP3lD-19S-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, 2015-07-22 at 10:30 -0400, Peter Hurley wrote:
> 3. Pre-allocate space _before_ the data arrives (with
> tty_buffer_request_room());
>    this is applicable to subsystems which know how much data can be
> in-flight
>    at any one time. This guarantees that when rx data arrives buffer
> space is
>    available (since it has already been allocated).
> 
> Drivers that use method 2 typically attempt to recopy the buffered
> data
> when either new data arrives or @ unthrottle. I've seen others use
> deferred
> work as well.
> 
> AFAIK no driver/subsystem is using method 3 for guaranteed delivery
> of in-flight data, but it seems ideally suited to usb serial.

Indeed. But flow control is still done by throttle/unthrottle, isn't it?

	Regards
		Oliver


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Thread

[PATCH] Fix data loss in cdc-acm Sven Brauch <mail@svenbrauch.de> - 2015-07-19 23:50 +0200
  Re: [PATCH] Fix data loss in cdc-acm Johan Hovold <johan@kernel.org> - 2015-07-20 19:30 +0200
    Re: [PATCH] Fix data loss in cdc-acm Sven Brauch <mail@svenbrauch.de> - 2015-07-20 20:10 +0200
      Re: [PATCH] Fix data loss in cdc-acm Oliver Neukum <oneukum@suse.com> - 2015-07-22 10:50 +0200
        Re: [PATCH] Fix data loss in cdc-acm Peter Hurley <peter@hurleysoftware.com> - 2015-07-22 16:40 +0200
          Re: [PATCH] Fix data loss in cdc-acm Oliver Neukum <oneukum@suse.com> - 2015-07-22 17:10 +0200
      Re: [PATCH] Fix data loss in cdc-acm Sven Brauch <mail@svenbrauch.de> - 2015-07-23 01:00 +0200
        Re: [PATCH] Fix data loss in cdc-acm Peter Stuge <peter@stuge.se> - 2015-07-27 12:10 +0200

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