From: Oliver Neukum <oneukum@suse.de>
Organization: SUSE
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH] USB: cdc-acm: Prevent data loss when filling tty buffer.
Date: Tue, 22 Mar 2011 09:07:42 +0100
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Cc: Toby Gray <toby.gray@realvnc.com>, "Greg Kroah-Hartman" <gregkh@suse.de>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
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Am Montag, 21. M?rz 2011, 17:56:12 schrieb Alan Cox:
> On Mon, 21 Mar 2011 15:52:25 +0000
> Toby Gray <toby.gray@realvnc.com> wrote:
> 
> > When sending large quantities of data through a CDC ACM channel it is possible
> > for data to be lost when attempting to copy the data to the tty buffer. This
> > occurs due to the return value from tty_insert_flip_string not being checked.
> 
> For a tty that is normally the right thing to do - no flow control was
> asserted and the internal 64K of buffering was overrun so discard.

But should we really randomly discard a part of a buffer?
If this happens the better alternative approach would be to nuke all buffers
we currently have.

	Regards
		Oliver
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