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From: Stefan Bigler <stefan.bigler@keymile.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <greg@kroah.com>,
	linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: TTY loosing data with u_serial gadget
Date: Fri, 18 Mar 2011 22:15:40 +0100	[thread overview]
Message-ID: <4D83CB7C.8040903@keymile.com> (raw)
In-Reply-To: <20110318180718.6d019c71@lxorguk.ukuu.org.uk>


> In essence if you get a value from receive_room it's a guarantee you may
> send that many bytes, it is not a precise instantaneous perfect answer to
> the question "exactly what number of bytes could fit at this precise
> moment".
>
Hi

I have no problem with having more space available than guarantied by
the value of receive_room. But what I see is that the value can be less!
Data will be lost.
My test showed:
  data to queue=201
  receive_room (guarantied space) =287
  real space in queue =0
In the last mail I attached the code for printing, the read_lock was only
added to show a constistant view of all current values.

Stefan

      reply	other threads:[~2011-03-18 21:20 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-16 20:47 TTY loosing data with u_serial gadget Stefan Bigler
2011-03-17  0:04 ` Greg KH
2011-03-18 16:35   ` Stefan Bigler
2011-03-18 17:08     ` Felipe Balbi
2011-03-18 18:06       ` Alan Cox
2011-03-21  9:32         ` Felipe Balbi
2011-03-22  8:53           ` Felipe Balbi
2011-03-22 11:04             ` Alan Cox
2011-03-22 17:01               ` Greg KH
2011-03-24 12:07             ` Toby Gray
2011-03-24 12:37               ` Felipe Balbi
2011-03-24 12:51                 ` Toby Gray
2011-03-24 13:00                   ` Felipe Balbi
2011-03-24 15:40                     ` Stefan Bigler
2011-03-24 16:15                       ` Toby Gray
2011-03-25 11:02                         ` Felipe Balbi
2011-03-18 21:46       ` Stefan Bigler
2011-03-18 18:07     ` Alan Cox
2011-03-18 21:15       ` Stefan Bigler [this message]

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