From: Alan Cox <alan@redhat.com>
To: Sergei Organov <osv@javad.com>
Cc: Alan Cox <alan@redhat.com>, linux-serial@vger.kernel.org
Subject: Re: [Q] New tty flip interface doubt.
Date: Thu, 22 Jun 2006 08:56:52 -0400 [thread overview]
Message-ID: <20060622125652.GA23090@devserv.devel.redhat.com> (raw)
In-Reply-To: <87irmt63wk.fsf@javad.com>
On Thu, Jun 22, 2006 at 11:33:15AM +0400, Sergei Organov wrote:
> One more question, if I get memory for N bytes with
> tty_prepare_flip_string() then store M (M <= N) bytes into the buffer,
> how do I tell tty layer that only M bytes are in fact stored?
You don't.
> [I'm thinking about eliminating buffers allocation for urbs as well as
> data copy when transferring data from USB subsystem to flip buffers of
> the tty subsystem. Currently the flow is:
The tty buffers may not be DMAable
> and it seems that using tty buffers directly is a better idea:
>
> - allocate N-bytes data buffer from tty and use it for urb
> - submit the urb to USB subsystem
> - flip M-bytes of data (M <= N) in USB receive callback.
Its doable in theory but is it worth it ?
next prev parent reply other threads:[~2006-06-22 12:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-06-21 12:16 [Q] New tty flip interface doubt Sergei Organov
2006-06-21 13:42 ` Alan Cox
2006-06-22 7:33 ` Sergei Organov
2006-06-22 12:56 ` Alan Cox [this message]
2006-06-22 15:17 ` Sergei Organov
2006-06-23 13:16 ` Alan Cox
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