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From: Ivo Sieben <meltedpianoman@gmail.com>
To: Alan Cox <alan@linux.intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
	linux-serial@vger.kernel.org, RT <linux-rt-users@vger.kernel.org>
Subject: Re: [PATCH] tty: prevent unnecessary work queue lock checking on flip buffer copy
Date: Mon, 24 Sep 2012 11:33:17 +0200	[thread overview]
Message-ID: <CAMSQXEGEf8xSYZa+0N77K-Ld5xHLefyMHtK6FxcKCqNhpnMp6g@mail.gmail.com> (raw)
In-Reply-To: <20120920173305.15ea580a@bob.linux.org.uk>

Hi,

2012/9/20 Alan Cox <alan@linux.intel.com>:
>
> This seems reasonable, but given its also relevant for upstream it
> would be nice to get it without the ifdef in upstream.
>
> The corner case is when the tty->low_latency flag is flipped but the
> drivers should handle that gracefully and if not we should fix them so
> you can get your 100uS.
>
> Alan

Actually this patch is related to my previous patch "tty: cleanup
duplicate functions in tty_buffer". Some drivers call the
tty_schedule_flip() function instead of tty_flip_buffer_push(). In
that case the work queue is always used, regardless the
tty->low_latency flag. That's why tried to get rid of the
tty_schedule_flip() function.

But from the first review remarks on the "tty: cleanup duplicate
functions in tty_buffer" patch, that patch seems to be invalid. So in
that case this patch is invalid also.

Regards,
Ivo Sieben

  reply	other threads:[~2012-09-24  9:33 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-20 14:02 [PATCH] tty: prevent unnecessary work queue lock checking on flip buffer copy Ivo Sieben
2012-09-20 16:33 ` Alan Cox
2012-09-24  9:33   ` Ivo Sieben [this message]
2012-09-25 12:01     ` [PATCH-v2] " Ivo Sieben
2012-09-25 13:06       ` Alan Cox
2012-09-25 14:39         ` Ivo Sieben
2012-09-25 14:47           ` Alan Cox
2012-09-27 11:58             ` [PATCH-v3] " Ivo Sieben
2012-09-27 12:02               ` Ivo Sieben
2012-10-22 23:47                 ` Greg KH
2012-10-23 10:16                   ` Alan Cox
2012-10-24 12:35                     ` [PATCH] [tty]: Report warning when low_latency flag is wrongly used Ivo Sieben
2012-10-24 14:32                       ` Paul Gortmaker
2012-10-24 18:22                     ` [PATCH-v3] tty: prevent unnecessary work queue lock checking on flip buffer copy Greg KH
2012-09-27 13:15               ` Alan Cox
2012-09-27 16:53                 ` Greg KH

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