From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Johan Hovold <johan@kernel.org>
Cc: Jiri Slaby <jirislaby@kernel.org>,
linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 00/26] tty: drop low-latency workarounds
Date: Thu, 22 Apr 2021 12:09:47 +0200 [thread overview]
Message-ID: <YIFLa9I55aIRnJGY@kroah.com> (raw)
In-Reply-To: <20210421095509.3024-1-johan@kernel.org>
On Wed, Apr 21, 2021 at 11:54:43AM +0200, Johan Hovold wrote:
> The infamous low_latency behaviour of tty_flip_buffer_push(), which
> meant that data could be pushed to the line discipline immediately
> instead of being deferred to a work queue, was finally removed in 2014.
>
> Since then there's no need for drivers to keep hacks to temporarily drop
> the port lock during receive processing but this pattern has been
> reproduced in later added drivers nonetheless.
>
> Note that several of these workarounds were added by a series posted in
> 2013, which ended up being merged despite having completely nonsensical
> commit messages. As it turned out, it was just the RT patch set which
> effectively enabled the low_latency flag for serial drivers that did not
> handle it.
>
> There's of course nothing wrong releasing the port lock before calling
> tty_flip_buffer_push(), and some drivers still do after this series, but
> let's get rid of the completely unnecessary unlock-and-reacquire
> pattern.
Many thanks for cleaning up this old crud, all now applied.
greg k-h
prev parent reply other threads:[~2021-04-22 10:09 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-21 9:54 [PATCH 00/26] tty: drop low-latency workarounds Johan Hovold
2021-04-21 9:54 ` [PATCH 01/26] tty: mxser: drop low-latency workaround Johan Hovold
2021-04-22 5:59 ` Jiri Slaby
2021-04-21 9:54 ` [PATCH 02/26] serial: altera_jtaguart: " Johan Hovold
2021-04-21 10:03 ` Tobias Klauser
2021-04-21 9:54 ` [PATCH 03/26] serial: altera_uart: " Johan Hovold
2021-04-21 10:03 ` Tobias Klauser
2021-04-21 9:54 ` [PATCH 04/26] serial: amba-pl010: " Johan Hovold
2021-04-21 9:54 ` [PATCH 05/26] serial: amba-pl011: " Johan Hovold
2021-04-22 0:18 ` Linus Walleij
2021-04-21 9:54 ` [PATCH 06/26] serial: apbuart: " Johan Hovold
2021-04-21 9:54 ` [PATCH 07/26] serial: ar933x: " Johan Hovold
2021-04-21 9:54 ` [PATCH 08/26] serial: arc_uart: " Johan Hovold
2021-04-21 9:54 ` [PATCH 09/26] serial: atmel_serial: " Johan Hovold
2021-04-21 9:54 ` [PATCH 10/26] serial: bcm63xx: " Johan Hovold
2021-04-21 9:54 ` [PATCH 11/26] serial: icom: " Johan Hovold
2021-04-21 9:54 ` [PATCH 12/26] serial: lpc32xx_hs: " Johan Hovold
2021-04-21 9:54 ` [PATCH 13/26] serial: mcf: " Johan Hovold
2021-04-21 9:54 ` [PATCH 14/26] serial: meson: " Johan Hovold
2021-04-21 9:54 ` [PATCH 15/26] serial: mpc52xx_uart: " Johan Hovold
2021-04-21 9:54 ` [PATCH 16/26] serial: msm_serial: " Johan Hovold
2021-04-21 17:44 ` Bjorn Andersson
2021-04-21 9:55 ` [PATCH 17/26] serial: owl: " Johan Hovold
2021-04-21 9:55 ` [PATCH 18/26] serial: rda: " Johan Hovold
2021-04-21 9:55 ` [PATCH 19/26] serial: rp2: " Johan Hovold
2021-04-21 9:55 ` [PATCH 20/26] serial: sa1100: " Johan Hovold
2021-04-21 9:55 ` [PATCH 21/26] serial: txx9: " Johan Hovold
2021-04-21 9:55 ` [PATCH 22/26] serial: sifive: " Johan Hovold
2021-04-21 9:55 ` [PATCH 23/26] serial: sunsu: " Johan Hovold
2021-04-21 16:56 ` David Miller
2021-04-21 9:55 ` [PATCH 24/26] serial: timbuart: " Johan Hovold
2021-04-21 9:55 ` [PATCH 25/26] serial: vt8500: " Johan Hovold
2021-04-21 9:55 ` [PATCH 26/26] serial: xilinx_uartps: " Johan Hovold
2021-04-22 10:09 ` Greg Kroah-Hartman [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YIFLa9I55aIRnJGY@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=jirislaby@kernel.org \
--cc=johan@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.