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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).