All of lore.kernel.org
 help / color / mirror / Atom feed
From: Joe Perches <joe@perches.com>
To: Guenter Roeck <linux@roeck-us.net>, Jean Delvare <jdelvare@suse.de>
Cc: "Wolfram Sang" <wsa@the-dreams.de>,
	"Zoltán Böszörményi" <zboszor@pr.hu>,
	linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] i2c: piix4: Use usleep_range()
Date: Mon, 12 Feb 2018 13:35:26 -0800	[thread overview]
Message-ID: <1518471326.22190.8.camel@perches.com> (raw)
In-Reply-To: <20180212205959.GA27573@roeck-us.net>

On Mon, 2018-02-12 at 12:59 -0800, Guenter Roeck wrote:
> On Mon, Feb 12, 2018 at 11:53:36AM +0100, Jean Delvare wrote:
> > On Sat, 30 Dec 2017 08:50:58 -0800, Guenter Roeck wrote:
> > > The piix4 i2c driver is extremely slow. Replacing msleep()
> > > with usleep_range() increases its speed substantially.
[]
> > > diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
[]
> > > @@ -467,13 +467,13 @@ static int piix4_transaction(struct i2c_adapter *piix4_adapter)
> > >  
> > >  	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
> > >  	if (srvrworks_csb5_delay) /* Extra delay for SERVERWORKS_CSB5 */
> > > -		msleep(2);
> > > +		usleep_range(2000, 2000);

usleep_range without a range isn't particularly useful.
Perhaps a 100 uSec range would allow better scheduling.

		usleep_range(2000, 2100);

  reply	other threads:[~2018-02-12 21:35 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-30 16:50 [PATCH 1/2] i2c: piix4: Use request_muxed_region Guenter Roeck
2017-12-30 16:50 ` [PATCH 2/2] i2c: piix4: Use usleep_range() Guenter Roeck
2018-02-11 20:12   ` [2/2] " Guenter Roeck
2018-02-12 10:53   ` [PATCH 2/2] " Jean Delvare
2018-02-12 20:59     ` Guenter Roeck
2018-02-12 21:35       ` Joe Perches [this message]
2018-02-12 22:22     ` Guenter Roeck
2018-02-14 14:44       ` Jean Delvare
2018-02-26 19:56     ` Wolfram Sang
2018-02-22  3:59   ` Andrew Cooks
2018-02-11 20:11 ` [1/2] i2c: piix4: Use request_muxed_region Guenter Roeck
2018-02-12 10:10 ` [PATCH 1/2] " Jean Delvare
2018-02-12 18:51   ` Guenter Roeck
2018-02-13 11:48     ` Böszörményi Zoltán
2018-02-13 14:11       ` Guenter Roeck
2018-02-14 14:23     ` Jean Delvare
2018-02-26 19:55       ` Wolfram Sang
2018-02-26 20:37         ` Guenter Roeck

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=1518471326.22190.8.camel@perches.com \
    --to=joe@perches.com \
    --cc=jdelvare@suse.de \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@roeck-us.net \
    --cc=wsa@the-dreams.de \
    --cc=zboszor@pr.hu \
    /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.