linux-i2c.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Guenter Roeck <linux@roeck-us.net>
To: Wolfram Sang <wsa@the-dreams.de>
Cc: "Jean Delvare" <jdelvare@suse.com>,
	"Zoltán Böszörményi" <zboszor@pr.hu>,
	linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Guenter Roeck" <linux@roeck-us.net>
Subject: [PATCH 2/2] i2c: piix4: Use usleep_range()
Date: Sat, 30 Dec 2017 08:50:58 -0800	[thread overview]
Message-ID: <1514652658-6228-2-git-send-email-linux@roeck-us.net> (raw)
In-Reply-To: <1514652658-6228-1-git-send-email-linux@roeck-us.net>

The piix4 i2c driver is extremely slow. Replacing msleep()
with usleep_range() increases its speed substantially.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/i2c/busses/i2c-piix4.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 78dd5951d6e7..52a8b1c5c110 100644
--- 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);
 	else
-		msleep(1);
+		usleep_range(500, 1000);
 
 	while ((++timeout < MAX_TIMEOUT) &&
 	       ((temp = inb_p(SMBHSTSTS)) & 0x01))
-		msleep(1);
+		usleep_range(200, 500);
 
 	/* If the SMBus is still busy, we give up */
 	if (timeout == MAX_TIMEOUT) {
-- 
2.7.4

  reply	other threads:[~2017-12-30 16:50 UTC|newest]

Thread overview: 17+ 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 ` Guenter Roeck [this message]
2018-02-11 20:12   ` [2/2] i2c: piix4: Use usleep_range() 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
2018-02-12 22:22     ` Guenter Roeck
2018-02-14 14:44       ` Jean Delvare
2018-02-26 19:56     ` Wolfram Sang
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=1514652658-6228-2-git-send-email-linux@roeck-us.net \
    --to=linux@roeck-us.net \
    --cc=jdelvare@suse.com \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --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 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).