From: Guenter Roeck <linux@roeck-us.net>
To: Jean Delvare <jdelvare@suse.com>
Cc: Wolfram Sang <wsa@the-dreams.de>,
linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
Guenter Roeck <linux@roeck-us.net>
Subject: [PATCH v2 1/2] i2c: piix4: Use usleep_range()
Date: Mon, 26 Feb 2018 12:46:52 -0800 [thread overview]
Message-ID: <1519678013-32749-1-git-send-email-linux@roeck-us.net> (raw)
The piix4 i2c driver is extremely slow. Replacing msleep()
with usleep_range() increases its speed substantially.
Use sleep ranges similar to those used in the i2c-801 driver
to keep things simple.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: Changed timeout values for usleep_range()
2000/2000 -> 2000/2100
500/1000 -> 250/500
200/500 -> 250/500
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 462948e2c535..4c1f6aaec0fc 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -462,13 +462,13 @@ 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, 2100);
else
- msleep(1);
+ usleep_range(250, 500);
while ((++timeout < MAX_TIMEOUT) &&
((temp = inb_p(SMBHSTSTS)) & 0x01))
- msleep(1);
+ usleep_range(250, 500);
/* If the SMBus is still busy, we give up */
if (timeout == MAX_TIMEOUT) {
--
2.7.4
next reply other threads:[~2018-02-26 20:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-26 20:46 Guenter Roeck [this message]
2018-02-26 20:46 ` [PATCH v2 2/2] i2c: piix4: Use request_muxed_region Guenter Roeck
2018-02-26 20:52 ` Wolfram Sang
2018-02-26 21:34 ` Guenter Roeck
2018-02-26 21:43 ` Wolfram Sang
2018-02-26 21:44 ` Wolfram Sang
2018-02-26 22:28 ` Guenter Roeck
2018-02-26 22:28 ` Guenter Roeck
2018-03-01 10:57 ` Jean Delvare
2018-03-02 10:17 ` Wolfram Sang
2018-03-01 11:04 ` [PATCH v2 1/2] i2c: piix4: Use usleep_range() Jean Delvare
2018-03-02 10:17 ` Wolfram Sang
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