From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: [PATCH 2/2] i2c: piix4: Use usleep_range() Date: Sat, 30 Dec 2017 08:50:58 -0800 Message-ID: <1514652658-6228-2-git-send-email-linux@roeck-us.net> References: <1514652658-6228-1-git-send-email-linux@roeck-us.net> Return-path: In-Reply-To: <1514652658-6228-1-git-send-email-linux@roeck-us.net> Sender: linux-kernel-owner@vger.kernel.org To: Wolfram Sang Cc: Jean Delvare , =?UTF-8?q?Zolt=C3=A1n=20B=C3=B6sz=C3=B6rm=C3=A9nyi?= , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Guenter Roeck List-Id: linux-i2c@vger.kernel.org The piix4 i2c driver is extremely slow. Replacing msleep() with usleep_range() increases its speed substantially. Signed-off-by: Guenter Roeck --- 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