From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753324AbeBZUr1 (ORCPT ); Mon, 26 Feb 2018 15:47:27 -0500 Received: from mail-pf0-f196.google.com ([209.85.192.196]:34813 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752813AbeBZUq5 (ORCPT ); Mon, 26 Feb 2018 15:46:57 -0500 X-Google-Smtp-Source: AG47ELu/nw/eseSruAneZHJHzQ2n9WRimNxAsh8oKA5TbubzNwK5jtKlxcmHYU+DTRnVoYbQ/fv+HA== From: Guenter Roeck To: Jean Delvare Cc: Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Guenter Roeck Subject: [PATCH v2 1/2] i2c: piix4: Use usleep_range() Date: Mon, 26 Feb 2018 12:46:52 -0800 Message-Id: <1519678013-32749-1-git-send-email-linux@roeck-us.net> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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