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From: Daniel Kurtz <djkurtz@chromium.org>
To: Jean Delvare <khali@linux-fr.org>,
	Ben Dooks <ben-linux@fluff.org>,
	Wolfram Sang <w.sang@pengutronix.de>,
	Seth Heasley <seth.heasley@intel.com>
Cc: Olof Johansson <olof@lixom.net>,
	Benson Leung <bleung@chromium.org>,
	linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
	Daniel Kurtz <djkurtz@chromium.org>
Subject: [PATCH 2/8 v3] i2c: i801: optimize waiting for HWPEC to finish
Date: Wed, 27 Jun 2012 21:54:09 +0800	[thread overview]
Message-ID: <1340805255-8041-3-git-send-email-djkurtz@chromium.org> (raw)
In-Reply-To: <1340805255-8041-1-git-send-email-djkurtz@chromium.org>

When a transaction has finished (including the PEC), the SMBus controller
sets the INTR bit.
Slightly optimize the polling loop by reading status before the first
sleep.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
---
 drivers/i2c/busses/i2c-i801.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 51e11eb..8b74e1e 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -291,11 +291,11 @@ static void i801_wait_hwpec(struct i801_priv *priv)
 	int timeout = 0;
 	int status;
 
-	do {
+	status = inb_p(SMBHSTSTS(priv));
+	while ((!(status & SMBHSTSTS_INTR)) && (timeout++ < MAX_RETRIES)) {
 		usleep_range(250, 500);
 		status = inb_p(SMBHSTSTS(priv));
-	} while ((!(status & SMBHSTSTS_INTR))
-		 && (timeout++ < MAX_RETRIES));
+	}
 
 	if (timeout > MAX_RETRIES)
 		dev_dbg(&priv->pci_dev->dev, "PEC Timeout!\n");
-- 
1.7.7.3

  parent reply	other threads:[~2012-06-27 13:54 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-27 13:54 [PATCH 0/8 v3] i2c: i801: enable irq Daniel Kurtz
2012-06-27 13:54 ` [PATCH 1/8 v3] i2c: i801: refactor use of LAST_BYTE i801_block_transaction_byte_by_byte Daniel Kurtz
2012-06-27 14:39   ` Jean Delvare
2012-06-27 13:54 ` Daniel Kurtz [this message]
2012-06-27 14:58   ` [PATCH 2/8 v3] i2c: i801: optimize waiting for HWPEC to finish Jean Delvare
2012-06-27 13:54 ` [PATCH 3/8 v3] i2c: i801: check INTR after every transaction Daniel Kurtz
     [not found]   ` <1340805255-8041-4-git-send-email-djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2012-06-27 16:07     ` Jean Delvare
2012-06-28  7:51       ` Daniel Kurtz
     [not found]         ` <CAGS+omCoto4djKuZUooeD2A-szjrH4e9=YJCptR_raOdQ8g3-A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-06-28 11:36           ` Jean Delvare
     [not found]       ` <20120627180724.762f854a-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2012-07-01 21:20         ` Jean Delvare
     [not found]           ` <20120701232051.308c03d1-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2012-07-02  1:19             ` Daniel Kurtz
     [not found]               ` <CAGS+omDV_ynBL-PN0qmLmDRiHGbQFf+TwqC2-+KJY8zy9FDhrA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-07-02 10:08                 ` Jean Delvare
     [not found]                   ` <20120702120814.47d71bc5-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2012-07-02 15:16                     ` Jean Delvare
2012-06-27 13:54 ` [PATCH 4/8 v3] i2c: i801: check and return errors during byte-by-byte transfers Daniel Kurtz
     [not found]   ` <1340805255-8041-5-git-send-email-djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2012-06-27 16:51     ` Jean Delvare
2012-06-28  3:46       ` Daniel Kurtz
     [not found]         ` <CAGS+omDkhA=dP0JP=4huQEwJ4j6YqZWJ+mFsJv+eeGMBRpu5fQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-06-28  7:08           ` Jean Delvare
     [not found] ` <1340805255-8041-1-git-send-email-djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2012-06-27 13:54   ` [PATCH 5/8 v3] i2c: i801: rename some SMBHSTCNT bit constants Daniel Kurtz
     [not found]     ` <1340805255-8041-6-git-send-email-djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2012-06-27 17:01       ` Jean Delvare
2012-06-27 13:54 ` [PATCH 6/8 v3] i2c: i801: drop ENABLE_INT9 Daniel Kurtz
     [not found]   ` <1340805255-8041-7-git-send-email-djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2012-06-28  7:04     ` Jean Delvare
2012-06-27 13:54 ` [PATCH 7/8 v3] i2c: i801: enable irq for i801 smbus transactions Daniel Kurtz
     [not found]   ` <1340805255-8041-8-git-send-email-djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2012-07-04 15:48     ` Jean Delvare
2012-07-04 20:16     ` Jean Delvare
     [not found]       ` <20120704221600.416d4475-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2012-07-05  4:31         ` Daniel Kurtz
2012-07-05  8:10           ` Jean Delvare
2012-07-05 10:29             ` Jean Delvare
2012-07-06 10:28             ` Daniel Kurtz
     [not found]               ` <CAGS+omAgVLumYvOssHfdjELXixMdfRSxSj003xPzQ5v4h_D-mA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-07-06 11:55                 ` Jean Delvare
2012-06-27 13:54 ` [PATCH 8/8 v3] i2c: i801: enable irq for byte_by_byte transactions Daniel Kurtz
2012-07-05 14:46   ` Jean Delvare
     [not found]   ` <1340805255-8041-9-git-send-email-djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2012-07-08 11:53     ` Jean Delvare

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