From: Ian Campbell <icampbell@arcom.com>
Date: Wed, 10 Aug 2005 07:51:16 +0000 (+0100)
Subject: [PATCH] I2C: i2c-algo-pca -- gracefully handle a busy bus
X-Git-Tag: v2.6.14-rc1~752^2~39
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48edcb65ddcd93b6421831ad133599aacea9724a;p=linux-2.6

[PATCH] I2C: i2c-algo-pca -- gracefully handle a busy bus

I've been running with this patch for a while now, and while I've never
seen it trigger except with buggy hardware I think it is a cleaner way
to handle a busy bus. I had -EBUSY until about 10 minutes ago but -EIO
seems to be what most of the existing algo drivers will return in the
same circumstances.

Signed-off-by: Ian Campbell <icampbell@arcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index cc3a952401..ff2db0da44 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -187,12 +187,14 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
 	int numbytes = 0;
 	int state;
 	int ret;
+	int timeout = 100;
 
-	state = pca_status(adap);
-	if ( state != 0xF8 ) {
-		dev_dbg(&i2c_adap->dev, "bus is not idle. status is %#04x\n", state );
-		/* FIXME: what to do. Force stop ? */
-		return -EREMOTEIO;
+	while ((state = pca_status(adap)) != 0xf8 && timeout--) {
+		msleep(10);
+	}
+	if (state != 0xf8) {
+		dev_dbg(&i2c_adap->dev, "bus is not idle. status is %#04x\n", state);
+		return -EIO;
 	}
 
 	DEB1("{{{ XFER %d messages\n", num);