[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>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index cc3a952401f2..ff2db0da4417 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);