[patch 01/29] i2c-pasemi: Fix NACK detection

Greg Kroah-Hartman
2007-11-20T18:26:18Z

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2.6.23-stable review patch. If anyone has any objections, please let us know.

------------------
From: Jean Delvare <khali@linux-fr.org>

patch be8a1f7cd4501c3b4b32543577a33aee6d2193ac in mainline.

Turns out we don't actually check the status to see if there was a
device out there to talk to, just if we had a timeout when doing so.

Add the proper check, so we don't falsly think there are devices
on the bus that are not there, etc.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/i2c/busses/i2c-pasemi.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/drivers/i2c/busses/i2c-pasemi.c
+++ b/drivers/i2c/busses/i2c-pasemi.c
@@ -51,6 +51,7 @@ struct pasemi_smbus {
#define MRXFIFO_DATA_M 0x000000ff

#define SMSTA_XEN 0x08000000
+#define SMSTA_MTN 0x00200000

#define CTL_MRR 0x00000400
#define CTL_MTR 0x00000200
@@ -98,6 +99,10 @@ static unsigned int pasemi_smb_waitready
status = reg_read(smbus, REG_SMSTA);
}

+ /* Got NACK? */
+ if (status & SMSTA_MTN)
+ return -ENXIO;
+
if (timeout < 0) {
dev_warn(&smbus->dev->dev, "Timeout, status 0x%08x\n", status);
reg_write(smbus, REG_SMSTA, status);

--