[patch 06/22] i2c-i801: Fix resume when PEC is used

Greg KH
2006-04-21T04:51:14Z

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Fix for bug #6395:
Fail to resume on Tecra M2 with ADM1032 and Intel 82801DBM

The BIOS of the Tecra M2 doesn't like it when it has to reboot or
resume after the i2c-i801 driver has left the SMBus in PEC mode.
I have a more complete fix for 2.6.17 but the simple approach of
leaving the SMBus in non-PEC mode after every transaction should do
for -stable. That's what the i2c-i801 driver was doing up to 2.6.15
(inclusive).

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

---
drivers/i2c/busses/i2c-i801.c | 5 +++++
1 file changed, 5 insertions(+)

--- linux-2.6.16.9.orig/drivers/i2c/busses/i2c-i801.c
+++ linux-2.6.16.9/drivers/i2c/busses/i2c-i801.c
@@ -478,6 +478,11 @@ static s32 i801_access(struct i2c_adapte
ret = i801_transaction();
}

+ /* Some BIOSes don't like it when PEC is enabled at reboot or resume
+ time, so we forcibly disable it after every transaction. */
+ if (hwpec)
+ outb_p(0, SMBAUXCTL);
+
if(block)
return ret;
if(ret)

--