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[v2,3/4] i2c: i801: Do not create iTCO watchdog when WDAT table exists

Message ID 20160920123054.195021-4-mika.westerberg@linux.intel.com (mailing list archive)
State Accepted, archived
Delegated to: Rafael Wysocki
Headers show

Commit Message

Mika Westerberg Sept. 20, 2016, 12:30 p.m. UTC 
ACPI WDAT table is the preferred way to use hardware watchdog over the
native iTCO_wdt. Windows only uses this table for its hardware watchdog
implementation so we should be relatively safe to trust it has been
validated by OEMs

Prevent iTCO watchdog creation if we detect that there is ACPI WDAT table.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/i2c/busses/i2c-i801.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Wolfram Sang Sept. 22, 2016, 5:47 p.m. UTC | #1 
On Tue, Sep 20, 2016 at 03:30:53PM +0300, Mika Westerberg wrote:
> ACPI WDAT table is the preferred way to use hardware watchdog over the
> native iTCO_wdt. Windows only uses this table for its hardware watchdog
> implementation so we should be relatively safe to trust it has been
> validated by OEMs
> 
> Prevent iTCO watchdog creation if we detect that there is ACPI WDAT table.
> 
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Acked-by: Wolfram Sang <wsa@the-dreams.de>
Wolfram Sang Sept. 22, 2016, 5:48 p.m. UTC | #2 
On Tue, Sep 20, 2016 at 03:30:53PM +0300, Mika Westerberg wrote:
> ACPI WDAT table is the preferred way to use hardware watchdog over the
> native iTCO_wdt. Windows only uses this table for its hardware watchdog
> implementation so we should be relatively safe to trust it has been
> validated by OEMs
> 
> Prevent iTCO watchdog creation if we detect that there is ACPI WDAT table.
> 
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>

BTW I assume this patch does not go via the i2c tree. Please tell me if
you think otherwise.
diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 5ef9b733d153..26298af73232 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -1486,7 +1486,9 @@  static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		priv->features |= FEATURE_IRQ;
 		priv->features |= FEATURE_SMBUS_PEC;
 		priv->features |= FEATURE_BLOCK_BUFFER;
-		priv->features |= FEATURE_TCO;
+		/* If we have ACPI based watchdog use that instead */
+		if (!acpi_has_watchdog())
+			priv->features |= FEATURE_TCO;
 		priv->features |= FEATURE_HOST_NOTIFY;
 		break;