diff mbox

[4/4] platform/x86: intel_pmc_ipc: Do not create iTCO watchdog when WDAT table exists

Message ID 20160913152336.75405-5-mika.westerberg@linux.intel.com (mailing list archive)
State RFC, archived
Headers show

Commit Message

Mika Westerberg Sept. 13, 2016, 3:23 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 an ACPI WDAT
table.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/platform/x86/intel_pmc_ipc.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Comments

Guenter Roeck Sept. 14, 2016, 8:04 p.m. UTC | #1
On Tue, Sep 13, 2016 at 06:23:36PM +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 an ACPI WDAT
> table.
> 
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/platform/x86/intel_pmc_ipc.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/platform/x86/intel_pmc_ipc.c b/drivers/platform/x86/intel_pmc_ipc.c
> index b86e1bcaa055..a511d518206b 100644
> --- a/drivers/platform/x86/intel_pmc_ipc.c
> +++ b/drivers/platform/x86/intel_pmc_ipc.c
> @@ -651,11 +651,15 @@ static int ipc_create_pmc_devices(void)
>  {
>  	int ret;
>  
> -	ret = ipc_create_tco_device();
> -	if (ret) {
> -		dev_err(ipcdev.dev, "Failed to add tco platform device\n");
> -		return ret;
> +	/* If we have ACPI based watchdog use that instead */
> +	if (!acpi_has_watchdog()) {
> +		ret = ipc_create_tco_device();
> +		if (ret) {
> +			dev_err(ipcdev.dev, "Failed to add tco platform device\n");
> +			return ret;
> +		}
>  	}
> +
>  	ret = ipc_create_punit_device();
>  	if (ret) {
>  		dev_err(ipcdev.dev, "Failed to add punit platform device\n");
> -- 
> 2.9.3
> 
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diff mbox

Patch

diff --git a/drivers/platform/x86/intel_pmc_ipc.c b/drivers/platform/x86/intel_pmc_ipc.c
index b86e1bcaa055..a511d518206b 100644
--- a/drivers/platform/x86/intel_pmc_ipc.c
+++ b/drivers/platform/x86/intel_pmc_ipc.c
@@ -651,11 +651,15 @@  static int ipc_create_pmc_devices(void)
 {
 	int ret;
 
-	ret = ipc_create_tco_device();
-	if (ret) {
-		dev_err(ipcdev.dev, "Failed to add tco platform device\n");
-		return ret;
+	/* If we have ACPI based watchdog use that instead */
+	if (!acpi_has_watchdog()) {
+		ret = ipc_create_tco_device();
+		if (ret) {
+			dev_err(ipcdev.dev, "Failed to add tco platform device\n");
+			return ret;
+		}
 	}
+
 	ret = ipc_create_punit_device();
 	if (ret) {
 		dev_err(ipcdev.dev, "Failed to add punit platform device\n");