watchdog: iTCO_wdt: Make ICH_RES_IO_SMI optional

commit e42b0c24389d5a1602e77db4f6def0d5a19e3e43 upstream.

The iTCO_wdt driver only needs ICH_RES_IO_SMI I/O resource when either
turn_SMI_watchdog_clear_off module parameter is set to match ->iTCO_version
(or higher), and when legacy iTCO_vendorsupport is set. Modify the driver
so that ICH_RES_IO_SMI is optional if the two conditions are not met.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index 156360e..e707c47 100644 (file)
--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -459,13 +459,25 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
        if (!p->tco_res)
                return -ENODEV;
 
-       p->smi_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_SMI);
-       if (!p->smi_res)
-               return -ENODEV;
-
        p->iTCO_version = pdata->version;
        p->pci_dev = to_pci_dev(dev->parent);
 
+       p->smi_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_SMI);
+       if (p->smi_res) {
+               /* The TCO logic uses the TCO_EN bit in the SMI_EN register */
+               if (!devm_request_region(dev, p->smi_res->start,
+                                        resource_size(p->smi_res),
+                                        pdev->name)) {
+                       pr_err("I/O address 0x%04llx already in use, device disabled\n",
+                              (u64)SMI_EN(p));
+                       return -EBUSY;
+               }
+       } else if (iTCO_vendorsupport ||
+                  turn_SMI_watchdog_clear_off >= p->iTCO_version) {
+               pr_err("SMI I/O resource is missing\n");
+               return -ENODEV;
+       }
+
        iTCO_wdt_no_reboot_bit_setup(p, pdata);
 
        /*
@@ -492,14 +504,6 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
        /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
        p->update_no_reboot_bit(p->no_reboot_priv, true);
 
-       /* The TCO logic uses the TCO_EN bit in the SMI_EN register */
-       if (!devm_request_region(dev, p->smi_res->start,
-                                resource_size(p->smi_res),
-                                pdev->name)) {
-               pr_err("I/O address 0x%04llx already in use, device disabled\n",
-                      (u64)SMI_EN(p));
-               return -EBUSY;
-       }
        if (turn_SMI_watchdog_clear_off >= p->iTCO_version) {
                /*
                 * Bit 13: TCO_EN -> 0