diff options
Diffstat (limited to 'drivers/watchdog/iTCO_wdt.c')
| -rw-r--r-- | drivers/watchdog/iTCO_wdt.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c index 35b358bcf94c..7672582fa407 100644 --- a/drivers/watchdog/iTCO_wdt.c +++ b/drivers/watchdog/iTCO_wdt.c @@ -82,6 +82,13 @@ #define TCO2_CNT(p) (TCOBASE(p) + 0x0a) /* TCO2 Control Register */ #define TCOv2_TMR(p) (TCOBASE(p) + 0x12) /* TCOv2 Timer Initial Value*/ +/* + * NMI_NOW is bit 8 of TCO1_CNT register + * Read/Write + * This bit is implemented as RW but has no effect on HW. + */ +#define NMI_NOW BIT(8) + /* internal variables */ struct iTCO_wdt_private { struct watchdog_device wddev; @@ -219,13 +226,23 @@ static int update_no_reboot_bit_cnt(void *priv, bool set) struct iTCO_wdt_private *p = priv; u16 val, newval; - val = inw(TCO1_CNT(p)); + /* + * writing back 1b1 to NMI_NOW of TCO1_CNT register + * causes NMI_NOW bit inversion what consequently does + * not allow to perform the register's value comparison + * properly. + * + * NMI_NOW bit masking for TCO1_CNT register values + * helps to avoid possible NMI_NOW bit inversions on + * following write operation. + */ + val = inw(TCO1_CNT(p)) & ~NMI_NOW; if (set) val |= BIT(0); else val &= ~BIT(0); outw(val, TCO1_CNT(p)); - newval = inw(TCO1_CNT(p)); + newval = inw(TCO1_CNT(p)) & ~NMI_NOW; /* make sure the update is successful */ return val != newval ? -EIO : 0; @@ -592,10 +609,8 @@ static int iTCO_wdt_probe(struct platform_device *pdev) watchdog_stop_on_reboot(&p->wddev); watchdog_stop_on_unregister(&p->wddev); ret = devm_watchdog_register_device(dev, &p->wddev); - if (ret != 0) { - dev_err(dev, "cannot register watchdog device (err=%d)\n", ret); + if (ret != 0) return ret; - } dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n", heartbeat, nowayout); |