diff options
Diffstat (limited to 'drivers/watchdog/omap_wdt.c')
| -rw-r--r-- | drivers/watchdog/omap_wdt.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c index 7b1f429432..d724c964ed 100644 --- a/drivers/watchdog/omap_wdt.c +++ b/drivers/watchdog/omap_wdt.c @@ -53,16 +53,25 @@ void hw_watchdog_reset(void) { struct wd_timer *wdt = (struct wd_timer *)WDT_BASE; - /* wait for posted write to complete */ - while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WTGR) - ; + /* + * Somebody just triggered watchdog reset and write to WTGR register + * is in progress. It is resetting right now, no need to trigger it + * again + */ + if ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WTGR) + return; wdt_trgr_pattern = ~wdt_trgr_pattern; writel(wdt_trgr_pattern, &wdt->wdtwtgr); - /* wait for posted write to complete */ - while ((readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WTGR)) - ; + /* + * Don't wait for posted write to complete, i.e. don't check + * WDT_WWPS_PEND_WTGR bit in WWPS register. There is no writes to + * WTGR register outside of this func, and if entering it + * we see WDT_WWPS_PEND_WTGR bit set, it means watchdog reset + * was just triggered. This prevents us from wasting time in busy + * polling of WDT_WWPS_PEND_WTGR bit. + */ } static int omap_wdt_set_timeout(unsigned int timeout) |