On Wed, Sep 20, 2017 at 03:00:17PM +0930, Andrew Jeffery wrote: > An unintended post-condition of probe() is that the watchdog is > disabled. This behaviour was introduced by an unnecessary write to the > control register to configure the hardware based on the devicetree. The > write is unnecessary because the cached control value that is > manipulated by the code parsing the devicetree is eventually written by > aspeed_wdt_enable(), which is when we care how the control register > should be configured. > > Remove the write to restore expected behaviour. > > Fixes: b7f0b8ad25f3 ("drivers/watchdog: ASPEED reference dev tree properties for config") > Signed-off-by: Andrew Jeffery <andrew@xxxxxxxx> > Reviewed-by: Joel Stanley <joel@xxxxxxxxx> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> > --- > drivers/watchdog/aspeed_wdt.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c > index 79cc766cd30f..6c6dd3f4c48d 100644 > --- a/drivers/watchdog/aspeed_wdt.c > +++ b/drivers/watchdog/aspeed_wdt.c > @@ -243,9 +243,13 @@ static int aspeed_wdt_probe(struct platform_device *pdev) > if (of_property_read_bool(np, "aspeed,external-signal")) > wdt->ctrl |= WDT_CTRL_WDT_EXT; > > - writel(wdt->ctrl, wdt->base + WDT_CTRL); > - > if (readl(wdt->base + WDT_CTRL) & WDT_CTRL_ENABLE) { > + /* > + * The watchdog is running, but invoke aspeed_wdt_start() to > + * write wdt->ctrl to WDT_CTRL to ensure the watchdog's > + * configuration conforms to the driver's expectations. > + * Primarily, ensure we're using the 1MHz clock source. > + */ > aspeed_wdt_start(&wdt->wdd); > set_bit(WDOG_HW_RUNNING, &wdt->wdd.status); > } -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html