From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> This ensures that the same value is read back as was eventually programmed when using seconds as accuracy. Even then, comparing the more precise heartbeat_ms against heartbeat in seconds will almost never provide a match and will needlessly raise a warning. Fix by comparing apples to apples. Tested in combination with U-Boot as watchdog starter. Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> --- To fully work, it also needs a U-Boot patch to add the same 10% margin to the clock frequency: https://patchwork.ozlabs.org/project/uboot/patch/9b3603a3-1bf4-eb57-c378-20d5c2accc34@xxxxxxxxxxx/ drivers/watchdog/rti_wdt.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index 117bc2a8eb0a..3ecd14e180fb 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -252,6 +252,7 @@ static int rti_wdt_probe(struct platform_device *pdev) } if (readl(wdt->base + RTIDWDCTRL) == WDENABLE_KEY) { + int preset_heartbeat; u32 time_left_ms; u64 heartbeat_ms; u32 wsize; @@ -262,11 +263,12 @@ static int rti_wdt_probe(struct platform_device *pdev) heartbeat_ms <<= WDT_PRELOAD_SHIFT; heartbeat_ms *= 1000; do_div(heartbeat_ms, wdt->freq); - if (heartbeat_ms != heartbeat * 1000) + preset_heartbeat = heartbeat_ms + 500; + preset_heartbeat /= 1000; + if (preset_heartbeat != heartbeat) dev_warn(dev, "watchdog already running, ignoring heartbeat config!\n"); - heartbeat = heartbeat_ms; - heartbeat /= 1000; + heartbeat = preset_heartbeat; wsize = readl(wdt->base + RTIWWDSIZECTRL); ret = rti_wdt_setup_hw_hb(wdd, wsize); -- 2.34.1
