From: Alexander Sverdlin alexander.sverdlin@siemens.com
The hack itself seems to be copied from Linux rti_wdt.c, but the WDT reset principle is different in U-Boot. While Linux relies on correct frequencies and timers and doesn't check the actual WDT counter value U-Boot driver seems to be more rubust: it does compare RTIDWDCNTR vs RTIDWDPRLD.
Now the root cause of the original motivation to manipulate the clock rate is said to be understood and fixed in Linux commit cae58516534e ("watchdog: rti_wdt: Set min_hw_heartbeat_ms to accommodate a safety margin") which simultaneously removed the hack itself.
While is fix part of the mentioned patch is neither applicable nor requied for the U-Boot driver just drop the hack setting WDT clock rate to 90% of the real rate. This has a nice effect that the WDT timeout is now as requested and not 10% shorter.
Signed-off-by: Alexander Sverdlin alexander.sverdlin@siemens.com --- drivers/watchdog/rti_wdt.c | 8 -------- 1 file changed, 8 deletions(-)
diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index 99168d0cad03..f806e24e53da 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -186,14 +186,6 @@ static int rti_wdt_probe(struct udevice *dev)
priv->clk_hz = clk_get_rate(&clk);
- /* - * If watchdog is running at 32k clock, it is not accurate. - * Adjust frequency down in this case so that it does not expire - * earlier than expected. - */ - if (priv->clk_hz < 32768) - priv->clk_hz = priv->clk_hz * 9 / 10; - return 0; }