Re: [linuxsh-dev] the watchdog overflow too fast.

[Jeremy S. <jas...@pa...>]

Spark.Kuo(*=A2=95=DA*a) wrote:

> Dear all:
>         I have ported the linux kernel 2.4.19 on my board using sh4=
 7751R.When i enable the watchdog,the board reboot immediately,someti=
mes the sh_wdt_ping() has entered several times, but sometimes not.
>         It seem to be that the watchdog overflow before the sh_wdt_=
ping() function.
>         i think that the sh_wdt_ping() function would set WTCNT to =
0x0 periodly,before the WDIOF_SETTIMEOUT settting.
>         but my watchdog reboot before the sh_wdt_ping() periodly re=
setting.
>         Has anyone some comments?

/* Yes, sh_wdt_ping() should clear WTCNT, but as a timer function it =
only does so when the timer pops, which I believe is dependent on the=
 kernel tick... and the longest setting for the watchdog is still
too fast for the normal 10ms tick.  Since you can't add bits to the c=
ounter, I'd guess all you can do is either slow down the base board c=
lock so the watchdog timeout is slow enough, or modify the kernel to
use a faster tick. */

--Jeremy Siegel