Re: [PATCH RFC clocksource 2/5] clocksource: Retry clock read if long delays detected

[Rik van Riel]

On Tue, 2021-01-05 at 16:41 -0800, paulmck@xxxxxxxxxx wrote:
> 
> @@ -203,7 +204,6 @@ static void
> clocksource_watchdog_inject_delay(void)
>  		injectfail = inject_delay_run;
>  	if (!(++injectfail / inject_delay_run % inject_delay_freq)) {
>  		printk("%s(): Injecting delay.\n", __func__);
> -		injectfail = 0;
>  		for (i = 0; i < 2 * WATCHDOG_THRESHOLD / NSEC_PER_MSEC;
> i++)
>  			udelay(1000);

Wait, patch 1 just added that line?

Should patch 1 not add it and this
patch go without
this removal? :)

+               wdagain_nsec = clocksource_cyc2ns(delta, watchdog-
>mult, watchdog->shift);
+               if (wdagain_nsec < 0 || wdagain_nsec >
WATCHDOG_MAX_SKEW) {
+                       wderr_nsec = wdagain_nsec;
+                       if (nretries++ < max_read_retries)
+                               goto retry;
+               }

Given that clocksource_cyc2ns uses unsigned multiplication
followed by a right shift, do we need to test for <0?