Re: [PATCH v2 2/2] acpi_pm.c: check for monotonicity

[Jochen Voß]

Hi,

some minor comments:

2008/8/22 Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>:
> +       for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) {
> +               value1 = clocksource_acpi_pm.read();
> +               for (i = 0; i < 10000; i++) {
> +                       value2 = clocksource_acpi_pm.read();
> +                       if (value2 == value1)
> +                               continue;
> +                       if (value2 > value1)
> +                               good++;
> +                               break;
> +                       if ((value2 < value1) && ((value2) < 0xFFF))
The brackets arout value2 are not needed and look strange.

> +                               good++;
> +                               break;
> +                       printk(KERN_INFO "PM-Timer had inconsistent results:"
> +                              " 0x%#llx, 0x%#llx - aborting.\n",
> +                              value1, value2);
> +                       return -EINVAL;
> +               }
> +               udelay(300 * i);
300*10000 microseconds seems like a long time to me.  Is this the
intended maximal delay?

> +       }
> +
> +       if (good != ACPI_PM_MONOTONICITY_CHECKS) {
> +               printk(KERN_INFO "PM-Timer failed consistency check "
> +                      " (0x%#llx) - aborting.\n", value1);
> +               return -ENODEV;
If the inner loop runs out once, you alreay know that you will later
abort here.  Maybe move the check directly after the inner loop to
avoid the additional delay (10*10000*300 microseconds = 30 seconds) in
case of failure?

I hope this helps,
Jochen
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