Re: [PATCH v2] clocksource/drivers/tango_xtal: Add new timer for Tango SoCs

From: Mason
Date: Thu Oct 08 2015 - 09:15:13 EST


On 07/10/2015 18:03, Daniel Lezcano wrote:

> On 10/07/2015 03:17 PM, Marc Gonzalez wrote:
>
>> I'm also confused that you've replaced panic() with pr_err/return.
>> AFAIU, if I don't have a clocksource/sched_clock, the system is dead
>> in the water. Might as well stop there, and wait for the operator to
>> fix whatever needs fixing. (Several clksrc drivers do this.)
>
> Hmm, yeah that's true but also we have platforms with different
> clocksources, so we don't want to panic if the next clocksource will
> succeed. That's the logic behind not doing panic. There is some legacy
> code still using panic but that should be fixed.

There's so much legacy code lying around that it's really hard
to tell what the current best practices are :-(

> I don't know if your platform can fall under this category, but it would
> be a good practice to pr_err or pr_warn instead of panic in order to be
> consistent with the current direction in the recent drivers.

I think the system falls back to using the "jiffies clock" when
it doesn't find anything better? However, on my system, the
clockevent device is running at cpuclk/2, so once I add cpufreq
DFS into the mix, I don't think the "jiffies" clock is a very
good clocksource.

Anyway, updated patch is on the way.

Regards.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/