Re: [PATCH] clocksource/drivers/time-armada-370-xp: Fix the clock reference

From: Gregory CLEMENT
Date: Wed Aug 10 2016 - 15:04:26 EST


Hi Thomas,

On mer., aoÃt 10 2016, Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> wrote:

> Hello,
>
> On Wed, 10 Aug 2016 10:09:08 +0200, Gregory CLEMENT wrote:
>> While converting the init function to return an error, the wrong clock
>> was get. This lead to wrong clock rate and slow down the kernel. For
>> example, before the patch a typical boot was around 15s after it was 1
>> minute slower.
>>
>> Fixes: 12549e27c63c ("clocksource/drivers/time-armada-370-xp: Convert init function to return error")
>>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/clocksource/time-armada-370-xp.c | 1 -
>> 1 file changed, 1 deletion(-)
>>
>> diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c
>> index 719b478d136e..3c39e6f45971 100644
>> --- a/drivers/clocksource/time-armada-370-xp.c
>> +++ b/drivers/clocksource/time-armada-370-xp.c
>> @@ -338,7 +338,6 @@ static int __init armada_xp_timer_init(struct device_node *np)
>> struct clk *clk = of_clk_get_by_name(np, "fixed");
>> int ret;
>>
>> - clk = of_clk_get(np, 0);
>
> I think to avoid this mistake, we should rewrite the code as:
>
> struct *clk;
> int ret;
>
> clk = of_clk_get_by_name(np, "fixed");
> if (IS_ERR(clk)) {
> ...
>
>

OK I can do it. it will be alos more coherent with the other _init
function.

Gregory

> Indeed, I find confusing a block that starts with error checking, and
> it's probably what lead to this of_clk_get() being added here.
>
> Thomas
> --
> Thomas Petazzoni, CTO, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com

--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com