[PATCH] powerpc/time: When starting the decrementer don't zero the other bits in TCR

Tudor Laurentiu Laurentiu.Tudor at freescale.com
Fri Sep 2 01:38:21 EST 2011

On 9/1/2011 4:56 PM, Kumar Gala wrote:
> On Sep 1, 2011, at 3:31 AM, Tudor Laurentiu wrote:
>> On 9/1/2011 9:27 AM, Kumar Gala wrote:
>>> On Aug 25, 2011, at 7:19 AM, Laurentiu Tudor wrote:
>>>> Clearing the other TCR bits might break code that sets them (e.g. to setup
>>>> the watchdog or fixed interval timer) before start_cpu_decrementer() gets
>>>> called.
>>> Can you be more specific about the case you're concerned about.  I'm not sure we want to leave the FIT enabled if it was previously.  Watchdog I could possibly see leaving alone.
>> My particular case was this: I was experimenting with having the watchdog enabled during the boot process, in case something goes wrong before the normal watchdog mechanism kicks in. That didn't work without making this modification.
>> Then, thinking that having a function start_cpu_decrementer() touching the other timers and not only the decrementer as its name implies might not be good. So I submitted this patch to the public mailing list to let the community decide if it's useful.
> So I think renaming the function is fine, and I think not touching the watchdog bits is also reasonable.  So if you update the patch along those lines I think we can push in.  I do want to make sure that the FIT is disabled as we dont expect it.

how about:

static void setup_cpu_timers()


> Probably add a comment about how care needs to be taken if the wathchdog is enable be firmware or a previous kernel.


More information about the Linuxppc-dev mailing list