On Sep 1, 2011, at 3:31 AM, Tudor Laurentiu wrote:

On 9/1/2011 9:27 AM, Kumar Gala wrote:

quoted

=20
On Aug 25, 2011, at 7:19 AM, Laurentiu Tudor wrote:
=20

quoted

Clearing the other TCR bits might break code that sets them (e.g. to =

setup

quoted

quoted

the watchdog or fixed interval timer) before start_cpu_decrementer() =

gets

quoted

quoted

called.

=20
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.

=20
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.

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

=20

quoted

quoted

Signed-off-by: Laurentiu Tudor<redacted>
---
arch/powerpc/kernel/time.c |    2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
=20

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 03b29a6..e8b5cdc 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c

@@ -721,7 +721,7 @@ void start_cpu_decrementer(void)

	mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
=20
	/* Enable decrementer interrupt */
-	mtspr(SPRN_TCR, TCR_DIE);
+	mtspr(SPRN_TCR, mfspr(SPRN_TCR) | TCR_DIE);
#endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
}
=20
--
1.7.1
=20
=20
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

=20
=20

=20
=20