* [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack()
@ 2008-03-17 14:47 Yoichi Yuasa
2008-03-17 14:49 ` [PATCH 2/2][MIPS] add irq_disable_hazard() before c0_compare_int_pending() Yoichi Yuasa
2008-03-17 16:16 ` [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack() Ralf Baechle
0 siblings, 2 replies; 6+ messages in thread
From: Yoichi Yuasa @ 2008-03-17 14:47 UTC (permalink / raw)
To: Ralf Baechle; +Cc: yoichi_yuasa, linux-mips
VR41xx, CP0 hazard is necessary between read_c0_count() and write_c0_compare().
However, the problem can be solved by replacing this by c0_timer_ack().
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
diff -pruN -X /home/yuasa/Memo/dontdiff linux-orig/arch/mips/kernel/cevt-r4k.c linux/arch/mips/kernel/cevt-r4k.c
--- linux-orig/arch/mips/kernel/cevt-r4k.c 2008-03-11 10:10:09.453835304 +0900
+++ linux/arch/mips/kernel/cevt-r4k.c 2008-03-12 16:35:42.911447048 +0900
@@ -186,7 +186,7 @@ static int c0_compare_int_usable(void)
* IP7 already pending? Try to clear it by acking the timer.
*/
if (c0_compare_int_pending()) {
- write_c0_compare(read_c0_count());
+ c0_timer_ack();
irq_disable_hazard();
if (c0_compare_int_pending())
return 0;
@@ -198,7 +198,7 @@ static int c0_compare_int_usable(void)
write_c0_compare(cnt);
irq_disable_hazard();
if ((int)(read_c0_count() - cnt) < 0)
- break;
+ break;
/* increase delta if the timer was already expired */
}
@@ -208,7 +208,7 @@ static int c0_compare_int_usable(void)
if (!c0_compare_int_pending())
return 0;
- write_c0_compare(read_c0_count());
+ c0_timer_ack();
irq_disable_hazard();
if (c0_compare_int_pending())
return 0;
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 2/2][MIPS] add irq_disable_hazard() before c0_compare_int_pending()
2008-03-17 14:47 [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack() Yoichi Yuasa
@ 2008-03-17 14:49 ` Yoichi Yuasa
2008-03-17 16:16 ` [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack() Ralf Baechle
1 sibling, 0 replies; 6+ messages in thread
From: Yoichi Yuasa @ 2008-03-17 14:49 UTC (permalink / raw)
To: Ralf Baechle; +Cc: yoichi_yuasa, linux-mips
Add irq_disable_hazard() before c0_compare_int_pending().
VR41xx sometime fails at this point.
It can be fix this patch.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
diff -pruN -X /home/yuasa/Memo/dontdiff linux-orig/arch/mips/kernel/cevt-r4k.c linux/arch/mips/kernel/cevt-r4k.c
--- linux-orig/arch/mips/kernel/cevt-r4k.c 2008-03-12 16:37:31.317624763 +0900
+++ linux/arch/mips/kernel/cevt-r4k.c 2008-03-12 16:37:39.894113510 +0900
@@ -205,6 +205,7 @@ static int c0_compare_int_usable(void)
while ((int)(read_c0_count() - cnt) <= 0)
; /* Wait for expiry */
+ irq_disable_hazard();
if (!c0_compare_int_pending())
return 0;
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack()
2008-03-17 14:47 [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack() Yoichi Yuasa
2008-03-17 14:49 ` [PATCH 2/2][MIPS] add irq_disable_hazard() before c0_compare_int_pending() Yoichi Yuasa
@ 2008-03-17 16:16 ` Ralf Baechle
2008-03-18 4:47 ` Yoichi Yuasa
1 sibling, 1 reply; 6+ messages in thread
From: Ralf Baechle @ 2008-03-17 16:16 UTC (permalink / raw)
To: Yoichi Yuasa; +Cc: linux-mips
On Mon, Mar 17, 2008 at 11:47:40PM +0900, Yoichi Yuasa wrote:
> VR41xx, CP0 hazard is necessary between read_c0_count() and write_c0_compare().
Interesting. I wonder why you need this patch but nobody else?
Ralf
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack()
2008-03-17 16:16 ` [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack() Ralf Baechle
@ 2008-03-18 4:47 ` Yoichi Yuasa
2008-03-18 13:27 ` Ralf Baechle
0 siblings, 1 reply; 6+ messages in thread
From: Yoichi Yuasa @ 2008-03-18 4:47 UTC (permalink / raw)
To: Ralf Baechle; +Cc: yoichi_yuasa, linux-mips
Hi Ralf,
On Mon, 17 Mar 2008 16:16:35 +0000
Ralf Baechle <ralf@linux-mips.org> wrote:
> On Mon, Mar 17, 2008 at 11:47:40PM +0900, Yoichi Yuasa wrote:
>
> > VR41xx, CP0 hazard is necessary between read_c0_count() and write_c0_compare().
>
> Interesting. I wonder why you need this patch but nobody else?
Three NOP are necessary on the TB0287(VR4131 board).
Yoichi
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack()
2008-03-18 4:47 ` Yoichi Yuasa
@ 2008-03-18 13:27 ` Ralf Baechle
2008-03-19 7:38 ` [PATCH][MIPS] add CP0 hazard to CP0 compare register accesses Yoichi Yuasa
0 siblings, 1 reply; 6+ messages in thread
From: Ralf Baechle @ 2008-03-18 13:27 UTC (permalink / raw)
To: Yoichi Yuasa; +Cc: linux-mips
On Tue, Mar 18, 2008 at 01:47:20PM +0900, Yoichi Yuasa wrote:
> On Mon, 17 Mar 2008 16:16:35 +0000
> Ralf Baechle <ralf@linux-mips.org> wrote:
>
> > On Mon, Mar 17, 2008 at 11:47:40PM +0900, Yoichi Yuasa wrote:
> >
> > > VR41xx, CP0 hazard is necessary between read_c0_count() and write_c0_compare().
> >
> > Interesting. I wonder why you need this patch but nobody else?
>
> Three NOP are necessary on the TB0287(VR4131 board).
That much was obvious from your patch. I was more wondering about this
change:
- write_c0_compare(read_c0_count());
+ c0_timer_ack();
c0_timer_ack is defined as
static void c0_timer_ack(void)
{
write_c0_compare(read_c0_compare());
}
so your patch does a functional change there - even though it should not
actually matter. So I was wondering if for some reason you need that
change.
Just interested - it looks a bit cleaner so I'm leaning to apply this
change anyway.
Ralf
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH][MIPS] add CP0 hazard to CP0 compare register accesses
2008-03-18 13:27 ` Ralf Baechle
@ 2008-03-19 7:38 ` Yoichi Yuasa
0 siblings, 0 replies; 6+ messages in thread
From: Yoichi Yuasa @ 2008-03-19 7:38 UTC (permalink / raw)
To: Ralf Baechle; +Cc: yoichi_yuasa, linux-mips
Hi,
On Tue, 18 Mar 2008 13:27:09 +0000
Ralf Baechle <ralf@linux-mips.org> wrote:
> On Tue, Mar 18, 2008 at 01:47:20PM +0900, Yoichi Yuasa wrote:
>
> > On Mon, 17 Mar 2008 16:16:35 +0000
> > Ralf Baechle <ralf@linux-mips.org> wrote:
> >
> > > On Mon, Mar 17, 2008 at 11:47:40PM +0900, Yoichi Yuasa wrote:
> > >
> > > > VR41xx, CP0 hazard is necessary between read_c0_count() and write_c0_compare().
> > >
> > > Interesting. I wonder why you need this patch but nobody else?
> >
> > Three NOP are necessary on the TB0287(VR4131 board).
>
> That much was obvious from your patch. I was more wondering about this
> change:
>
> - write_c0_compare(read_c0_count());
> + c0_timer_ack();
>
> c0_timer_ack is defined as
>
> static void c0_timer_ack(void)
> {
> write_c0_compare(read_c0_compare());
> }
>
> so your patch does a functional change there - even though it should not
> actually matter. So I was wondering if for some reason you need that
> change.
OK, update my patch.
Two patches have been brought together in one.
How about this?
VR41xx, CP0 hazard is necessary between read_c0_count() and write_c0_compare()
(or read_c0_cause()).
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
diff -pruN -X /home/yuasa/Memo/dontdiff linux-orig/arch/mips/kernel/cevt-r4k.c linux/arch/mips/kernel/cevt-r4k.c
--- linux-orig/arch/mips/kernel/cevt-r4k.c 2008-03-19 11:35:53.017749179 +0900
+++ linux/arch/mips/kernel/cevt-r4k.c 2008-03-19 16:31:29.617938142 +0900
@@ -186,7 +186,9 @@ static int c0_compare_int_usable(void)
* IP7 already pending? Try to clear it by acking the timer.
*/
if (c0_compare_int_pending()) {
- write_c0_compare(read_c0_count());
+ cnt = read_c0_count();
+ back_to_back_c0_hazard();
+ write_c0_compare(cnt);
irq_disable_hazard();
if (c0_compare_int_pending())
return 0;
@@ -205,10 +207,13 @@ static int c0_compare_int_usable(void)
while ((int)(read_c0_count() - cnt) <= 0)
; /* Wait for expiry */
+ back_to_back_c0_hazard();
if (!c0_compare_int_pending())
return 0;
- write_c0_compare(read_c0_count());
+ cnt = read_c0_count();
+ back_to_back_c0_hazard();
+ write_c0_compare(cnt);
irq_disable_hazard();
if (c0_compare_int_pending())
return 0;
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2008-03-19 7:38 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-03-17 14:47 [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack() Yoichi Yuasa
2008-03-17 14:49 ` [PATCH 2/2][MIPS] add irq_disable_hazard() before c0_compare_int_pending() Yoichi Yuasa
2008-03-17 16:16 ` [PATCH 1/2][MIPS] replace c0_compare acknowledge by c0_timer_ack() Ralf Baechle
2008-03-18 4:47 ` Yoichi Yuasa
2008-03-18 13:27 ` Ralf Baechle
2008-03-19 7:38 ` [PATCH][MIPS] add CP0 hazard to CP0 compare register accesses Yoichi Yuasa
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