Hi Santosh,
On 10/15/2010 7:48 AM, Shilimkar, Santosh wrote:
From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx]
Sent: Friday, October 15, 2010 3:44 AM
Rajendra Nayak<rnayak@xxxxxx> writes:
Do not skip the sysc programming in the hmwod framework based
on the cached value alone, since at times the module might have lost
context (due to the Powerdomain in which the module belongs
transitions to either Open Switch RET or OFF).
Shouldn't the driver for each IP be responsible for restoring it's
register contents after context loss, including it's SYSC?
Seems to me that if SYSC is lost, it means the driver's save/restore
is buggy.
I am glad you asked this question. I had a same argument with Benoit
that driver anyway does context save restore for other registers and
it can do SYSC as well.
But Benoit's point was that "sysconfig is a part of the PRCM located
in the IP, but this is purely TI implementation specific. The same
IP in another platform will not have this sysconfig entry. That's why
its important to hide them from the driver "
I don't have anything to add :-)
Thanks Santosh,
Benoit
This make sense too.
Signed-off-by: Rajendra Nayak<rnayak@xxxxxx>
Cc: Paul Walmsley<paul@xxxxxxxxx>
Cc: Benoit Cousson<b-cousson@xxxxxx>
Cc: Santosh Shilimkar<santosh.shilimkar@xxxxxx>
Cc: Kevin Hilman<khilman@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/mach-omap2/omap_hwmod.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-
omap2/omap_hwmod.c
index cb911d7..e57fe21 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -115,7 +115,10 @@ static void _write_sysconfig(u32 v, struct
omap_hwmod *oh)
/* XXX ensure module interface clock is up */
- if (oh->_sysc_cache != v) {
+ if ((oh->_sysc_cache != v) ||
+ /* Did the module go to off and loose context? */
+ (oh->_sysc_cache !=
+ omap_hwmod_readl(oh, oh->class->sysc->sysc_offs))) {
oh->_sysc_cache = v;
omap_hwmod_writel(v, oh, oh->class->sysc->sysc_offs);
}
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