* [PATCH V2] [PM-WIP-OPP]: Fixing wrong target level being passed during Core DVFS.
@ 2010-02-23 17:03 Thara Gopinath
2010-02-23 18:37 ` Kevin Hilman
0 siblings, 1 reply; 2+ messages in thread
From: Thara Gopinath @ 2010-02-23 17:03 UTC (permalink / raw)
To: linux-omap; +Cc: Thara Gopinath, Kevin Hilman
As per the current implementaion (u8*)&target_level is being passed
to freq_to_opp in set_opp. This would result in updating just the first
8 bits of a u32 variable. Later target_level is passed to
resource_set_opp_level as a u32 parameter. This maens
a. Initially target_level was 0xabcdefgh.
b. freq_to_opp updates the lower eight bits of target_level
to 0xXX. Now target_level = 0xabcdefXX.
c. We pass 0xabcdefXX as target_level to resource_set_opp_level
when we want to pass just 0xXX.
This is leading to some corrupted bookkeeping later on in the
dvfs path.
This patch ensures that target_level passed to resource_set_opp_level
is actually the level that is intended by freq_to_opp API.
Signed-off-by: Thara Gopinath <thara@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
---
arch/arm/mach-omap2/resource34xx.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-omap2/resource34xx.c b/arch/arm/mach-omap2/resource34xx.c
index 3604a38..2c850a2 100644
--- a/arch/arm/mach-omap2/resource34xx.c
+++ b/arch/arm/mach-omap2/resource34xx.c
@@ -478,6 +478,7 @@ int set_opp(struct shared_resource *resp, u32 target_level)
/* uh uh.. no OPPs?? */
BUG_ON(IS_ERR(oppx));
+ target_level = 0;
ret = freq_to_opp((u8 *)&target_level, OPP_L3, req_l3_freq);
/* we dont expect this to fail */
BUG_ON(ret);
--
1.5.4.7
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH V2] [PM-WIP-OPP]: Fixing wrong target level being passed during Core DVFS.
2010-02-23 17:03 [PATCH V2] [PM-WIP-OPP]: Fixing wrong target level being passed during Core DVFS Thara Gopinath
@ 2010-02-23 18:37 ` Kevin Hilman
0 siblings, 0 replies; 2+ messages in thread
From: Kevin Hilman @ 2010-02-23 18:37 UTC (permalink / raw)
To: Thara Gopinath; +Cc: linux-omap
Thara Gopinath <thara@ti.com> writes:
> As per the current implementaion (u8*)&target_level is being passed
> to freq_to_opp in set_opp. This would result in updating just the first
> 8 bits of a u32 variable. Later target_level is passed to
> resource_set_opp_level as a u32 parameter. This maens
> a. Initially target_level was 0xabcdefgh.
> b. freq_to_opp updates the lower eight bits of target_level
> to 0xXX. Now target_level = 0xabcdefXX.
> c. We pass 0xabcdefXX as target_level to resource_set_opp_level
> when we want to pass just 0xXX.
> This is leading to some corrupted bookkeeping later on in the
> dvfs path.
>
> This patch ensures that target_level passed to resource_set_opp_level
> is actually the level that is intended by freq_to_opp API.
>
> Signed-off-by: Thara Gopinath <thara@ti.com>
> Cc: Kevin Hilman <khilman@deeprootsystems.com>
Thanks, applying to pm-wip-opp after cleaning up the formatting in the changelog
to be a little more readable.
Kevin
> ---
> arch/arm/mach-omap2/resource34xx.c | 1 +
> 1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/resource34xx.c b/arch/arm/mach-omap2/resource34xx.c
> index 3604a38..2c850a2 100644
> --- a/arch/arm/mach-omap2/resource34xx.c
> +++ b/arch/arm/mach-omap2/resource34xx.c
> @@ -478,6 +478,7 @@ int set_opp(struct shared_resource *resp, u32 target_level)
> /* uh uh.. no OPPs?? */
> BUG_ON(IS_ERR(oppx));
>
> + target_level = 0;
> ret = freq_to_opp((u8 *)&target_level, OPP_L3, req_l3_freq);
> /* we dont expect this to fail */
> BUG_ON(ret);
> --
> 1.5.4.7
^ permalink raw reply [flat|nested] 2+ messages in thread
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2010-02-23 17:03 [PATCH V2] [PM-WIP-OPP]: Fixing wrong target level being passed during Core DVFS Thara Gopinath
2010-02-23 18:37 ` Kevin Hilman
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