Hi Paul,
On 07/16/2012 01:38 PM, Paul Walmsley wrote:
> Hi Jon,
>
> On Mon, 16 Jul 2012, Jon Hunter wrote:
>
>> Yes I see that makes sense. However, patch #7 has already changed the
>> mapping of the flags. I had intended that patch #7 and #8 would be
>> applied together. However, I could see that patch #7 can be taken just
>> to eliminate using the SW_SLEEP state. So basically, what I am saying is
>> does patch #7 have any value without #8?
>
> Certainly not as much value as it had before. But my understanding, which
> is possibly incorrect, matches what you wrote in patch #7's description:
>
> "For OMAP4 devices, SW_SLEEP is equivalent to HW_AUTO and NO_SLEEP is
> equivalent to SW_WKUP. The only difference between HW_AUTO and SW_SLEEP
> for OMAP4 devices is that the PRM_IRQSTATUS_MPU.TRANSITION_ST interrupt
> status is set in case of SW_SLEEP transition, and not set in case of
> HW_AUTO transition."
>
> We don't use that PRM_IRQSTATUS_MPU.TRANSITION_ST interrupt bit. So if
> SW_SLEEP and HW_AUTO really have identical meanings otherwise, then I
> suppose we might as well use the one that does what we need with no
> extraneous side-effects? My recollection from a conversation with Benoît
> a few months ago was that this was his view as well.
>
>> That's fine with me. We can always workaround such issues by adding flags.
>>
>> I can give this a try this week and let you know how it goes.
>
> Okay, great. No rush on my account.
I have been testing your patch [1] on OMAP3 and found that the EMU
clock domain was not being disabled for two reasons.
1. When HWMOD attempts to disable the clock domain for OMAP2/3 devices
we simply return without doing anything. Not sure if it is safe to
remove this but I can do some more testing on OMAP2/3.
commit a0307bd539ecef976793679a1c4ff0d47b22c4bd
Author: Jon Hunter <jon-hunter@xxxxxx>
Date: Mon Jul 30 18:04:06 2012 -0500
ARM: OMAP2/3: Allow HWMOD to disable clock domains
Currently when HWMOD attempts to disable a clock domain on OMAP2/3 devices we
will return from the function clkdm_hwmod_disable() without actually disabling
the clock domain. Per the comment this is deliberate because initially HWMOD
OMAP2/3 devices did not support clock domains. However, clock domains are now
supported by HWMOD for these devices and so allow HWMOD to disable the clock
domains.
XXX - Tested on OMAP3430 beagle board, but needs more testing on OMAP2/3
diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index 011186f..8f7a941 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -1075,10 +1075,6 @@ int clkdm_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh)
*/
int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
{
- /* The clkdm attribute does not exist yet prior OMAP4 */
- if (cpu_is_omap24xx() || cpu_is_omap34xx())
- return 0;
-
/*
* XXX Rewrite this code to maintain a list of enabled
* downstream hwmods for debugging purposes?
2. I need to make the following changes to your patch. The change to
omap2_clkdm_clk_disable() was needed to get the EMU to turn off.
At the same time I thought we should make the same change to
omap2_clkdm_clk_enable().
diff --git a/arch/arm/mach-omap2/clockdomain2xxx_3xxx.c b/arch/arm/mach-omap2/clockdomain2xxx_3xxx.c
index 09385a9..c94b2fb 100644
--- a/arch/arm/mach-omap2/clockdomain2xxx_3xxx.c
+++ b/arch/arm/mach-omap2/clockdomain2xxx_3xxx.c
@@ -223,7 +223,8 @@ static int omap2_clkdm_clk_enable(struct clockdomain *clkdm)
_enable_hwsup(clkdm);
} else {
if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
- omap2_clkdm_wakeup(clkdm);
+ (cpu_is_omap24xx()) ? omap2_clkdm_wakeup(clkdm) :
+ omap3_clkdm_wakeup(clkdm);
}
return 0;
@@ -257,7 +258,8 @@ static int omap2_clkdm_clk_disable(struct clockdomain *clkdm)
_enable_hwsup(clkdm);
} else {
if (clkdm->flags & CLKDM_CAN_FORCE_SLEEP)
- omap2_clkdm_sleep(clkdm);
+ (cpu_is_omap24xx()) ? omap2_clkdm_sleep(clkdm) :
+ omap3_clkdm_sleep(clkdm);
}
I need to do more testing but wanted to give you this feedback and
get your comments.
Cheers
Jon
[1] http://marc.info/?l=linux-arm-kernel&m=134212814812557&w=2
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