Re: Integration branch base switchover to Tony's omap-for-linus branch

[Rajendra Nayak <rnayak@ti.com>]

Hi Paul,

On Wednesday 02 March 2011 03:03 AM, Paul Walmsley wrote:
> Hi Santosh
>
> On Tue, 1 Mar 2011, Santosh Shilimkar wrote:
>
>>> -----Original Message-----
>>> From: linux-omap-owner@vger.kernel.org [mailto:linux-omap-
>>> owner@vger.kernel.org] On Behalf Of Paul Walmsley
>>> Sent: Saturday, February 26, 2011 5:56 AM
>>> To: linux-omap@vger.kernel.org
>>> Subject: Integration branch base switchover to Tony's omap-for-linus
>>> branch
>>>
>>>
>>> Hi,
>>>
>>> this is a quick note for anyone using the integration-2.6.39 branch
>>> on
>>> git://git.pwsan.com/linux-2.6: I've switched the base over from
>>> mainline to Tony's omap-for-linus branch.
>>>
>>
>> I observed an issue when integrated omap-for-linus + your branch
>> + OMAP4 PM patches. After debugging this with Rajendra, it seems
>> that issue is seen only when static dependency between MPU
>> and L4PER clock-domain is cleared _and_ L4_PER clock-domain
>> is programmed to HW_SUP.
>>
>> Since the issue is observed with only I2C IP block from L4_PER
>> and none of the other modules are affected, the suspect is I2C
>> IP block. The hardware team is investigating this issue.
>>
>> So for now, to avoid this abort, there are two options
>> 	- Remove HW_SUP from L4_PER CD
>> 	- Keep MPU<->L4_PER static dependency.
>>
>> We tried both the options and they seems to work.
>> Which one you prefer till we have hardware root-cause
>> of this issue?
>
> Between the two alternatives you suggested, I'd prefer #1; but could you
> try forcing the I2C blocks to use software idle control instead and see if
> that fixes it without the need to change the clockdomains file?  Sample
> patch follows.  If that fixes it, it might be useful to know whether it is
> the HWMOD_SWSUP_SIDLE flag or HWMOD_NO_OCP_AUTOIDLE flag or both that is
> required.

Yes, it does seem to fix the issue also, and its the HWMOD_SWSUP_SIDLE
that apparently makes a difference. HWMOD_NO_OCP_AUTOIDLE alone does
not fix it.

Also some more testing showed up a lockup in suspend on OMAP4 which I
could narrow down to a similar case with GPT1. Either keeping the
staticdep between MPU and L4_WKUP _or_ forcing GPT1 to use software
idle control seems to help.

regards,
Rajendra

>
>
> - Paul
>
> From: Paul Walmsley<paul@pwsan.com>
> Date: Tue, 1 Mar 2011 14:11:31 -0700
> Subject: [PATCH] OMAP4: I2C hwmods: Test patch to attempt to narrow down crashes
>
> Put the I2C IP blocks into software-controlled idle to attempt to narrow down
> some crashes.
> ---
>   arch/arm/mach-omap2/omap_hwmod_44xx_data.c |    8 ++++----
>   1 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> index 79a8601..8415b97 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> @@ -2124,7 +2124,7 @@ static struct omap_hwmod_ocp_if *omap44xx_i2c1_slaves[] = {
>   static struct omap_hwmod omap44xx_i2c1_hwmod = {
>   	.name		= "i2c1",
>   	.class		=&omap44xx_i2c_hwmod_class,
> -	.flags		= HWMOD_INIT_NO_RESET,
> +	.flags		= HWMOD_INIT_NO_RESET | HWMOD_SWSUP_SIDLE | HWMOD_NO_OCP_AUTOIDLE,
>   	.mpu_irqs	= omap44xx_i2c1_irqs,
>   	.mpu_irqs_cnt	= ARRAY_SIZE(omap44xx_i2c1_irqs),
>   	.sdma_reqs	= omap44xx_i2c1_sdma_reqs,
> @@ -2177,7 +2177,7 @@ static struct omap_hwmod_ocp_if *omap44xx_i2c2_slaves[] = {
>   static struct omap_hwmod omap44xx_i2c2_hwmod = {
>   	.name		= "i2c2",
>   	.class		=&omap44xx_i2c_hwmod_class,
> -	.flags		= HWMOD_INIT_NO_RESET,
> +	.flags		= HWMOD_INIT_NO_RESET | HWMOD_SWSUP_SIDLE | HWMOD_NO_OCP_AUTOIDLE,
>   	.mpu_irqs	= omap44xx_i2c2_irqs,
>   	.mpu_irqs_cnt	= ARRAY_SIZE(omap44xx_i2c2_irqs),
>   	.sdma_reqs	= omap44xx_i2c2_sdma_reqs,
> @@ -2230,7 +2230,7 @@ static struct omap_hwmod_ocp_if *omap44xx_i2c3_slaves[] = {
>   static struct omap_hwmod omap44xx_i2c3_hwmod = {
>   	.name		= "i2c3",
>   	.class		=&omap44xx_i2c_hwmod_class,
> -	.flags		= HWMOD_INIT_NO_RESET,
> +	.flags		= HWMOD_INIT_NO_RESET | HWMOD_SWSUP_SIDLE | HWMOD_NO_OCP_AUTOIDLE,
>   	.mpu_irqs	= omap44xx_i2c3_irqs,
>   	.mpu_irqs_cnt	= ARRAY_SIZE(omap44xx_i2c3_irqs),
>   	.sdma_reqs	= omap44xx_i2c3_sdma_reqs,
> @@ -2283,7 +2283,7 @@ static struct omap_hwmod_ocp_if *omap44xx_i2c4_slaves[] = {
>   static struct omap_hwmod omap44xx_i2c4_hwmod = {
>   	.name		= "i2c4",
>   	.class		=&omap44xx_i2c_hwmod_class,
> -	.flags		= HWMOD_INIT_NO_RESET,
> +	.flags		= HWMOD_INIT_NO_RESET | HWMOD_SWSUP_SIDLE | HWMOD_NO_OCP_AUTOIDLE,
>   	.mpu_irqs	= omap44xx_i2c4_irqs,
>   	.mpu_irqs_cnt	= ARRAY_SIZE(omap44xx_i2c4_irqs),
>   	.sdma_reqs	= omap44xx_i2c4_sdma_reqs,