Re: [PATCH v2 4/5] platform/x86: pmc_atom: Check state of PMC clocks on s2idle

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 1/8/24 12:27, Ilpo Järvinen wrote:
> On Sun, 7 Jan 2024, Hans de Goede wrote:
> 
>> Extend the s2idle check with checking that none of the PMC clocks
>> is in the forced-on state. If one of the clocks is in forced on
>> state then S0i3 cannot be reached.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>> Changes in v2:
>> - Drop the PMC_CLK_* defines these are defined in
>>   include/linux/platform_data/x86/pmc_atom.h now
>> - Drop duplicated "pmc_atom: " prefix from pr_err() message
>> ---
>>  drivers/platform/x86/pmc_atom.c | 11 +++++++++++
>>  1 file changed, 11 insertions(+)
>>
>> diff --git a/drivers/platform/x86/pmc_atom.c b/drivers/platform/x86/pmc_atom.c
>> index 81ad66117365..d04f635c4075 100644
>> --- a/drivers/platform/x86/pmc_atom.c
>> +++ b/drivers/platform/x86/pmc_atom.c
>> @@ -477,6 +477,7 @@ static void pmc_s2idle_check(void)
>>  	u32 func_dis, func_dis_2;
>>  	u32 d3_sts_0, d3_sts_1;
>>  	u32 false_pos_sts_0, false_pos_sts_1;
>> +	int i;
>>  
>>  	func_dis = pmc_reg_read(pmc, PMC_FUNC_DIS);
>>  	func_dis_2 = pmc_reg_read(pmc, PMC_FUNC_DIS_2);
>> @@ -504,6 +505,16 @@ static void pmc_s2idle_check(void)
>>  
>>  	/* High part */
>>  	pmc_dev_state_check(d3_sts_1, m->d3_sts_1, func_dis_2, m->func_dis_2, false_pos_sts_1);
>> +
>> +	/* Check PMC clocks */
> 
> Kind of obvious comment, how about:
> 
> 	/* Check PMC clocks don't prevent S0i3 */
> 
> Or
> 
> 	/* Forced-on PMC clock prevents S0i3? */
> 
> ?

Good point. I have gone with the "Forced-on PMC clock prevents S0i3"
comment.

Regards,

Hans


> 
>> +	for (i = 0; i < PMC_CLK_NUM; i++) {
>> +		u32 ctl = pmc_reg_read(pmc, PMC_CLK_CTL_OFFSET + 4 * i);
>> +
>> +		if ((ctl & PMC_MASK_CLK_CTL) != PMC_CLK_CTL_FORCE_ON)
>> +			continue;
>> +
>> +		pr_err("clock %d is ON prior to freeze (ctl 0x%08x)\n", i, ctl);
>> +	}
>>  }
>>  
>>  static struct acpi_s2idle_dev_ops pmc_s2idle_ops = {
>>
> 
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> 
>