08.04.2021 02:00, Sowjanya Komatineni пишет:
>
> On 4/7/21 3:57 PM, Sowjanya Komatineni wrote:
>>
>> On 4/7/21 2:36 PM, Dmitry Osipenko wrote:
>>> 07.04.2021 04:25, Sowjanya Komatineni пишет:
>>>> + if (!tegra->pdev->dev.pm_domain) {
>>>> + ret = tegra_powergate_sequence_power_up(TEGRA_POWERGATE_SATA,
>>>> + tegra->sata_clk,
>>>> + tegra->sata_rst);
>>>> + if (ret)
>>>> + goto disable_regulators;
>>>> + }
>>> Hi,
>>>
>>> Why you haven't added condition for tegra_powergate_power_off()? I think
>>> it should break GENPD and legacy PD API isn't not supported by T186
>>> at all.
>>>
>>> I'm also not sure whether the power up/down sequence is correct using
>>> GENPD.
>>>
>>> Moreover the driver doesn't support runtime PM, so GENPD should be
>>> always off?
>>
>> This driver already using legacy PD API's so thought its supported and
>> added power domain device check during powergate_sequence_power_up and
>> yes same should apply for powergate_power_off as well. But if legacy
>> PD is not supported by T186 then not sure why original driver even
>> using these API's.
>>
>>
> Sorry just took a look and driver supports T210 and prior tegra as well.
> T210 and prior supports legacy PD and this check is applicable for
> those. So we should add power domain device check for power off as well.
You could fix it with a follow up patch. Please try to test that
power-off works properly, at least try to unload the driver module and
re-load it.
> But for T186, we should have GENPD working once we add runtime PM
> support to driver.
>
> Preetham/Thierry, Can you confirm where SATA is un powergated prior to
> kernel?
>
>
>> But as RPM is not implemented yet for this driver, GENPD will be OFF
>> but SATA is not in power-gate by the time kernel starts and
>> functionally works.
>>
>> But with RPM implementation, I guess we can do proper power gate on/off.
>>
I now recalled that GENPD turns ON all domains by default and then turns
them OFF only when driver entered into the RPM-suspended state. This
means that AHCI GENPD should be always-ON for T186, which should be okay
if this doesn't break power sequences.
