Re: [PATCH v7 01/37] soc/tegra: pmc: Temporarily disable PMC state syncing

[Dmitry Osipenko <digetx@gmail.com>]

02.07.2021 02:26, Dmitry Osipenko пишет:
> Disable PMC state syncing in order to ensure that we won't break older
> kernels once device-trees will be updated with the addition of the power
> domains. Previously this was unnecessary because the plan was to make clk
> device that will attach to the domain for each clock, but the plan changed
> and now we're going make a better GENPD implementation that will require
> to update each device driver with the runtime PM and OPP support before
> we could safely enable the state syncing.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/soc/tegra/pmc.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> index ea62f84d1c8b..f63dfb2ca3f9 100644
> --- a/drivers/soc/tegra/pmc.c
> +++ b/drivers/soc/tegra/pmc.c
> @@ -360,6 +360,7 @@ struct tegra_pmc_soc {
>  	unsigned int num_pmc_clks;
>  	bool has_blink_output;
>  	bool has_usb_sleepwalk;
> +	bool supports_core_domain;
>  };
>  
>  /**
> @@ -3029,6 +3030,7 @@ static void tegra20_pmc_setup_irq_polarity(struct tegra_pmc *pmc,
>  }
>  
>  static const struct tegra_pmc_soc tegra20_pmc_soc = {
> +	.supports_core_domain = false,
>  	.num_powergates = ARRAY_SIZE(tegra20_powergates),
>  	.powergates = tegra20_powergates,
>  	.num_cpu_powergates = 0,
> @@ -3089,6 +3091,7 @@ static const char * const tegra30_reset_sources[] = {
>  };
>  
>  static const struct tegra_pmc_soc tegra30_pmc_soc = {
> +	.supports_core_domain = false,
>  	.num_powergates = ARRAY_SIZE(tegra30_powergates),
>  	.powergates = tegra30_powergates,
>  	.num_cpu_powergates = ARRAY_SIZE(tegra30_cpu_powergates),
> @@ -3145,6 +3148,7 @@ static const u8 tegra114_cpu_powergates[] = {
>  };
>  
>  static const struct tegra_pmc_soc tegra114_pmc_soc = {
> +	.supports_core_domain = false,
>  	.num_powergates = ARRAY_SIZE(tegra114_powergates),
>  	.powergates = tegra114_powergates,
>  	.num_cpu_powergates = ARRAY_SIZE(tegra114_cpu_powergates),
> @@ -3261,6 +3265,7 @@ static const struct pinctrl_pin_desc tegra124_pin_descs[] = {
>  };
>  
>  static const struct tegra_pmc_soc tegra124_pmc_soc = {
> +	.supports_core_domain = false,
>  	.num_powergates = ARRAY_SIZE(tegra124_powergates),
>  	.powergates = tegra124_powergates,
>  	.num_cpu_powergates = ARRAY_SIZE(tegra124_cpu_powergates),
> @@ -3386,6 +3391,7 @@ static const struct tegra_wake_event tegra210_wake_events[] = {
>  };
>  
>  static const struct tegra_pmc_soc tegra210_pmc_soc = {
> +	.supports_core_domain = false,
>  	.num_powergates = ARRAY_SIZE(tegra210_powergates),
>  	.powergates = tegra210_powergates,
>  	.num_cpu_powergates = ARRAY_SIZE(tegra210_cpu_powergates),
> @@ -3543,6 +3549,7 @@ static const struct tegra_wake_event tegra186_wake_events[] = {
>  };
>  
>  static const struct tegra_pmc_soc tegra186_pmc_soc = {
> +	.supports_core_domain = false,
>  	.num_powergates = 0,
>  	.powergates = NULL,
>  	.num_cpu_powergates = 0,
> @@ -3677,6 +3684,7 @@ static const struct tegra_wake_event tegra194_wake_events[] = {
>  };
>  
>  static const struct tegra_pmc_soc tegra194_pmc_soc = {
> +	.supports_core_domain = false,
>  	.num_powergates = 0,
>  	.powergates = NULL,
>  	.num_cpu_powergates = 0,
> @@ -3745,6 +3753,7 @@ static const char * const tegra234_reset_sources[] = {
>  };
>  
>  static const struct tegra_pmc_soc tegra234_pmc_soc = {
> +	.supports_core_domain = false,
>  	.num_powergates = 0,
>  	.powergates = NULL,
>  	.num_cpu_powergates = 0,
> @@ -3791,6 +3800,14 @@ static void tegra_pmc_sync_state(struct device *dev)
>  {
>  	int err;
>  
> +	/*
> +	 * Newer device-trees have power domains, but we need to prepare all
> +	 * device drivers with runtime PM and OPP support first, otherwise
> +	 * state syncing is unsafe.
> +	 */
> +	if (!pmc->soc->supports_core_domain)
> +		return;
> +
>  	/*
>  	 * Older device-trees don't have core PD, and thus, there are
>  	 * no dependencies that will block the state syncing. We shouldn't
> 

Thierry, could you please take this patch for 5.15? It should ease
further applying of the rest of the patches, thanks.