linux-kernel - Re: [PATCH 2/3] nvmem: qfprom: sc7280: Handle the additional power-domains vote

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Date:   Tue, 27 Jul 2021 17:50:22 +0530
From:   Rajendra Nayak <rnayak@...eaurora.org>
To:     Doug Anderson <dianders@...omium.org>
Cc:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>, LKML <linux-kernel@...r.kernel.org>,
        "Ravi Kumar Bokka (Temp)" <rbokka@...eaurora.org>
Subject: Re: [PATCH 2/3] nvmem: qfprom: sc7280: Handle the additional
 power-domains vote


On 7/23/2021 10:13 PM, Doug Anderson wrote:
> Hi,
> 
> On Wed, Jul 21, 2021 at 10:29 PM Rajendra Nayak <rnayak@...eaurora.org> wrote:
>>
>> On sc7280, to reliably blow fuses, we need an additional vote
>> on max performance state of 'MX' power-domain.
>> Add support for power-domain performance state voting in the
>> driver.
>>
>> Signed-off-by: Rajendra Nayak <rnayak@...eaurora.org>
>> ---
>>   drivers/nvmem/qfprom.c | 22 ++++++++++++++++++++++
>>   1 file changed, 22 insertions(+)
>>
>> diff --git a/drivers/nvmem/qfprom.c b/drivers/nvmem/qfprom.c
>> index 81fbad5..4d0a576 100644
>> --- a/drivers/nvmem/qfprom.c
>> +++ b/drivers/nvmem/qfprom.c
>> @@ -12,6 +12,8 @@
>>   #include <linux/mod_devicetable.h>
>>   #include <linux/nvmem-provider.h>
>>   #include <linux/platform_device.h>
>> +#include <linux/pm_domain.h>
>> +#include <linux/pm_runtime.h>
>>   #include <linux/property.h>
>>   #include <linux/regulator/consumer.h>
>>
>> @@ -149,6 +151,11 @@ static void qfprom_disable_fuse_blowing(const struct qfprom_priv *priv,
>>          if (ret)
>>                  dev_warn(priv->dev, "Failed to set 0 voltage (ignoring)\n");
>>
>> +       if (priv->dev->pm_domain) {
>> +               dev_pm_genpd_set_performance_state(priv->dev, 0);
>> +               pm_runtime_put(priv->dev);
>> +       }
>> +
>>          ret = regulator_disable(priv->vcc);
>>          if (ret)
>>                  dev_warn(priv->dev, "Failed to disable regulator (ignoring)\n");
>> @@ -212,6 +219,16 @@ static int qfprom_enable_fuse_blowing(const struct qfprom_priv *priv,
>>                  goto err_clk_rate_set;
>>          }
>>
>> +       if (priv->dev->pm_domain) {
>> +               ret = pm_runtime_get_sync(priv->dev);
>> +               if (ret < 0) {
>> +                       pm_runtime_put_noidle(priv->dev);
>> +                       dev_err(priv->dev, "Failed to enable power-domain\n");
>> +                       goto err_reg_enable;
>> +               }
>> +               dev_pm_genpd_set_performance_state(priv->dev, INT_MAX);
>> +       }
>> +
>>          old->timer_val = readl(priv->qfpconf + QFPROM_BLOW_TIMER_OFFSET);
>>          old->accel_val = readl(priv->qfpconf + QFPROM_ACCEL_OFFSET);
>>          writel(priv->soc_data->qfprom_blow_timer_value,
>> @@ -221,6 +238,8 @@ static int qfprom_enable_fuse_blowing(const struct qfprom_priv *priv,
>>
>>          return 0;
>>
>> +err_reg_enable:
>> +       regulator_disable(priv->vcc);
>>   err_clk_rate_set:
>>          clk_set_rate(priv->secclk, old->clk_rate);
>>   err_clk_prepared:
>> @@ -420,6 +439,9 @@ static int qfprom_probe(struct platform_device *pdev)
>>                          econfig.reg_write = qfprom_reg_write;
>>          }
>>
>> +       if (dev->pm_domain)
>> +               pm_runtime_enable(dev);
>> +
> 
> Where is the matching pm_runtime_disable()? Should be one in
> .remove(), or use devm_add_action_or_reset() to wrap a call to it.

Ah, right, i need to handle that.

> 
> Also: do you really need to test for dev->pm_domain in your patch?
> Seems like it should always be fine to call pm_runtime_enable() and
> then always fine to call the get/put. ...and presumably always fine to
> even set the performance state?

Sure, i'll give it a try and see if that works or ends up throwing me
any warns, i'll repost with that or update if that does not work for
some reason. thanks for the review.

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