Re: [PATCH] thermal: sun8i: Be loud when probe fails

[Frank Lee]

HI Ondrej,
On Wed, Jul 8, 2020 at 6:55 PM Ondrej Jirman <megous@xxxxxxxxxx> wrote:
>
> I noticed several mobile Linux distributions failing to enable the
> thermal regulation correctly, because the kernel is silent
> when thermal driver fails to probe. Add enough error reporting
> to debug issues and warn users in case thermal sensor is failing
> to probe.
>
> Failing to notify users means, that SoC can easily overheat under
> load.
>
> Signed-off-by: Ondrej Jirman <megous@xxxxxxxxxx>
> ---
>  drivers/thermal/sun8i_thermal.c | 55 ++++++++++++++++++++++++++-------
>  1 file changed, 43 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_thermal.c
> index 74d73be16496..9065e79ae743 100644
> --- a/drivers/thermal/sun8i_thermal.c
> +++ b/drivers/thermal/sun8i_thermal.c
> @@ -287,8 +287,12 @@ static int sun8i_ths_calibrate(struct ths_device *tmdev)
>
>         calcell = devm_nvmem_cell_get(dev, "calibration");
>         if (IS_ERR(calcell)) {
> +               dev_err(dev, "Failed to get calibration nvmem cell (%ld)\n",
> +                       PTR_ERR(calcell));
> +
>                 if (PTR_ERR(calcell) == -EPROBE_DEFER)
>                         return -EPROBE_DEFER;
> +
>                 /*
>                  * Even if the external calibration data stored in sid is
>                  * not accessible, the THS hardware can still work, although
> @@ -308,6 +312,8 @@ static int sun8i_ths_calibrate(struct ths_device *tmdev)
>         caldata = nvmem_cell_read(calcell, &callen);
>         if (IS_ERR(caldata)) {
>                 ret = PTR_ERR(caldata);
> +               dev_err(dev, "Failed to read calibration data (%d)\n",
> +                       ret);
>                 goto out;
>         }
>
> @@ -330,23 +336,35 @@ static int sun8i_ths_resource_init(struct ths_device *tmdev)
>                 return PTR_ERR(base);
>
>         tmdev->regmap = devm_regmap_init_mmio(dev, base, &config);
> -       if (IS_ERR(tmdev->regmap))
> +       if (IS_ERR(tmdev->regmap)) {
> +               dev_err(dev, "Failed to init regmap (%ld)\n",
> +                       PTR_ERR(tmdev->regmap));
>                 return PTR_ERR(tmdev->regmap);
> +       }
>
>         if (tmdev->chip->has_bus_clk_reset) {
>                 tmdev->reset = devm_reset_control_get(dev, NULL);
> -               if (IS_ERR(tmdev->reset))
> +               if (IS_ERR(tmdev->reset)) {
> +                       dev_err(dev, "Failed to get reset (%ld)\n",
> +                               PTR_ERR(tmdev->reset));
>                         return PTR_ERR(tmdev->reset);
> +               }
>
>                 tmdev->bus_clk = devm_clk_get(&pdev->dev, "bus");
> -               if (IS_ERR(tmdev->bus_clk))
> +               if (IS_ERR(tmdev->bus_clk)) {
> +                       dev_err(dev, "Failed to get bus clock (%ld)\n",
> +                               PTR_ERR(tmdev->bus_clk));
>                         return PTR_ERR(tmdev->bus_clk);
> +               }
>         }
>
>         if (tmdev->chip->has_mod_clk) {
>                 tmdev->mod_clk = devm_clk_get(&pdev->dev, "mod");
> -               if (IS_ERR(tmdev->mod_clk))
> +               if (IS_ERR(tmdev->mod_clk)) {
> +                       dev_err(dev, "Failed to get mod clock (%ld)\n",
> +                               PTR_ERR(tmdev->mod_clk));
>                         return PTR_ERR(tmdev->mod_clk);
> +               }
>         }
>
>         ret = reset_control_deassert(tmdev->reset);
> @@ -471,8 +489,12 @@ static int sun8i_ths_register(struct ths_device *tmdev)
>                                                              i,
>                                                              &tmdev->sensor[i],
>                                                              &ths_ops);
> -               if (IS_ERR(tmdev->sensor[i].tzd))
> +               if (IS_ERR(tmdev->sensor[i].tzd)) {
> +                       dev_err(tmdev->dev,
> +                               "Failed to register sensor %d (%ld)\n",
> +                               i, PTR_ERR(tmdev->sensor[i].tzd));
>                         return PTR_ERR(tmdev->sensor[i].tzd);
> +               }
>
>                 if (devm_thermal_add_hwmon_sysfs(tmdev->sensor[i].tzd))
>                         dev_warn(tmdev->dev,
> @@ -501,19 +523,21 @@ static int sun8i_ths_probe(struct platform_device *pdev)
>
>         ret = sun8i_ths_resource_init(tmdev);
>         if (ret)
> -               return ret;
> +               goto err_out;
>
>         irq = platform_get_irq(pdev, 0);
> -       if (irq < 0)
> -               return irq;
> +       if (irq < 0) {
> +               ret = irq;
> +               goto err_out;
> +       }
>
>         ret = tmdev->chip->init(tmdev);
>         if (ret)
> -               return ret;
> +               goto err_out;
>
>         ret = sun8i_ths_register(tmdev);
>         if (ret)
> -               return ret;
> +               goto err_out;
>
>         /*
>          * Avoid entering the interrupt handler, the thermal device is not
> @@ -523,10 +547,17 @@ static int sun8i_ths_probe(struct platform_device *pdev)
>         ret = devm_request_threaded_irq(dev, irq, NULL,
>                                         sun8i_irq_thread,
>                                         IRQF_ONESHOT, "ths", tmdev);
> -       if (ret)
> -               return ret;
> +       if (ret) {
> +               dev_err(dev, "Failed to request irq (%d)\n", ret);
> +               goto err_out;
> +       }
>
> +       dev_info(dev, "Thermal sensor ready!\n");
>         return 0;
> +
> +err_out:
> +       dev_err(dev, "Failed to probe thermal sensor (%d)\n", ret);

When the driver fails, there will be this print. Isn't it superfluous
for you to add theseï

sun8i-thermal: probe of 5070400.thermal-sensor failed with error


Yangtao