Re: [PATCH v2 3/4] cpufreq: s5pv210: Defer probe if getting regulators fail

From: Krzysztof Kozlowski
Date: Fri Jan 11 2019 - 04:46:43 EST


On Thu, 10 Jan 2019 at 21:53, PaweÅ Chmiel
<pawel.mikolaj.chmiel@xxxxxxxxx> wrote:
>
> There is possibility, that when probing driver, regulators are not yet
> initialized. In this case we should return EPROBE_DEFER and wait till
> they're initialized, since they're required currently for cpufreq driver
> to work. Also move regulator initialization code at beginning of probe,
> so we can defer as fast as posibble.
>
> Signed-off-by: PaweÅ Chmiel <pawel.mikolaj.chmiel@xxxxxxxxx>
> ---
> Changes from v1:
> - Fix compilation error
> - Reorganize code so it's smaller
> ---
> drivers/cpufreq/s5pv210-cpufreq.c | 32 ++++++++++++++++++-------------
> 1 file changed, 19 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
> index f51697f1e0b3..6df95941ba96 100644
> --- a/drivers/cpufreq/s5pv210-cpufreq.c
> +++ b/drivers/cpufreq/s5pv210-cpufreq.c
> @@ -594,6 +594,25 @@ static int s5pv210_cpufreq_probe(struct platform_device *pdev)
> * this whole driver as soon as S5PV210 gets migrated to use
> * cpufreq-dt driver.
> */
> + arm_regulator = regulator_get(NULL, "vddarm");
> + if (IS_ERR(arm_regulator)) {
> + if (PTR_ERR(arm_regulator) == -EPROBE_DEFER)
> + pr_debug("vddarm regulator not ready, defer\n");
> + else
> + pr_err("failed to get regulator vddarm\n");
> + return PTR_ERR(arm_regulator);
> + }
> +
> + int_regulator = regulator_get(NULL, "vddint");
> + if (IS_ERR(int_regulator)) {
> + if (PTR_ERR(int_regulator) == -EPROBE_DEFER)
> + pr_debug("vddint regulator not ready, defer\n");
> + else
> + pr_err("failed to get regulator vddint\n");
> + regulator_put(arm_regulator);
> + return PTR_ERR(int_regulator);
> + }
> +

Error paths are now not correct. You should put the regulators when
returning later. The previous code had these error paths wrong as well
- not iounmapping - but if you move things around, maybe let's fix
things.

Best regards,
Krzysztof