Re: [PATCH v4 5/5] soc/tegra: pmc: Rate-limit error message about failed to acquire of reset

From: Thierry Reding
Date: Thu Mar 25 2021 - 10:42:38 EST


On Tue, Mar 02, 2021 at 03:25:02PM +0300, Dmitry Osipenko wrote:
> PMC domain could be easily bombarded with the enable requests if there is
> a problem in regards to acquiring reset control of a domain and kernel
> log will be flooded with the error message in this case. Hence rate-limit
> the message in order to prevent missing other important messages.
>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/soc/tegra/pmc.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> index bf29ea22480a..84ab27d85d92 100644
> --- a/drivers/soc/tegra/pmc.c
> +++ b/drivers/soc/tegra/pmc.c
> @@ -868,8 +868,8 @@ static int tegra_genpd_power_off(struct generic_pm_domain *domain)
>
> err = reset_control_acquire(pg->reset);
> if (err < 0) {
> - dev_err(dev, "failed to acquire resets for PM domain %s: %d\n",
> - pg->genpd.name, err);
> + dev_err_ratelimited(dev, "failed to acquire resets for PM domain %s: %d\n",
> + pg->genpd.name, err);

That doesn't look right. This is a serious error condition that
shouldn't happen at all. Ever. If this shows up even once we've got a
serious bug somewhere and we need to fix it rather than "downplay" it
by ratelimiting these errors.

What's the exact use-case where you see this?

Thierry

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