Re: [PATCH v1] PM / devfreq: tegra30: Improve initial hardware resetting

From: Chanwoo Choi
Date: Sun Sep 27 2020 - 23:08:02 EST


On 9/28/20 5:51 AM, Dmitry Osipenko wrote:
> It's safe to enable the ACTMON clock at any time during driver probing,
> even if we don't know the state of hardware, because it's used only for
> collecting and processing stats, and interrupt is kept disabled. This
> allows us to slightly improve code which performs initial hardware
> resetting by making use of a single reset_control_reset() instead of
> assert/deassert pair. Secondly, a potential error of the reset-control
> API is handled nicely now.
>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/devfreq/tegra30-devfreq.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index dedd39de7367..f5e74c2ede85 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -822,8 +822,6 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
> return err;
> }
>
> - reset_control_assert(tegra->reset);
> -
> err = clk_prepare_enable(tegra->clock);
> if (err) {
> dev_err(&pdev->dev,
> @@ -831,7 +829,11 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
> return err;
> }
>
> - reset_control_deassert(tegra->reset);
> + err = reset_control_reset(tegra->reset);
> + if (err) {
> + dev_err(&pdev->dev, "Failed to reset hardware: %d\n", err);
> + goto disable_clk;
> + }
>
> rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
> if (rate < 0) {
>

Applied it. Thanks.

--
Best Regards,
Chanwoo Choi
Samsung Electronics