Re: [PATCH v4 03/24] PM / devfreq: tegra30: Handle possible round-rate error

Chanwoo Choi
2019-07-16T11:50:08Z

On 19. 7. 8. 오전 7:32, Dmitry Osipenko wrote:
> The EMC clock rate rounding technically could fail, hence let's handle
> the error cases properly.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/devfreq/tegra30-devfreq.c | 17 +++++++++++++++--
> 1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index 5e2b133babdd..5e606ae3f238 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -592,8 +592,8 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
> struct tegra_devfreq_device *dev;
> struct tegra_devfreq *tegra;
> struct devfreq *devfreq;
> - unsigned long rate;
> unsigned int i;
> + long rate;
> int err;
>
> tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
> @@ -650,8 +650,14 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>
> reset_control_deassert(tegra->reset);
>
> - tegra->max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX) / KHZ;
> + rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
> + if (rate < 0) {
> + dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", rate);
> + return rate;
> + }
> +
> tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;
> + tegra->max_freq = rate / KHZ;
>
> for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
> dev = tegra->devices + i;
> @@ -662,6 +668,13 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
> for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
> rate = clk_round_rate(tegra->emc_clock, rate);
>

Please remove unneeded blank line.

> + if (rate < 0) {
> + dev_err(&pdev->dev,
> + "Failed to round clock rate: %ld\n", rate);
> + err = rate;
> + goto remove_opps;
> + }

Also, this patch doesn't contain code which restore the previous
tegra->cur_freq/max_freq when error happen.

> +
> err = dev_pm_opp_add(&pdev->dev, rate, 0);
> if (err) {
> dev_err(&pdev->dev, "Failed to add OPP: %d\n", err);
>

--
Best Regards,
Chanwoo Choi
Samsung Electronics