Re: [PATCH] PM / devfreq: tegra30: disable clock on error in probe

Dan Carpenter
2020-09-14T14:19:56Z

On Mon, Sep 14, 2020 at 04:56:26PM +0300, Dmitry Osipenko wrote:
> 14.09.2020 10:09, Chanwoo Choi пишет:
> > Hi,
> >
> > On 9/8/20 4:25 PM, Dan Carpenter wrote:
> >> This error path needs to call clk_disable_unprepare().
> >>
> >> Fixes: 7296443b900e ("PM / devfreq: tegra30: Handle possible round-rate error")
> >> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> >> ---
> >> ---
> >> drivers/devfreq/tegra30-devfreq.c | 4 +++-
> >> 1 file changed, 3 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> >> index e94a27804c20..dedd39de7367 100644
> >> --- a/drivers/devfreq/tegra30-devfreq.c
> >> +++ b/drivers/devfreq/tegra30-devfreq.c
> >> @@ -836,7 +836,8 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
> >> 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;
> >> + err = rate;
> >> + goto disable_clk;
> >> }
> >>
> >> tegra->max_freq = rate / KHZ;
> >> @@ -897,6 +898,7 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
> >> dev_pm_opp_remove_all_dynamic(&pdev->dev);
> >>
> >> reset_control_reset(tegra->reset);
> >> +disable_clk:
> >> clk_disable_unprepare(tegra->clock);
> >
> > Is it doesn't need to reset with reset_contrl_reset()?
>
> Hello, Chanwoo!
>
> It's reset just before the clk_round_rate() invocation, hence there
> shouldn't be a need to reset it second time.

Ah... I was looking the wrong code. Plus I don't really know this code
very well.

If clk_prepare_enable() fails, then I would have assumed we need to call
reset_control_deassert(). I would have assumed the
reset_control_assert() and _deassert() functions were paired. So what
I'm suggesting is something like the following: (I'll resend this if
it's correct).

[PATCH] PM / devfreq: tegra30: Add missing reset_control_deassert()

If clk_prepare_enable() fails then probe needs to call the
reset_control_deassert() function.

Fixes: 6234f38016ad ("PM / devfreq: tegra: add devfreq driver for Tegra Activity Monitor")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/devfreq/tegra30-devfreq.c | 1 +
1 file changed, 1 insertions(+), 0 deletion(-)

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index e94a27804c20..ce217aba7b9d 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -828,6 +828,7 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
if (err) {
dev_err(&pdev->dev,
"Failed to prepare and enable ACTMON clock\n");
+ reset_control_deassert(tegra->reset);
return err;
}