Re: [PATCH 6/8] watchdog: st_wdt: Add new driver for ST's LPC Watchdog

Lee Jones
2014-12-18T08:26:52Z

On Wed, 17 Dec 2014, Guenter Roeck wrote:
> On Wed, Dec 17, 2014 at 04:45:25PM +0000, Lee Jones wrote:
> > Signed-off-by: David Paris <david.paris@st.com>
> > Signed-off-by: Lee Jones <lee.jones@linaro.org>
>
> Hi Lee and David,
>
> I still have a couple of comments below. Sorry I didn't catch those earlier.
>
> Thanks,
> Guenter
>
> > ---
> > drivers/watchdog/Kconfig | 13 ++
> > drivers/watchdog/Makefile | 1 +
> > drivers/watchdog/st_wdt.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 337 insertions(+)
> > create mode 100644 drivers/watchdog/st_wdt.c

Chopping all the crud.

[...]

> > +static struct of_device_id st_wdog_match[] = {
> > + {
> > + .compatible = "st,stih407-lpc",
> > + .data = (void *)&stih407_syscfg,
>
> Nitpick: typecast to and from void * is not necessary.

Actually that's not true, but it is superfluous in this case.

I will fix-up.

[...]

> > +static int st_wdog_probe(struct platform_device *pdev)
> > +{
> > + const struct of_device_id *match;
> > + struct device_node *np = pdev->dev.of_node;
> > + struct st_wdog *st_wdog;
> > + struct regmap *regmap;
> > + struct resource *res;
> > + struct clk *clk;
> > + void __iomem *base;
> > + uint32_t mode;
> > + int ret;

[...]

> > + clk = clk_get(&pdev->dev, NULL);
> > + if (IS_ERR(clk)) {
> > + dev_err(&pdev->dev, "Unable to request clock\n");
> > + return PTR_ERR(clk);
> > + }
> > + clk_prepare_enable(st_wdog->clk);
>
> How does this work ? st_wdog->clk isn't set yet.

Great spot. That should be 'clk'.

It works because the LPC clk is already on.

> > +
> > + st_wdog->dev = &pdev->dev;
> > + st_wdog->base = base;
> > + st_wdog->clk = clk;
> > + st_wdog->syscfg->regmap = regmap;
> > + st_wdog->warm_reset = of_property_read_bool(np, "st,warm_reset");
> > + st_wdog->clkrate = clk_get_rate(st_wdog->clk);
> > +
> > + if (!st_wdog->clkrate) {
> > + dev_err(&pdev->dev, "Unable to fetch clock rate\n");
>
> I think this is missing
> clk_disable_unprepare();
> clk_put();
>
> Same for the rest of the error path handling below.

Actually instead of clk_put we should be using s/clk_get/devm_clk_get/.

You're right about the error paths. I will enforce a better one.

Thanks.

[...]

> > +#ifdef CONFIG_PM
>
> I think this needs to be CONFIG_PM_SLEEP.
> Another option might be to drop the #ifdef entirely and use
> __maybe_unused instead.

Hmmm... what version is this?

[2 mins pass]

Oh rubbish. I've been a silly boy!

[spoiler alert: take a look at the end of the RTC driver patch]

Will be fixed in v3.

[...]

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
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