Messages in this thread | | | Date | Mon, 2 May 2022 21:37:16 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH v2 2/2] watchdog: max63xx_wdt: Add support for specifying WDI logic via GPIO |
| |
On 5/2/22 20:57, Tzung-Bi Shih wrote: > On Fri, Apr 29, 2022 at 03:13:49PM +0200, Pali Rohár wrote: >> @@ -27,6 +27,7 @@ >> #include <linux/io.h> >> #include <linux/slab.h> >> #include <linux/property.h> >> +#include <linux/gpio/consumer.h> > > It would be better to keep them alphabetically. Anyway, they aren't sorted > originally... > >> +static void max63xx_gpio_ping(struct max63xx_wdt *wdt) >> +{ >> + spin_lock(&wdt->lock); > > Does it really need to acquire the lock? It looks like the lock is to prevent > concurrent accesses to the mmap in max63xx_mmap_ping() and max63xx_mmap_set(). >
Actually, that doesn't work at all. spin_lock() directly contradicts with gpiod_set_value_cansleep().
>> + gpiod_set_value_cansleep(wdt->gpio_wdi, 1); >> + udelay(1); > > Doesn't it need to include <linux/delay.h> for udelay()? > >> @@ -225,10 +240,19 @@ static int max63xx_wdt_probe(struct platform_device *pdev) >> return -EINVAL; >> } >> >> + wdt->gpio_wdi = devm_gpiod_get(dev, NULL, GPIOD_FLAGS_BIT_DIR_OUT); >> + if (IS_ERR(wdt->gpio_wdi) && PTR_ERR(wdt->gpio_wdi) != -ENOENT) > > Use devm_gpiod_get_optional() to make the intent clear. Also, it gets rid of > the check for -ENOENT. > >> + return dev_err_probe(dev, PTR_ERR(wdt->gpio_wdi), >> + "unable to request gpio: %ld\n", >> + PTR_ERR(wdt->gpio_wdi)); > > It doesn't need to again print for PTR_ERR(wdt->gpio_wdi). dev_err_probe() > prints the error. > >> err = max63xx_mmap_init(pdev, wdt); >> if (err) >> return err; >> >> + if (!IS_ERR(wdt->gpio_wdi)) >> + wdt->ping = max63xx_gpio_ping; > > Thus, the max63xx_gpio_ping() overrides max63xx_mmap_ping() if the GPIO was > provided? It would be better to mention the behavior in the commit message. > > Also, could both the assignments of `wdt->gpio_wdi` and `wdt->ping` happen > after max63xx_mmap_init()?
| |