Re: [PATCH v1 1/2] driver core: add a wrapper to device probe log helper to return pointer

From: Geert Uytterhoeven
Date: Mon Feb 14 2022 - 09:55:51 EST


Hi Andy,

On Mon, Feb 14, 2022 at 3:32 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> Sometimes the ->probe() function can be split to the core and actual probe
> parts. In such cases the core one may return a pointer to the allocated
> resource, or error pointer in unsuccessful scenario. Allow that kind of
> core function to use dev_err_probe_ptr(), so the following excerpt
>
> ret = bar(...);
> if (ret) {
> dev_err_probe(dev, ret, ...);
> return ERR_PTR(ret);
> }
>
> can be replaced with
>
> ret = bar(...);
> if (ret)
> return dev_err_probe_ptr(dev, ret, ...);
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

Thanks for your patch!

> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -14,6 +14,7 @@
>
> #include <linux/dev_printk.h>
> #include <linux/energy_model.h>
> +#include <linux/err.h>
> #include <linux/ioport.h>
> #include <linux/kobject.h>
> #include <linux/klist.h>
> @@ -982,6 +983,13 @@ void device_links_supplier_sync_state_resume(void);
> extern __printf(3, 4)
> int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
>
> +/* As above, but returns error pointer */
> +static inline __printf(3, 0)
> +void *dev_err_probe_ptr(const struct device *dev, int err, const char *fmt, va_list args)

Shouldn't this be a varargs function, like dev_err_probe()?

> +{
> + return ERR_PTR(dev_err_probe(dev, err, fmt, args));
> +}
> +
> /* Create alias, so I can be autoloaded. */
> #define MODULE_ALIAS_CHARDEV(major,minor) \
> MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds