On Mon, Sep 05, 2022 at 03:07:48PM -0700, Guenter Roeck wrote: > On 9/5/22 12:55, Andy Shevchenko wrote: > > On Mon, Sep 5, 2022 at 10:51 PM Dmitry Torokhov > > <dmitry.torokhov@xxxxxxxxx> wrote: > > > On Mon, Sep 05, 2022 at 10:41:40PM +0300, Andy Shevchenko wrote: > > > > On Mon, Sep 5, 2022 at 10:40 PM Dmitry Torokhov > > > > <dmitry.torokhov@xxxxxxxxx> wrote: > > > > > On Mon, Sep 05, 2022 at 01:59:44PM +0300, Andy Shevchenko wrote: > > > > > > On Mon, Sep 5, 2022 at 9:32 AM Dmitry Torokhov > > > > > > <dmitry.torokhov@xxxxxxxxx> wrote: ... > > > > > > > + gpiod = devm_gpiod_get(&pdev->dev, "nvidia,phy-reset", > > > > > > > + GPIOD_OUT_HIGH); > > > > > > > err = PTR_ERR_OR_ZERO(gpiod); > > > > > > > > > > > > What does _OR_ZERO mean now? > > > > > > > > > > This converts a pointer to an error code if a pointer represents > > > > > ERR_PTR() encoded error, or 0 to indicate success. > > > > > > > > Yes, I know that. My point is, how is it useful now (or even before)? > > > > I mean that devm_gpio_get() never returns NULL, right? > > > > > > What does returning NULL have to do with anything. > > > > It has to do with a dead code. If defm_gpiod_get() does not return > > NULL, then why do we even bother to check? > > PTR_ERR_OR_ZERO() converts into an error code (if the pointer is an > ERR_PTR) or 0 if it is a real pointer. Its purpose is not to convert > NULL into 0, its purpose is to convert a pointer either into an error > code or 0. That is what is done here, and it is done all over the place > in the kernel. I don't see your problem with it. Care to explain ? > > > > It converts a pointer > > > to a "classic" return code, with negative errors and 0 on success. > > > > > > It allows to not use multiple IS_ERR/PTR_ERR in the code (I'd need 1 > > > IS_ERR and 2 PTR_ERR, one in dev_err() and another to return). > > > > I don't see how this is relevant. > > You lost me. Really, please explain your problem with PTR_ERR_OR_ZERO(). I don't know what I was thinking about... You, guys, are right, sorry for my noise. -- With Best Regards, Andy Shevchenko
