Re: [PATCH v1 04/11] usb: phy: tegra: switch to using devm_gpiod_get()
From: Guenter Roeck <linux@roeck-us.net>
Date: 2022-09-05 22:08:05
Also in:
dri-devel, linux-gpio, linux-pci, linux-tegra, linux-usb, linux-watchdog, lkml
On 9/5/22 12:55, Andy Shevchenko wrote:
On Mon, Sep 5, 2022 at 10:51 PM Dmitry Torokhov [off-list ref] wrote:quoted
On Mon, Sep 05, 2022 at 10:41:40PM +0300, Andy Shevchenko wrote:quoted
On Mon, Sep 5, 2022 at 10:40 PM Dmitry Torokhov [off-list ref] wrote:quoted
On Mon, Sep 05, 2022 at 01:59:44PM +0300, Andy Shevchenko wrote:quoted
On Mon, Sep 5, 2022 at 9:32 AM Dmitry Torokhov [off-list ref] wrote:...quoted
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- gpiod = devm_gpiod_get_from_of_node(&pdev->dev, np, - "nvidia,phy-reset-gpio", - 0, GPIOD_OUT_HIGH, - "ulpi_phy_reset_b"); + 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 ?
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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(). Thanks, Guenter _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel