Re: [PATCH for-3.18.y+] pinctrl: msm: fix gpio-hog related boot issues

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Feb 18, 2019 at 06:00:11PM +0530, Amit Pundir wrote:
> From: Christian Lamparter <chunkeey@gmail.com>
> 
> commit a86caa9ba5d70696ceb35d1d39caa20d8b641387 upstream.
> 
> Sven Eckelmann reported an issue with the current IPQ4019 pinctrl.
> Setting up any gpio-hog in the device-tree for his device would
> "kill the bootup completely":
> 
> | [    0.477838] msm_serial 78af000.serial: could not find pctldev for node /soc/pinctrl@1000000/serial_pinmux, deferring probe
> | [    0.499828] spi_qup 78b5000.spi: could not find pctldev for node /soc/pinctrl@1000000/spi_0_pinmux, deferring probe
> | [    1.298883] requesting hog GPIO enable USB2 power (chip 1000000.pinctrl, offset 58) failed, -517
> | [    1.299609] gpiochip_add_data: GPIOs 0..99 (1000000.pinctrl) failed to register
> | [    1.308589] ipq4019-pinctrl 1000000.pinctrl: Failed register gpiochip
> | [    1.316586] msm_serial 78af000.serial: could not find pctldev for node /soc/pinctrl@1000000/serial_pinmux, deferring probe
> | [    1.322415] spi_qup 78b5000.spi: could not find pctldev for node /soc/pinctrl@1000000/spi_0_pinmux, deferri
> 
> This was also verified on a RT-AC58U (IPQ4018) which would
> no longer boot, if a gpio-hog was specified. (Tried forcing
> the USB LED PIN (GPIO0) to high.).
> 
> The problem is that Pinctrl+GPIO registration is currently
> peformed in the following order in pinctrl-msm.c:
> 	1. pinctrl_register()
> 	2. gpiochip_add()
> 	3. gpiochip_add_pin_range()
> 
> The actual error code -517 == -EPROBE_DEFER is coming from
> pinctrl_get_device_gpio_range(), which is called through:
>         gpiochip_add
>             of_gpiochip_add
>                 of_gpiochip_scan_gpios
>                     gpiod_hog
>                         gpiochip_request_own_desc
>                             __gpiod_request
>                                 chip->request
>                                     gpiochip_generic_request
>                                        pinctrl_gpio_request
>                                           pinctrl_get_device_gpio_range
> 
> pinctrl_get_device_gpio_range() is unable to find any valid
> pin ranges, since nothing has been added to the pinctrldev_list yet.
> so the range can't be found, and the operation fails with -EPROBE_DEFER.
> 
> This patch fixes the issue by adding the "gpio-ranges" property to
> the pinctrl device node of all upstream Qcom SoC. The pin ranges are
> then added by the gpio core.
> 
> In order to remain compatible with older, existing DTs (and ACPI)
> a check for the "gpio-ranges" property has been added to
> msm_gpio_init(). This prevents the driver of adding the same entry
> to the pinctrldev_list twice.
> 
> Reported-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
> Tested-by: Sven Eckelmann <sven.eckelmann@openmesh.com> [ipq4019]
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> [AmitP: Minor rebasing for Stable]
> Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
> ---
> Cherry-picked from lede tree https://git.lede-project.org/?p=source.git
> and build tested for LTS trees up to v4.14.y for ARCH=arm/arm64 defconfig.

Now applied, thanks.

greg k-h