| Message ID | 20181111013411.14153-1-masneyb@onstation.org |
|---|---|
| State | New |
| Headers | show |
| Series | pinctrl: qcom: ssbi-gpio: fix gpio-hog related boot issues | expand |
On Sat 10 Nov 17:34 PST 2018, Brian Masney wrote: > When attempting to setup up a gpio hog, device probing will repeatedly > fail with -EPROBE_DEFERED errors. It is caused by a circular dependency > between the gpio and pinctrl frameworks. If the gpio-ranges property is > present in device tree, then the gpio framework will handle the gpio pin > registration and eliminate the circular dependency. > > See Christian Lamparter's commit a86caa9ba5d7 ("pinctrl: msm: fix > gpio-hog related boot issues") for a detailed commit message that > explains the issue in much more detail. The code comment in this commit > came from Christian's commit. > > I did not test this change against any hardware supported by this > particular driver, however I was able to validate this same fix works > for pinctrl-spmi-gpio.c using a LG Nexus 5 (hammerhead) phone. > > Signed-off-by: Brian Masney <masneyb@onstation.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Regards, Bjorn > --- > For the patch and discussion regarding pinctrl-spmi-gpio.c, see > https://lore.kernel.org/lkml/20181101001149.13453-6-masneyb@onstation.org/ > > drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c | 23 +++++++++++++++++------ > 1 file changed, 17 insertions(+), 6 deletions(-) > > diff --git a/drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c b/drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c > index 6b30bef829ab..ded7d765af2e 100644 > --- a/drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c > +++ b/drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c > @@ -762,12 +762,23 @@ static int pm8xxx_gpio_probe(struct platform_device *pdev) > return ret; > } > > - ret = gpiochip_add_pin_range(&pctrl->chip, > - dev_name(pctrl->dev), > - 0, 0, pctrl->chip.ngpio); > - if (ret) { > - dev_err(pctrl->dev, "failed to add pin range\n"); > - goto unregister_gpiochip; > + /* > + * For DeviceTree-supported systems, the gpio core checks the > + * pinctrl's device node for the "gpio-ranges" property. > + * If it is present, it takes care of adding the pin ranges > + * for the driver. In this case the driver can skip ahead. > + * > + * In order to remain compatible with older, existing DeviceTree > + * files which don't set the "gpio-ranges" property or systems that > + * utilize ACPI the driver has to call gpiochip_add_pin_range(). > + */ > + if (!of_property_read_bool(pctrl->dev->of_node, "gpio-ranges")) { > + ret = gpiochip_add_pin_range(&pctrl->chip, dev_name(pctrl->dev), > + 0, 0, pctrl->chip.ngpio); > + if (ret) { > + dev_err(pctrl->dev, "failed to add pin range\n"); > + goto unregister_gpiochip; > + } > } > > platform_set_drvdata(pdev, pctrl); > -- > 2.17.2 >
On Sun, Nov 11, 2018 at 2:34 AM Brian Masney <masneyb@onstation.org> wrote: > When attempting to setup up a gpio hog, device probing will repeatedly > fail with -EPROBE_DEFERED errors. It is caused by a circular dependency > between the gpio and pinctrl frameworks. If the gpio-ranges property is > present in device tree, then the gpio framework will handle the gpio pin > registration and eliminate the circular dependency. > > See Christian Lamparter's commit a86caa9ba5d7 ("pinctrl: msm: fix > gpio-hog related boot issues") for a detailed commit message that > explains the issue in much more detail. The code comment in this commit > came from Christian's commit. > > I did not test this change against any hardware supported by this > particular driver, however I was able to validate this same fix works > for pinctrl-spmi-gpio.c using a LG Nexus 5 (hammerhead) phone. > > Signed-off-by: Brian Masney <masneyb@onstation.org> Patch applied. Yours, Linus Walleij
diff --git a/drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c b/drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c index 6b30bef829ab..ded7d765af2e 100644 --- a/drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c +++ b/drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c @@ -762,12 +762,23 @@ static int pm8xxx_gpio_probe(struct platform_device *pdev) return ret; } - ret = gpiochip_add_pin_range(&pctrl->chip, - dev_name(pctrl->dev), - 0, 0, pctrl->chip.ngpio); - if (ret) { - dev_err(pctrl->dev, "failed to add pin range\n"); - goto unregister_gpiochip; + /* + * For DeviceTree-supported systems, the gpio core checks the + * pinctrl's device node for the "gpio-ranges" property. + * If it is present, it takes care of adding the pin ranges + * for the driver. In this case the driver can skip ahead. + * + * In order to remain compatible with older, existing DeviceTree + * files which don't set the "gpio-ranges" property or systems that + * utilize ACPI the driver has to call gpiochip_add_pin_range(). + */ + if (!of_property_read_bool(pctrl->dev->of_node, "gpio-ranges")) { + ret = gpiochip_add_pin_range(&pctrl->chip, dev_name(pctrl->dev), + 0, 0, pctrl->chip.ngpio); + if (ret) { + dev_err(pctrl->dev, "failed to add pin range\n"); + goto unregister_gpiochip; + } } platform_set_drvdata(pdev, pctrl);
When attempting to setup up a gpio hog, device probing will repeatedly fail with -EPROBE_DEFERED errors. It is caused by a circular dependency between the gpio and pinctrl frameworks. If the gpio-ranges property is present in device tree, then the gpio framework will handle the gpio pin registration and eliminate the circular dependency. See Christian Lamparter's commit a86caa9ba5d7 ("pinctrl: msm: fix gpio-hog related boot issues") for a detailed commit message that explains the issue in much more detail. The code comment in this commit came from Christian's commit. I did not test this change against any hardware supported by this particular driver, however I was able to validate this same fix works for pinctrl-spmi-gpio.c using a LG Nexus 5 (hammerhead) phone. Signed-off-by: Brian Masney <masneyb@onstation.org> --- For the patch and discussion regarding pinctrl-spmi-gpio.c, see https://lore.kernel.org/lkml/20181101001149.13453-6-masneyb@onstation.org/ drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-)