From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux admin Subject: Re: [PATCH v6] gpio/mpc8xxx: change irq handler from chained to normal Date: Wed, 9 Oct 2019 17:36:29 +0100 Message-ID: <20191009163628.GH25745@shell.armlinux.org.uk> References: <20191009083021.33529-1-hui.song_1@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20191009083021.33529-1-hui.song_1@nxp.com> Sender: linux-kernel-owner@vger.kernel.org To: Hui Song Cc: Shawn Guo , Li Yang , Rob Herring , Mark Rutland , Linus Walleij , Bartosz Golaszewski , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org List-Id: devicetree@vger.kernel.org On Wed, Oct 09, 2019 at 04:30:21PM +0800, Hui Song wrote: > From: Song Hui > > More than one gpio controllers can share one interrupt, change the > driver to request shared irq. > > While this will work, it will mess up userspace accounting of the number > of interrupts per second in tools such as vmstat. The reason is that > for every GPIO interrupt, /proc/interrupts records the count against GIC > interrupt 68 or 69, as well as the GPIO itself. So, for every GPIO > interrupt, the total number of interrupts that the system has seen > increments by two > > Signed-off-by: Laurentiu Tudor > Signed-off-by: Alex Marginean > Signed-off-by: Song Hui > --- > Changes in v6: > - change request_irq to devm_request_irq and add commit message. > Changes in v5: > - add traverse every bit function. > Changes in v4: > - convert 'pr_err' to 'dev_err'. > Changes in v3: > - update the patch description. > Changes in v2: > - delete the compatible of ls1088a. > > drivers/gpio/gpio-mpc8xxx.c | 31 ++++++++++++++++++++----------- > 1 file changed, 20 insertions(+), 11 deletions(-) > > diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c > index 16a47de..f0be284 100644 > --- a/drivers/gpio/gpio-mpc8xxx.c > +++ b/drivers/gpio/gpio-mpc8xxx.c > @@ -22,6 +22,7 @@ > #include > #include > #include > +#include > > #define MPC8XXX_GPIO_PINS 32 > > @@ -127,20 +128,20 @@ static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset) > return -ENXIO; > } > > -static void mpc8xxx_gpio_irq_cascade(struct irq_desc *desc) > +static irqreturn_t mpc8xxx_gpio_irq_cascade(int irq, void *data) > { > - struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_desc_get_handler_data(desc); > - struct irq_chip *chip = irq_desc_get_chip(desc); > + struct mpc8xxx_gpio_chip *mpc8xxx_gc = data; > struct gpio_chip *gc = &mpc8xxx_gc->gc; > unsigned int mask; This needs to be "unsigned long mask;" for for_each_set_bit() not to complain. > + int i; > > mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_IER) > & gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR); > - if (mask) > + for_each_set_bit(i, &mask, 32) > generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq, > - 32 - ffs(mask))); > - if (chip->irq_eoi) > - chip->irq_eoi(&desc->irq_data); > + 31 - i)); > + > + return IRQ_HANDLED; > } > > static void mpc8xxx_irq_unmask(struct irq_data *d) > @@ -388,8 +389,8 @@ static int mpc8xxx_probe(struct platform_device *pdev) > > ret = gpiochip_add_data(gc, mpc8xxx_gc); > if (ret) { > - pr_err("%pOF: GPIO chip registration failed with status %d\n", > - np, ret); > + dev_err(&pdev->dev, "%pOF: GPIO chip registration failed with status %d\n", > + np, ret); > goto err; > } > > @@ -409,8 +410,16 @@ static int mpc8xxx_probe(struct platform_device *pdev) > if (devtype->gpio_dir_in_init) > devtype->gpio_dir_in_init(gc); > > - irq_set_chained_handler_and_data(mpc8xxx_gc->irqn, > - mpc8xxx_gpio_irq_cascade, mpc8xxx_gc); > + ret = devm_request_irq(&pdev->dev, mpc8xxx_gc->irqn, > + mpc8xxx_gpio_irq_cascade, > + IRQF_NO_THREAD | IRQF_SHARED, "gpio-cascade", > + mpc8xxx_gc); > + if (ret) { > + dev_err(&pdev->dev, "%s: failed to devm_request_irq(%d), ret = %d\n", > + np->full_name, mpc8xxx_gc->irqn, ret); > + goto err; > + } > + > return 0; > err: > iounmap(mpc8xxx_gc->regs); > -- > 2.9.5 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up