From 87041a58d3b19455d39baed2a5e5bb43b58fb915 Mon Sep 17 00:00:00 2001 From: Colin Pitrat Date: Sat, 18 Jun 2016 19:05:04 +0100 Subject: gpio: sch: Fix Oops on module load on Asus Eee PC 1201 This fixes the issue descirbe in bug 117531 (https://bugzilla.kernel.org/show_bug.cgi?id=117531). It's a regression introduced in linux 4.5 that causes a Oops at load of gpio_sch and prevents powering off the computer. The issue is that sch_gpio_reg_set is called in sch_gpio_probe before gpio_chip data is initialized with the pointer to the sch_gpio struct. As sch_gpio_reg_set calls gpiochip_get_data, it returns NULL which causes the Oops. The patch follows Mika's advice (https://lkml.org/lkml/2016/5/9/61) and consists in modifying sch_gpio_reg_get and sch_gpio_reg_set to take a sch_gpio struct directly instead of a gpio_chip, which avoids the call to gpiochip_get_data. Thanks Mika for your patience with me :-) Cc: stable@vger.kernel.org Signed-off-by: Colin Pitrat Acked-by: Alexandre Courbot Acked-by: Mika Westerberg Signed-off-by: Linus Walleij --- drivers/gpio/gpio-sch.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/drivers/gpio/gpio-sch.c b/drivers/gpio/gpio-sch.c index e85e7539cf5d..eb43ae4835c1 100644 --- a/drivers/gpio/gpio-sch.c +++ b/drivers/gpio/gpio-sch.c @@ -61,9 +61,8 @@ static unsigned sch_gpio_bit(struct sch_gpio *sch, unsigned gpio) return gpio % 8; } -static int sch_gpio_reg_get(struct gpio_chip *gc, unsigned gpio, unsigned reg) +static int sch_gpio_reg_get(struct sch_gpio *sch, unsigned gpio, unsigned reg) { - struct sch_gpio *sch = gpiochip_get_data(gc); unsigned short offset, bit; u8 reg_val; @@ -75,10 +74,9 @@ static int sch_gpio_reg_get(struct gpio_chip *gc, unsigned gpio, unsigned reg) return reg_val; } -static void sch_gpio_reg_set(struct gpio_chip *gc, unsigned gpio, unsigned reg, +static void sch_gpio_reg_set(struct sch_gpio *sch, unsigned gpio, unsigned reg, int val) { - struct sch_gpio *sch = gpiochip_get_data(gc); unsigned short offset, bit; u8 reg_val; @@ -98,14 +96,15 @@ static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num) struct sch_gpio *sch = gpiochip_get_data(gc); spin_lock(&sch->lock); - sch_gpio_reg_set(gc, gpio_num, GIO, 1); + sch_gpio_reg_set(sch, gpio_num, GIO, 1); spin_unlock(&sch->lock); return 0; } static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num) { - return sch_gpio_reg_get(gc, gpio_num, GLV); + struct sch_gpio *sch = gpiochip_get_data(gc); + return sch_gpio_reg_get(sch, gpio_num, GLV); } static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val) @@ -113,7 +112,7 @@ static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val) struct sch_gpio *sch = gpiochip_get_data(gc); spin_lock(&sch->lock); - sch_gpio_reg_set(gc, gpio_num, GLV, val); + sch_gpio_reg_set(sch, gpio_num, GLV, val); spin_unlock(&sch->lock); } @@ -123,7 +122,7 @@ static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num, struct sch_gpio *sch = gpiochip_get_data(gc); spin_lock(&sch->lock); - sch_gpio_reg_set(gc, gpio_num, GIO, 0); + sch_gpio_reg_set(sch, gpio_num, GIO, 0); spin_unlock(&sch->lock); /* @@ -182,13 +181,13 @@ static int sch_gpio_probe(struct platform_device *pdev) * GPIO7 is configured by the CMC as SLPIOVR * Enable GPIO[9:8] core powered gpios explicitly */ - sch_gpio_reg_set(&sch->chip, 8, GEN, 1); - sch_gpio_reg_set(&sch->chip, 9, GEN, 1); + sch_gpio_reg_set(sch, 8, GEN, 1); + sch_gpio_reg_set(sch, 9, GEN, 1); /* * SUS_GPIO[2:0] enabled by default * Enable SUS_GPIO3 resume powered gpio explicitly */ - sch_gpio_reg_set(&sch->chip, 13, GEN, 1); + sch_gpio_reg_set(sch, 13, GEN, 1); break; case PCI_DEVICE_ID_INTEL_ITC_LPC: -- cgit v1.2.3 From 85b03b3033fd4eba82665b3b9902c095a08cc52f Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sun, 3 Jul 2016 18:32:05 +0200 Subject: Revert "gpiolib: Split GPIO flags parsing and GPIO configuration" This reverts commit 923b93e451db876d1479d3e4458fce14fec31d1c. Make sure consumers do not overwrite gpio flags for pins that have already been claimed. While adding support for gpio drivers to refuse a request using unsupported flags, the order of when the requested flag was checked and the new flags were applied was reversed to that consumers could overwrite flags for already requested gpios. This not only affects device-tree setups where two drivers could request the same gpio using conflicting configurations, but also allowed user space to clear gpio flags for already claimed pins simply by attempting to export them through the sysfs interface. By for example clearing the FLAG_ACTIVE_LOW flag this way, user space could effectively change the polarity of a signal. Reverting this change obviously prevents gpio drivers from doing sanity checks on the flags in their request callbacks. Fortunately only one recently added driver (gpio-tps65218 in v4.6) appears to do this, and a follow up patch could restore this functionality through a different interface. Cc: stable # 4.4 Signed-off-by: Johan Hovold Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-legacy.c | 8 +++---- drivers/gpio/gpiolib.c | 52 +++++++++++++------------------------------ 2 files changed, 20 insertions(+), 40 deletions(-) diff --git a/drivers/gpio/gpiolib-legacy.c b/drivers/gpio/gpiolib-legacy.c index 3a5c7011ad3b..8b830996fe02 100644 --- a/drivers/gpio/gpiolib-legacy.c +++ b/drivers/gpio/gpiolib-legacy.c @@ -28,6 +28,10 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) if (!desc && gpio_is_valid(gpio)) return -EPROBE_DEFER; + err = gpiod_request(desc, label); + if (err) + return err; + if (flags & GPIOF_OPEN_DRAIN) set_bit(FLAG_OPEN_DRAIN, &desc->flags); @@ -37,10 +41,6 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) if (flags & GPIOF_ACTIVE_LOW) set_bit(FLAG_ACTIVE_LOW, &desc->flags); - err = gpiod_request(desc, label); - if (err) - return err; - if (flags & GPIOF_DIR_IN) err = gpiod_direction_input(desc); else diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 570771ed19e6..be74bd370f1f 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1352,14 +1352,6 @@ static int __gpiod_request(struct gpio_desc *desc, const char *label) spin_lock_irqsave(&gpio_lock, flags); } done: - if (status < 0) { - /* Clear flags that might have been set by the caller before - * requesting the GPIO. - */ - clear_bit(FLAG_ACTIVE_LOW, &desc->flags); - clear_bit(FLAG_OPEN_DRAIN, &desc->flags); - clear_bit(FLAG_OPEN_SOURCE, &desc->flags); - } spin_unlock_irqrestore(&gpio_lock, flags); return status; } @@ -2587,28 +2579,13 @@ struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, } EXPORT_SYMBOL_GPL(gpiod_get_optional); -/** - * gpiod_parse_flags - helper function to parse GPIO lookup flags - * @desc: gpio to be setup - * @lflags: gpio_lookup_flags - returned from of_find_gpio() or - * of_get_gpio_hog() - * - * Set the GPIO descriptor flags based on the given GPIO lookup flags. - */ -static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags) -{ - if (lflags & GPIO_ACTIVE_LOW) - set_bit(FLAG_ACTIVE_LOW, &desc->flags); - if (lflags & GPIO_OPEN_DRAIN) - set_bit(FLAG_OPEN_DRAIN, &desc->flags); - if (lflags & GPIO_OPEN_SOURCE) - set_bit(FLAG_OPEN_SOURCE, &desc->flags); -} /** * gpiod_configure_flags - helper function to configure a given GPIO * @desc: gpio whose value will be assigned * @con_id: function within the GPIO consumer + * @lflags: gpio_lookup_flags - returned from of_find_gpio() or + * of_get_gpio_hog() * @dflags: gpiod_flags - optional GPIO initialization flags * * Return 0 on success, -ENOENT if no GPIO has been assigned to the @@ -2616,10 +2593,17 @@ static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags) * occurred while trying to acquire the GPIO. */ static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, - enum gpiod_flags dflags) + unsigned long lflags, enum gpiod_flags dflags) { int status; + if (lflags & GPIO_ACTIVE_LOW) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + if (lflags & GPIO_OPEN_DRAIN) + set_bit(FLAG_OPEN_DRAIN, &desc->flags); + if (lflags & GPIO_OPEN_SOURCE) + set_bit(FLAG_OPEN_SOURCE, &desc->flags); + /* No particular flag request, return here... */ if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) { pr_debug("no flags found for %s\n", con_id); @@ -2686,13 +2670,11 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, return desc; } - gpiod_parse_flags(desc, lookupflags); - status = gpiod_request(desc, con_id); if (status < 0) return ERR_PTR(status); - status = gpiod_configure_flags(desc, con_id, flags); + status = gpiod_configure_flags(desc, con_id, lookupflags, flags); if (status < 0) { dev_dbg(dev, "setup of GPIO %s failed\n", con_id); gpiod_put(desc); @@ -2748,6 +2730,10 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, if (IS_ERR(desc)) return desc; + ret = gpiod_request(desc, NULL); + if (ret) + return ERR_PTR(ret); + if (active_low) set_bit(FLAG_ACTIVE_LOW, &desc->flags); @@ -2758,10 +2744,6 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, set_bit(FLAG_OPEN_SOURCE, &desc->flags); } - ret = gpiod_request(desc, NULL); - if (ret) - return ERR_PTR(ret); - return desc; } EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod); @@ -2814,8 +2796,6 @@ int gpiod_hog(struct gpio_desc *desc, const char *name, chip = gpiod_to_chip(desc); hwnum = gpio_chip_hwgpio(desc); - gpiod_parse_flags(desc, lflags); - local_desc = gpiochip_request_own_desc(chip, hwnum, name); if (IS_ERR(local_desc)) { status = PTR_ERR(local_desc); @@ -2824,7 +2804,7 @@ int gpiod_hog(struct gpio_desc *desc, const char *name, return status; } - status = gpiod_configure_flags(desc, name, dflags); + status = gpiod_configure_flags(desc, name, lflags, dflags); if (status < 0) { pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n", name, chip->label, hwnum, status); -- cgit v1.2.3 From 92c74bceb0dd4b74a6c0b56c2f9a5c93a0860808 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 5 Jul 2016 08:46:43 +0200 Subject: Revert "gpio: gpiolib-of: Allow compile testing" This reverts commit 1e4a80640338924b9f9fd7a121ac31d08134410a. This creates more problems than it solves right now. Compile testing needs to go in with patches fixing the problems it uncovers. Signed-off-by: Linus Walleij --- drivers/gpio/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index cebcb405812e..536112fd2466 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -49,7 +49,7 @@ config GPIO_DEVRES config OF_GPIO def_bool y - depends on OF || COMPILE_TEST + depends on OF config GPIO_ACPI def_bool y -- cgit v1.2.3