| Message ID | 20201106192304.49179-4-andriy.shevchenko@linux.intel.com |
|---|---|
| State | Accepted |
| Commit | 8dcb7a15a585b6d0fee15751ce11d7a68cfedd56 |
| Headers | show |
| Series | gpiolib: acpi: pin configuration fixes | expand |
Hi, On 11/9/20 12:45 PM, Andy Shevchenko wrote: > On Sun, Nov 08, 2020 at 10:31:32AM +0100, Hans de Goede wrote: >> On 11/7/20 4:26 PM, Andy Shevchenko wrote: >>> On Sat, Nov 7, 2020 at 4:49 PM Hans de Goede <hdegoede@redhat.com> wrote: >>>> On 11/6/20 8:22 PM, Andy Shevchenko wrote: > > ... > >>> Thank you very much for the testing! I remember that I fixed debounce >>> for BayTrail, but it seems I have yet to fix Cherry Trail pin control >>> as a prerequisite to this patch. >>> >>> And like I said this series is definitely not for backporting. >> >> Independent of fixing the CherryTrail pinctrl driver to support this, >> I strongly believe that -ENOTSUPP should be ignored (treated as success) >> by this patch. Remember ACPI is not only used on x86 but also on ARM >> now a days. We simply cannot guarantee that all pinctrls will support >> (let alone implement) debounce settings. E.g. I'm pretty sure that >> the pinctrl on the popular Allwinner A64 does not support debouncing >> and there are builts using a combination of uboot + EDK2 to boot! >> >> The documentation for gpiod_set_debounce even explicitly mentioned that >> -ENOTSUPP is an error which one may expect (and thus treat specially). >> >> The same goes for the bias stuff too. > > While for debounce I absolutely agree with you I don't think it applies to > bias. ACPI table is coupled with a platform and setting bias == !PullNone > implies that bias is supported. What about PullDefault ? I can easily see DSDT writers using PullDefault on platforms where bias setting is not supported. > If we break something with this it means: > - ACPI table is broken and we need a quirk Broken ACPI tables are as common as rain in the Netherlands, where ever possible we want to deal with these / workaround the brokenness without requiring per device quirks. Requiring a per device quirk for every broken ACPI table out there does not scale. > - GPIO library is broken on architectural level and needs not to return > ENOTSUPP for the flags configuration. Usually we handle features not being implemented gracefully. E.g chances are good that whatever bias is required was already setup by the firmware (or bootloader in the uboot + EDK2 case). Making bias set failures a critical error will likely regress working platforms in various cases. Keep in mind we have an existing userbase where things is working fine without taking the bias settings into account now. So if we hit the -ENOTSUPP case on any platform out there, then that is a regression plain and simple and as you know regressions are a big red flag. Since it is really easy to avoid the regression here we really should avoid it IMHO. What about just printing a warning on ENOTSUPP when setting the bias instead ? Regards, Hans
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index c127b410a7a2..b4a0decfeac2 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -299,6 +299,10 @@ static acpi_status acpi_gpiochip_alloc_event(struct acpi_resource *ares, return AE_OK; } + ret = gpiod_set_debounce(desc, agpio->debounce_timeout); + if (ret) + goto fail_free_desc; + ret = gpiochip_lock_as_irq(chip, pin); if (ret) { dev_err(chip->parent, @@ -664,6 +668,7 @@ static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data) lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr, agpio->pin_table[pin_index]); lookup->info.pin_config = agpio->pin_config; + lookup->info.debounce = agpio->debounce_timeout; lookup->info.gpioint = gpioint; /* @@ -961,6 +966,10 @@ int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index) if (ret < 0) return ret; + ret = gpiod_set_debounce(desc, info.debounce); + if (ret) + return ret; + irq_flags = acpi_dev_get_irq_type(info.triggering, info.polarity); @@ -1048,6 +1057,7 @@ acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address, if (!found) { enum gpiod_flags flags = acpi_gpio_to_gpiod_flags(agpio); const char *label = "ACPI:OpRegion"; + int ret; desc = gpiochip_request_own_desc(chip, pin, label, GPIO_ACTIVE_HIGH, @@ -1058,6 +1068,14 @@ acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address, goto out; } + ret = gpiod_set_debounce(desc, agpio->debounce_timeout); + if (ret) { + status = AE_ERROR; + gpiochip_free_own_desc(desc); + mutex_unlock(&achip->conn_lock); + goto out; + } + conn = kzalloc(sizeof(*conn), GFP_KERNEL); if (!conn) { status = AE_NO_MEMORY; diff --git a/drivers/gpio/gpiolib-acpi.h b/drivers/gpio/gpiolib-acpi.h index 1c6d65cf0629..e2edb632b2cc 100644 --- a/drivers/gpio/gpiolib-acpi.h +++ b/drivers/gpio/gpiolib-acpi.h @@ -18,6 +18,7 @@ struct acpi_device; * @pin_config: pin bias as provided by ACPI * @polarity: interrupt polarity as provided by ACPI * @triggering: triggering type as provided by ACPI + * @debounce: debounce timeout as provided by ACPI * @quirks: Linux specific quirks as provided by struct acpi_gpio_mapping */ struct acpi_gpio_info { @@ -27,6 +28,7 @@ struct acpi_gpio_info { int pin_config; int polarity; int triggering; + unsigned int debounce; unsigned int quirks; };