6.12-stable review patch. If anyone has any objections, please let me know.
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From: Hans de Goede hdegoede@redhat.com
commit fdb1ada57cf8b8752cdf54f08709d76d74999544 upstream.
The _CRS ACPI resources table has 2 entries for the host wakeup GPIO, the first one being a regular GpioIo () resource while the second one is a GpioInt () resource for the same pin.
The acpi_gpio_mapping table used by vsc-tp.c maps the first Gpio () resource to "wakeuphost-gpios" where as the second GpioInt () entry is mapped to "wakeuphostint-gpios".
Using "wakeuphost" to request the GPIO as was done until now, means that the gpiolib-acpi code does not know that the GPIO is active-low as that info is only available in the GpioInt () entry.
Things were still working before due to the following happening:
1. Since the 2 entries point to the same pin they share a struct gpio_desc 2. The SPI core creates the SPI device vsc-tp.c binds to and calls acpi_dev_gpio_irq_get(). This does use the second entry and sets FLAG_ACTIVE_LOW in gpio_desc.flags . 3. vsc_tp_probe() requests the "wakeuphost" GPIO and inherits the active-low flag set by acpi_dev_gpio_irq_get()
But there is a possible scenario where things do not work:
1. - 3. happen as above 4. After requesting the "wakeuphost" GPIO, the "resetfw" GPIO is requested next, but its USB GPIO controller is not available yet, so this call returns -EPROBE_DEFER. 5. The gpio_desc for "wakeuphost" is put() and during this the active-low flag is cleared from gpio_desc.flags . 6. Later on vsc_tp_probe() requests the "wakeuphost" GPIO again, but now it is not marked active-low.
The difference can also be seen in /sys/kernel/debug/gpio, which contains the following line for this GPIO:
gpio-535 ( |wakeuphost ) in hi IRQ ACTIVE LOW
If the second scenario is hit the "ACTIVE LOW" at the end disappears and things do not work.
Fix this by requesting the GPIO through the "wakeuphostint" mapping instead which provides active-low info without relying on acpi_dev_gpio_irq_get() pre-populating this info in the gpio_desc.
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2316918 Signed-off-by: Hans de Goede hdegoede@redhat.com Reviewed-by: Stanislaw Gruszka stanislaw.gruszka@linux.intel.com Tested-by: Sakari Ailus sakari.ailus@linux.intel.com Fixes: 566f5ca97680 ("mei: Add transport driver for IVSC device") Cc: stable stable@kernel.org Link: https://lore.kernel.org/r/20250214212425.84021-1-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/misc/mei/vsc-tp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/misc/mei/vsc-tp.c +++ b/drivers/misc/mei/vsc-tp.c @@ -504,7 +504,7 @@ static int vsc_tp_probe(struct spi_devic if (ret) return ret;
- tp->wakeuphost = devm_gpiod_get(dev, "wakeuphost", GPIOD_IN); + tp->wakeuphost = devm_gpiod_get(dev, "wakeuphostint", GPIOD_IN); if (IS_ERR(tp->wakeuphost)) return PTR_ERR(tp->wakeuphost);