From 40379b0ec64d8ff17b4d34f261224fb72ceac9db Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Sat, 15 Jun 2019 19:13:30 +0200 Subject: [PATCH] apm821xx: fix bogus key-presses on boot "There are often transient line events when the system is powered up and initialized and it is often necessary for the gpio_chip driver to clear any interrupt flags in hardware before setting up the gpio chip, especially the irqchip portions of it." This patch adds a fix for the APM821XX's interrupt controller to clear any bogus pending toggled interrupts that happens on various APM821XX boards on boot. The patch also changes the debouce-interval from the default 5ms debounce interval to 60ms all around. The default setting caused on occasions that the button state became stuck in a pressed state, even though the button was released. Signed-off-by: Christian Lamparter (backported from commit 971f31bedcad0a954a4a4e79140346cc896d352e) --- ...clear-pending-interrupt-after-irq-ty.patch | 30 +++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 target/linux/apm821xx/patches-4.14/100-powerpc-4xx-uic-clear-pending-interrupt-after-irq-ty.patch diff --git a/target/linux/apm821xx/patches-4.14/100-powerpc-4xx-uic-clear-pending-interrupt-after-irq-ty.patch b/target/linux/apm821xx/patches-4.14/100-powerpc-4xx-uic-clear-pending-interrupt-after-irq-ty.patch new file mode 100644 index 0000000000..ee4eeb6963 --- /dev/null +++ b/target/linux/apm821xx/patches-4.14/100-powerpc-4xx-uic-clear-pending-interrupt-after-irq-ty.patch @@ -0,0 +1,30 @@ +From 9b84ad676e248a3e3c81db7f5d39e1739b3780aa Mon Sep 17 00:00:00 2001 +From: Christian Lamparter +Date: Sat, 15 Jun 2019 16:35:26 +0200 +Subject: [PATCH] powerpc/4xx/uic: clear pending interrupt after irq type/pol + change + +When testing out gpio-keys with a button, a spurious +interrupt (and therefore a key press or release event) +gets triggered as soon as the driver enables the irq +line for the first time. + +This patch clears any potential bogus generated interrupt +that was caused by the switching of the associated irq's +type and polarity. + +Signed-off-by: Christian Lamparter +--- + arch/powerpc/platforms/4xx/uic.c | 1 + + 1 file changed, 1 insertion(+) + +--- a/arch/powerpc/platforms/4xx/uic.c ++++ b/arch/powerpc/platforms/4xx/uic.c +@@ -158,6 +158,7 @@ static int uic_set_irq_type(struct irq_d + + mtdcr(uic->dcrbase + UIC_PR, pr); + mtdcr(uic->dcrbase + UIC_TR, tr); ++ mtdcr(uic->dcrbase + UIC_SR, ~mask); + + raw_spin_unlock_irqrestore(&uic->lock, flags); + -- 2.30.2