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authorJohn Crispin <john@openwrt.org>2015-08-17 06:04:32 +0000
committerJohn Crispin <john@openwrt.org>2015-08-17 06:04:32 +0000
commit22b3e521b5ec4022717df7ef0c532b58aaca4abe (patch)
treecaa2bcb90a9e6eeeccf5af9e7d02849c0b59285b /target/linux/brcm2708/patches-4.1/0148-pinctrl-bcm2835-Clear-the-event-latch-register-when-.patch
parent98e122e4ccd533a5836e5dcb8a96d2d09180b8f0 (diff)
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brcm2708: update 4.1 patches
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> SVN-Revision: 46640
Diffstat (limited to 'target/linux/brcm2708/patches-4.1/0148-pinctrl-bcm2835-Clear-the-event-latch-register-when-.patch')
-rw-r--r--target/linux/brcm2708/patches-4.1/0148-pinctrl-bcm2835-Clear-the-event-latch-register-when-.patch37
1 files changed, 37 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.1/0148-pinctrl-bcm2835-Clear-the-event-latch-register-when-.patch b/target/linux/brcm2708/patches-4.1/0148-pinctrl-bcm2835-Clear-the-event-latch-register-when-.patch
new file mode 100644
index 0000000000..076ff5a969
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.1/0148-pinctrl-bcm2835-Clear-the-event-latch-register-when-.patch
@@ -0,0 +1,37 @@
+From 2a2dc4e5e4946e75b98c71eacc3660e913dbd302 Mon Sep 17 00:00:00 2001
+From: Jonathan Bell <jonathan@raspberrypi.org>
+Date: Tue, 30 Jun 2015 12:35:39 +0100
+Subject: [PATCH 148/148] pinctrl: bcm2835: Clear the event latch register when
+ disabling interrupts
+
+It's possible to hit a race condition if interrupts are generated on a GPIO
+pin when the IRQ line in question is being disabled.
+
+If the interrupt is freed, bcm2835_gpio_irq_disable() is called which
+disables the event generation sources (edge, level). If an event occurred
+between the last disabling of hard IRQs and the write to the event
+source registers, a bit would be set in the GPIO event detect register
+(GPEDSn) which goes unacknowledged by bcm2835_gpio_irq_handler()
+so Linux complains loudly.
+
+There is no per-GPIO mask register, so when disabling GPIO interrupts
+write 1 to the relevant bit in GPEDSn to clear out any stale events.
+
+Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>
+Acked-by: Stephen Warren <swarren@wwwdotorg.org>
+Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
+---
+ drivers/pinctrl/bcm/pinctrl-bcm2835.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c
++++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
+@@ -503,6 +503,8 @@ static void bcm2835_gpio_irq_disable(str
+
+ spin_lock_irqsave(&pc->irq_lock[bank], flags);
+ bcm2835_gpio_irq_config(pc, gpio, false);
++ /* Clear events that were latched prior to clearing event sources */
++ bcm2835_gpio_set_bit(pc, GPEDS0, gpio);
+ clear_bit(offset, &pc->enabled_irq_map[bank]);
+ spin_unlock_irqrestore(&pc->irq_lock[bank], flags);
+ }