From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: grant.likely@secretlab.ca, linus.walleij@stericsson.com,
Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: [PATCH] gpio/langwell: re-read the IRQ status register after each iteration
Date: Thu, 10 May 2012 13:01:22 +0300 [thread overview]
Message-ID: <1336644082-14137-1-git-send-email-mika.westerberg@linux.intel.com> (raw)
Spotted by Grant Likely. The IRQ status register should be re-read after
each iteration. Otherwise the loop misses the interrupt if it gets raised
immediately after handled.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
This patch applies on top of my previous patch ("gpio: langwell: convert to
use irq_domain").
drivers/gpio/gpio-langwell.c | 4 +---
1 files changed, 1 insertions(+), 3 deletions(-)
diff --git a/drivers/gpio/gpio-langwell.c b/drivers/gpio/gpio-langwell.c
index b067357..a1c8754 100644
--- a/drivers/gpio/gpio-langwell.c
+++ b/drivers/gpio/gpio-langwell.c
@@ -250,11 +250,9 @@ static void lnw_irq_handler(unsigned irq, struct irq_desc *desc)
/* check GPIO controller to check which pin triggered the interrupt */
for (base = 0; base < lnw->chip.ngpio; base += 32) {
gedr = gpio_reg(&lnw->chip, base, GEDR);
- pending = readl(gedr);
- while (pending) {
+ while ((pending = readl(gedr))) {
gpio = __ffs(pending);
mask = BIT(gpio);
- pending &= ~mask;
/* Clear before handling so we can't lose an edge */
writel(mask, gedr);
generic_handle_irq(irq_find_mapping(lnw->domain,
--
1.7.9.1
next reply other threads:[~2012-05-10 10:00 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-10 10:01 Mika Westerberg [this message]
2012-05-10 12:16 ` [PATCH] gpio/langwell: re-read the IRQ status register after each iteration Linus Walleij
2012-05-10 20:34 ` Julia Lawall
2012-05-11 11:57 ` Linus Walleij
2012-05-10 22:35 ` Grant Likely
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