[PATCH] gpio/omap: fix off-mode bug: clear debounce clock enable mask on disable
From: Felipe Balbi <hidden>
Date: 2012-10-23 19:09:14
Also in:
linux-omap
Subsystem:
gpio subsystem, omap gpio driver, the rest · Maintainers:
Linus Walleij, Bartosz Golaszewski, Grygorii Strashko, Santosh Shilimkar, Kevin Hilman, Linus Torvalds
Hi, On Tue, Oct 23, 2012 at 11:09:31AM -0700, Kevin Hilman wrote:
From: Kevin Hilman <redacted> When debounce clocks are disabled, ensure that the banks dbck_enable_mask is cleared also. Otherwise, context restore on subsequent off-mode transition will restore previous value from the shadow copies (bank->context.debounce*) leading to mismatch state between driver state and hardware state. This was discovered when board code was doing gpio_request_one() gpio_set_debounce() gpio_free() which was leaving the GPIO debounce settings in a confused state. Then, enabling off mode causing bogus state to be restored, leaving GPIO debounce enabled which then prevented the CORE powerdomain from transitioning. Reported-by: Paul Walmsley <paul@pwsan.com> Cc: Igor Grinberg <redacted> Signed-off-by: Kevin Hilman <redacted>
looks like this deserves a Cc: stable at vger.kernel.org tag.
quoted hunk ↗ jump to hunk
--- Applies on v3.7-rc2, targetted for v3.7. drivers/gpio/gpio-omap.c | 1 + 1 file changed, 1 insertion(+)diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c index 94cbc84..dee2856 100644 --- a/drivers/gpio/gpio-omap.c +++ b/drivers/gpio/gpio-omap.c@@ -187,6 +187,7 @@ static inline void _gpio_dbck_disable(struct gpio_bank *bank) * to detect events and generate interrupts at least on OMAP3. */ __raw_writel(0, bank->base + bank->regs->debounce_en); + bank->dbck_enable_mask = 0;
shouldn't omap_gpio_restore_context() check for dbck_enabled instead of the mask ? I mean:
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 94cbc84..b3a39a7 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c@@ -1371,7 +1371,7 @@ static void omap_gpio_restore_context(struct gpio_bank *bank) bank->base + bank->regs->dataout); __raw_writel(bank->context.oe, bank->base + bank->regs->direction); - if (bank->dbck_enable_mask) { + if (bank->dbck_enabled) { __raw_writel(bank->context.debounce, bank->base + bank->regs->debounce); __raw_writel(bank->context.debounce_en,
the outcome would be the same, so it doesn't really matter. Just that, at least to me, it would look better. No strong feelings though. -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20121023/607d8ee1/attachment.sig>