Hi,
On Tue, Oct 23, 2012 at 11:09:31AM -0700, Kevin Hilman wrote:
> From: Kevin Hilman <khilman@xxxxxx>
>
> 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@xxxxxxxxx>
> Cc: Igor Grinberg <grinberg@xxxxxxxxxxxxxx>
> Signed-off-by: Kevin Hilman <khilman@xxxxxx>
looks like this deserves a Cc: stable@xxxxxxxxxxxxxxx tag.
> ---
> 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
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