[PATCH] gpio/omap: fix off-mode bug: clear debounce clock enable mask on disable
From: Grazvydas Ignotas <hidden>
Date: 2012-10-24 12:02:30
Also in:
linux-omap
On Tue, Oct 23, 2012 at 9:09 PM, Kevin Hilman [off-list ref] 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 doesn't look right to me, aren't you effectively disabling debounce forever here? _gpio_dbck_disable is called from omap_gpio_runtime_suspend() and nothing will ever restore dbck_enable_mask back to what it was set by _set_gpio_debounce and debounce functionality is lost.
quoted hunk ↗ jump to hunk
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> --- 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; clk_disable(bank->dbck); bank->dbck_enabled = false; --1.8.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
-- Gra?vydas