From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: [PATCH v2] gpio/omap: fix off-mode bug: clear debounce clock enable mask on free/reset Date: Wed, 24 Oct 2012 10:10:41 -0700 Message-ID: <1351098641-23917-1-git-send-email-khilman@deeprootsystems.com> Return-path: Received: from mail-da0-f46.google.com ([209.85.210.46]:58310 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756417Ab2JXRKo (ORCPT ); Wed, 24 Oct 2012 13:10:44 -0400 Received: by mail-da0-f46.google.com with SMTP id n41so339176dak.19 for ; Wed, 24 Oct 2012 10:10:44 -0700 (PDT) Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Linus Walleij , Felipe Balbi , linux-omap@vger.kernel.org Cc: Paul Walmsley , linux-arm-kernel@lists.infradead.org, Igor Grinberg , Grazvydas Ignotas From: Kevin Hilman When a GPIO bank is freed or shutdown, 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. If that GPIO bank is subsequently used with off-mode enabled, bogus state would be restored, leaving GPIO debounce enabled which then prevented the CORE powerdomain from transitioning. To fix, ensure that bank->dbck_enable_mask is cleared when the bank is freed/shutdown so debounce state doesn't persist. Special thanks to Grazvydas Ignotas for pointing out a bug in an earlier version that would've disabled debounce on any runtime PM transition. Reported-by: Paul Walmsley Cc: Igor Grinberg Cc: Grazvydas Ignotas Signed-off-by: Kevin Hilman --- v2: only clear mask in free/shutdown, not in runtime PM paths, clarified changelog Applies on v3.7-rc2. 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..113b167 100644 --- a/drivers/gpio/gpio-omap.c +++ b/drivers/gpio/gpio-omap.c @@ -539,6 +539,7 @@ static void _reset_gpio(struct gpio_bank *bank, int gpio) _set_gpio_irqenable(bank, gpio, 0); _clear_gpio_irqstatus(bank, gpio); _set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), IRQ_TYPE_NONE); + bank->dbck_enable_mask = 0; } /* Use disable_irq_wake() and enable_irq_wake() functions from drivers */ -- 1.8.0