Re: [PATCH v6 00/13] OMAP: GPIO: Implement GPIO in hwmod way

From: Kevin Hilman <khilman@deeprootsystems.com>
To: "Varadarajan, Charulatha" <charu@ti.com>
Cc: "tony@atomide.com" <tony@atomide.com>,
	"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
	"paul@pwsan.com" <paul@pwsan.com>,
	"Cousson, Benoit" <b-cousson@ti.com>,
	"Nayak, Rajendra" <rnayak@ti.com>,
	"Basak, Partha" <p-basak2@ti.com>
Subject: Re: [PATCH v6 00/13] OMAP: GPIO: Implement GPIO in hwmod way
Date: Wed, 22 Sep 2010 16:11:39 -0700	[thread overview]
Message-ID: <87wrqd74r8.fsf@deeprootsystems.com> (raw)
In-Reply-To: <87bp7qfx6g.fsf@deeprootsystems.com> (Kevin Hilman's message of "Tue, 21 Sep 2010 17:18:15 -0700")

Kevin Hilman <khilman@deeprootsystems.com> writes:

[...]

> I also just tested on n900 which has lots of GPIOs configured.  On this
> platform, suspend doesn't hit RET because both GPIO3 and GPIO4 are still
> enabled.  

OK, I found the bug on n900, and you're off the hook for this one. :)
It's an existing bug and the problem exists before applying your series.

See patch below for description, and I'll be posting/queuing this patch
in pm-next (included in pm-core)

Kevin


>From 9a0cc83c1199d802784ee2e4d249611231117fa1 Mon Sep 17 00:00:00 2001
From: Kevin Hilman <khilman@deeprootsystems.com>
Date: Wed, 22 Sep 2010 16:06:27 -0700
Subject: [PATCH] OMAP: GPIO: ensure debounce clocks are disabled during idle/suspend

If a GPIO bank has more than one GPIO with debounce enabled, the
debounce clock will not be fully disabled before going to
idle/suspend.

In the idle path, we just do a single clk_disable() of the bank's
debounce clock.  If there are multiple debounce-enabled GPIOs in the
bank, that clocks usage count will be > 1, so the clk_disable() will
not actually disable the clock.

So the fix is to clk_disable() for every debounce-enabled GPIO in the
bank (and an equivalent clk_enable() of course.)

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
---
 arch/arm/plat-omap/gpio.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm/plat-omap/gpio.c b/arch/arm/plat-omap/gpio.c
index 7951eef..5d38d62 100644
--- a/arch/arm/plat-omap/gpio.c
+++ b/arch/arm/plat-omap/gpio.c
@@ -2085,8 +2085,9 @@ void omap2_gpio_prepare_for_idle(int power_state)
 	for (i = min; i < gpio_bank_count; i++) {
 		struct gpio_bank *bank = &gpio_bank[i];
 		u32 l1, l2;
-
-		if (bank->dbck_enable_mask)
+		int j;
+ 
+		for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
 			clk_disable(bank->dbck);
 
 		if (power_state > PWRDM_POWER_OFF)
@@ -2152,8 +2153,9 @@ void omap2_gpio_resume_after_idle(void)
 	for (i = min; i < gpio_bank_count; i++) {
 		struct gpio_bank *bank = &gpio_bank[i];
 		u32 l, gen, gen0, gen1;
-
-		if (bank->dbck_enable_mask)
+		int j;
+ 
+		for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
 			clk_enable(bank->dbck);
 
 		if (!workaround_enabled)
-- 
1.7.2.1

