This is a note to let you know that I've just added the patch titled
gpio: twl4030: Fix regression for twl gpio output
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
gpio-twl4030-fix-regression-for-twl-gpio-output.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0b2aa8bed3e13892fcac77e4f50ec6e80125469d Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@xxxxxxxxxxx>
Date: Mon, 18 Nov 2013 15:22:49 -0800
Subject: gpio: twl4030: Fix regression for twl gpio output
From: Tony Lindgren <tony@xxxxxxxxxxx>
commit 0b2aa8bed3e13892fcac77e4f50ec6e80125469d upstream.
Commit c111feabe2e2 (gpio: twl4030: Cache the direction and output
states in private data) improved things in general, but caused a
regression for setting the GPIO output direction.
The change reorganized twl_direction_out() and twl_set() and swapped
the function names around in the process. While doing that, a bug got
introduced that's not obvious while reading the patch as it appears
as no change to the code.
The bug is we now call function twl4030_set_gpio_dataout() twice in
both twl_direction_out() and twl_set(). Instead, we should first
call twl_direction_out() in twl_direction_out() followed by
twl4030_set_gpio_dataout() in twl_set().
This regression probably has gone unnoticed for a long time as the
bootloader may have set the GPIO direction properly in many cases.
This fixes at least the LCD panel not turning on omap3 LDP for
example.
Cc: linux-gpio@xxxxxxxxxxxxxxx
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpio/gpio-twl4030.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/gpio/gpio-twl4030.c
+++ b/drivers/gpio/gpio-twl4030.c
@@ -354,17 +354,18 @@ static void twl_set(struct gpio_chip *ch
static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
{
struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
+ int ret = -EINVAL;
mutex_lock(&priv->mutex);
if (offset < TWL4030_GPIO_MAX)
- twl4030_set_gpio_dataout(offset, value);
+ ret = twl4030_set_gpio_direction(offset, 0);
priv->direction |= BIT(offset);
mutex_unlock(&priv->mutex);
twl_set(chip, offset, value);
- return 0;
+ return ret;
}
static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
Patches currently in stable-queue which might be from tony@xxxxxxxxxxx are
queue-3.12/arm-omap2-irq-am33xx-add-missing-register-check.patch
queue-3.12/gpio-twl4030-fix-regression-for-twl-gpio-output.patch
queue-3.12/arm-omap2-omap_device-maintain-sane-runtime-pm-status-around-suspend-resume.patch
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