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From: peter.ujfalusi@ti•com (Peter Ujfalusi)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 5/8] gpio: twl4030: Fix regression for twl gpio output
Date: Thu, 14 Nov 2013 11:45:51 +0200	[thread overview]
Message-ID: <52849BCF.6060203@ti.com> (raw)
In-Reply-To: <1384396537-3486-6-git-send-email-tony@atomide.com>

Hi Tony,

On 11/14/2013 04:35 AM, Tony Lindgren wrote:
> 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.

Thanks for catching this. I have a recollection that I have tested the GPIO
and it appeared to be working fine..

Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti•com>

> Cc: Linus Walleij <linus.walleij@linaro•org>
> Cc: Peter Ujfalusi <peter.ujfalusi@ti•com>
> Cc: linux-gpio at vger.kernel.org
> Signed-off-by: Tony Lindgren <tony@atomide•com>
> ---
> 
> If this looks OK, I'd like to merge this as a fix via arm-soc tree
> along with the other patches in this series as my later patches
> depend on patches in this series.
> 
> ---
>  drivers/gpio/gpio-twl4030.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-twl4030.c b/drivers/gpio/gpio-twl4030.c
> index 0c7e891..5738d5a 100644
> --- a/drivers/gpio/gpio-twl4030.c
> +++ b/drivers/gpio/gpio-twl4030.c
> @@ -354,17 +354,18 @@ static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
>  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)
> 


-- 
P?ter

  reply	other threads:[~2013-11-14  9:45 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-14  2:35 [PATCH 0/8] Various omap device tree usability fixes for v3.13 merge window Tony Lindgren
2013-11-14  2:35 ` [PATCH 1/8] net: smc91x: Fix device tree based configuration so it's usable Tony Lindgren
2013-11-14 11:03   ` Mark Rutland
2013-11-14 16:08     ` Tony Lindgren
2013-11-16 15:16       ` Tony Lindgren
2013-11-27 18:36         ` Tony Lindgren
2013-11-14  2:35 ` [PATCH 2/8] mmc: omap: Fix DMA configuration to not rely on device id Tony Lindgren
2013-11-18 18:47   ` Tony Lindgren
2013-11-26 23:33     ` Chris Ball
2013-11-26 23:52       ` Tony Lindgren
2013-11-27 20:57       ` Jarkko Nikula
2013-11-27 21:37         ` Tony Lindgren
2013-11-28 17:02           ` Jarkko Nikula
2013-11-29 16:34             ` Tony Lindgren
2013-11-27 21:47         ` Chris Ball
2013-11-27 21:59           ` Tony Lindgren
2013-11-28 16:13             ` Jarkko Nikula
2013-11-29 17:13               ` Tony Lindgren
2013-11-30  0:38   ` Joel Fernandes
2013-11-30 17:33     ` Tony Lindgren
2013-11-14  2:35 ` [PATCH 3/8] mmc: omap: Fix I2C dependency and make driver usable with device tree Tony Lindgren
2013-11-14 11:05   ` Mark Rutland
2013-11-14 17:25     ` Tony Lindgren
2013-11-26 23:34       ` Chris Ball
2013-11-14  2:35 ` [PATCH 4/8] i2c: omap: Fix missing device tree flags for omap2 Tony Lindgren
2013-11-14  6:58   ` Wolfram Sang
2013-11-14 17:34     ` Tony Lindgren
2013-11-14 17:49       ` Wolfram Sang
2013-11-14 17:53         ` Tony Lindgren
2013-11-14 11:07   ` Mark Rutland
2013-11-14 17:30     ` Tony Lindgren
2013-11-14  2:35 ` [PATCH 5/8] gpio: twl4030: Fix regression for twl gpio output Tony Lindgren
2013-11-14  9:45   ` Peter Ujfalusi [this message]
2013-11-14 17:37     ` Tony Lindgren
2013-11-18 22:45   ` Linus Walleij
2013-12-03 13:30   ` Roger Quadros
2013-12-09 13:09     ` Linus Walleij
2013-12-09 17:10       ` Tony Lindgren
2013-12-10 12:17         ` Linus Walleij
2013-12-10 15:20           ` Tony Lindgren
2013-11-14  2:35 ` [PATCH 6/8] gpio: twl4030: Fix passing of pdata in the device tree case Tony Lindgren
2013-11-18 18:27   ` Tony Lindgren
2013-11-18 22:46     ` Linus Walleij
2013-11-14  2:35 ` [PATCH 7/8] ARM: OMAP2+: Fix GPMC and simplify bootloader timings for 8250 and smc91x Tony Lindgren
2013-11-14  2:35 ` [PATCH 8/8] ARM: dts: Fix omap2 specific dtsi files by adding the missing entries Tony Lindgren
2013-11-14 23:08 ` [PATCH 9/8] i2c: Fix device tree binding for i2c-cbus-gpio Tony Lindgren
2013-11-15 18:49   ` Aaro Koskinen
2013-11-15 22:26   ` Wolfram Sang
2013-11-15 22:30     ` Tony Lindgren

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