From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758907Ab3LFOUx (ORCPT ); Fri, 6 Dec 2013 09:20:53 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:43615 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161082Ab3LFM76 (ORCPT ); Fri, 6 Dec 2013 07:59:58 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: linux-gpio@vger.kernel.org, Tony Lindgren , Luis Henriques Subject: [PATCH 3.11 022/272] gpio: twl4030: Fix regression for twl gpio output Date: Fri, 6 Dec 2013 12:55:11 +0000 Message-Id: <1386334761-25517-23-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1386334761-25517-1-git-send-email-luis.henriques@canonical.com> References: <1386334761-25517-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Tony Lindgren 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@vger.kernel.org Reviewed-by: Peter Ujfalusi Acked-by: Linus Walleij Signed-off-by: Tony Lindgren Signed-off-by: Luis Henriques --- 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 4d330e3..ed1d10a 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) -- 1.8.3.2