From patchwork Tue Dec 3 13:30:11 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roger Quadros X-Patchwork-Id: 3276031 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 1D8B19F373 for ; Tue, 3 Dec 2013 13:31:15 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 43F5D2022D for ; Tue, 3 Dec 2013 13:31:10 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D852F2018E for ; Tue, 3 Dec 2013 13:31:08 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vnq3q-0006me-1o; Tue, 03 Dec 2013 13:30:46 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vnq3j-0003nO-Bs; Tue, 03 Dec 2013 13:30:39 +0000 Received: from arroyo.ext.ti.com ([192.94.94.40]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vnq3g-0003mP-JL for linux-arm-kernel@lists.infradead.org; Tue, 03 Dec 2013 13:30:37 +0000 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id rB3DUD7X032547; Tue, 3 Dec 2013 07:30:13 -0600 Received: from DLEE70.ent.ti.com (dlee70.ent.ti.com [157.170.170.113]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id rB3DUDC2003424; Tue, 3 Dec 2013 07:30:13 -0600 Received: from dflp32.itg.ti.com (10.64.6.15) by DLEE70.ent.ti.com (157.170.170.113) with Microsoft SMTP Server id 14.2.342.3; Tue, 3 Dec 2013 07:30:13 -0600 Received: from [172.24.112.104] (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id rB3DUBSK021853; Tue, 3 Dec 2013 07:30:11 -0600 Message-ID: <529DDCE3.5020902@ti.com> Date: Tue, 3 Dec 2013 15:30:11 +0200 From: Roger Quadros User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.1.1 MIME-Version: 1.0 To: Tony Lindgren , , Subject: Re: [PATCH 5/8] gpio: twl4030: Fix regression for twl gpio output References: <1384396537-3486-1-git-send-email-tony@atomide.com> <1384396537-3486-6-git-send-email-tony@atomide.com> In-Reply-To: <1384396537-3486-6-git-send-email-tony@atomide.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131203_083036_722844_D7B328A0 X-CRM114-Status: GOOD ( 31.06 ) X-Spam-Score: -6.9 (------) Cc: Peter Ujfalusi , linux-gpio@vger.kernel.org, Linus Walleij X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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. > > Cc: Linus Walleij > Cc: Peter Ujfalusi > Cc: linux-gpio@vger.kernel.org > Signed-off-by: Tony Lindgren > --- > > 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. This patch causes a regression with LED outputs (GPO) on twl4030 on 3.13-rc2. As one of the LED GPO is used for USB host on beagleboard, it will cause failure of USB host probe. I'll explain why below. > > --- > 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); twl_direction_out() is supposed to return 0 on success and non-zero only on failure. for (offset >= TWL4030_GPIO_MAX) i.e. LED output case we now return -EINVAL, which causes the LED GPO set_direction_out to fail. LED outputs are always outputs so this function shouldn't fail. > > 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) > Below is a proposed fix for this. From 7c36c8952ee3c7220ea21396cd3f84a1f9e9ea73 Mon Sep 17 00:00:00 2001 From: Roger Quadros Date: Tue, 3 Dec 2013 15:24:05 +0200 Subject: [PATCH] gpio: twl4030: Fix regression for twl gpio LED output Commit 0b2aa8be introduced a regression that causes failure in setting LED GPO direction to OUT. This causes USB host probe failures for Beagleboard C4. [ 2.075469] platform usb_phy_gen_xceiv.2: Driver usb_phy_gen_xceiv requests probe deferral [ 2.090454] hsusb2_vcc: Failed to request enable GPIO510: -22 [ 2.100982] reg-fixed-voltage reg-fixed-voltage.0.auto: Failed to register regulator: -22 [ 2.109954] reg-fixed-voltage: probe of reg-fixed-voltage.0.auto failed with error -22 direction_out/direction_in must return 0 if the operation succeeded. Signed-off-by: Roger Quadros --- drivers/gpio/gpio-twl4030.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/gpio/gpio-twl4030.c b/drivers/gpio/gpio-twl4030.c index b97d6a6..0999ed1 100644 --- a/drivers/gpio/gpio-twl4030.c +++ b/drivers/gpio/gpio-twl4030.c @@ -294,13 +294,13 @@ out: static int twl_direction_in(struct gpio_chip *chip, unsigned offset) { struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); - int ret; + int ret = 0; mutex_lock(&priv->mutex); if (offset < TWL4030_GPIO_MAX) - ret = twl4030_set_gpio_direction(offset, 1); + twl4030_set_gpio_direction(offset, 1); else - ret = -EINVAL; + ret = -EINVAL; /* LED outputs can't be set as input */ if (!ret) priv->direction &= ~BIT(offset); @@ -354,18 +354,21 @@ 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) - ret = twl4030_set_gpio_direction(offset, 0); + twl4030_set_gpio_direction(offset, 0); + + /* + * LED gpio's i.e. offset >= TWL4030_GPIO_MAX are always output + */ priv->direction |= BIT(offset); mutex_unlock(&priv->mutex); twl_set(chip, offset, value); - return ret; + return 0; } static int twl_to_irq(struct gpio_chip *chip, unsigned offset)