Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757533AbbGGOiD (ORCPT ); Tue, 7 Jul 2015 10:38:03 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:52377 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754357AbbGGOh5 (ORCPT ); Tue, 7 Jul 2015 10:37:57 -0400 Message-ID: <559BE433.9020308@ti.com> Date: Tue, 7 Jul 2015 17:37:39 +0300 From: Roger Quadros User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Marc Kleine-Budde , , CC: , , , Subject: Re: [PATCH 1/2] net: can: c_can: Fix default pinmux glitch at init References: <1436279277-3386-1-git-send-email-rogerq@ti.com> <1436279277-3386-2-git-send-email-rogerq@ti.com> <559BE34F.8080508@pengutronix.de> <559BE3BE.2020608@ti.com> In-Reply-To: <559BE3BE.2020608@ti.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2824 Lines: 79 On 07/07/15 17:35, Roger Quadros wrote: > On 07/07/15 17:33, Marc Kleine-Budde wrote: >> On 07/07/2015 04:27 PM, Roger Quadros wrote: >>> From: "J.D. Schroeder" >>> >>> The previous change 3973c526ae9c (net: can: c_can: Disable pins when >>> CAN interface >>> is down) causes a slight glitch on the pinctrl settings when used. Since >>> commit ab78029 (drivers/pinctrl: grab default handles from device core), >>> the device core will automatically set the default pins. This causes >>> the pins to be momentarily set to the default and then to the sleep >>> state in register_c_can_dev(). By adding an optional "enable" state, >>> boards can set the default pin state to be disabled and avoid the >>> glitch when the switch from default to sleep first occurs. If the >>> "enable" state is not available c_can_pinctrl_select_state() falls >>> back to using the "default" pinctrl state. >>> >>> [Roger Q] - Forward port to v4.2 >>> >>> Signed-off-by: J.D. Schroeder >>> Signed-off-by: Roger Quadros >>> --- >>> drivers/net/can/c_can/c_can.c | 13 ++++++++++++- >>> 1 file changed, 12 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/net/can/c_can/c_can.c >>> b/drivers/net/can/c_can/c_can.c >>> index 041525d..66e98e7 100644 >>> --- a/drivers/net/can/c_can/c_can.c >>> +++ b/drivers/net/can/c_can/c_can.c >>> @@ -605,7 +605,18 @@ static int c_can_start(struct net_device *dev) >>> priv->can.state = CAN_STATE_ERROR_ACTIVE; >>> >>> /* activate pins */ >>> - pinctrl_pm_select_default_state(dev->dev.parent); >>> +#ifdef CONFIG_PINCTRL >> >> Please remove the ifdef, AFAICS there are static inline noop functions >> if CONFIG_PINCTRL switched off. > > yes, you are right. On second thoughts device->pins are not defined if CONFIG_PINCTRL is not set. so we can't remove the #ifdef. cheers, -roger > >> >>> + if (priv->device->pins) { >>> + struct pinctrl_state *s; >>> + >>> + /* Attempt to use "active" if available else use "default" */ >>> + s = pinctrl_lookup_state(priv->device->pins->p, "active"); >>> + if (!IS_ERR(s)) >>> + pinctrl_select_state(priv->device->pins->p, s); >>> + else >>> + pinctrl_pm_select_default_state(dev->dev.parent); >>> + } >>> +#endif >>> return 0; >>> } >>> >>> >> >> Marc >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/