From patchwork Tue Aug 10 17:29:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 495101 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18CC7C4320A for ; Tue, 10 Aug 2021 17:34:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02E69610A0 for ; Tue, 10 Aug 2021 17:34:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232707AbhHJRe6 (ORCPT ); Tue, 10 Aug 2021 13:34:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:40914 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232772AbhHJRe0 (ORCPT ); Tue, 10 Aug 2021 13:34:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 45D1061076; Tue, 10 Aug 2021 17:34:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628616843; bh=19XAj8CpkGRIQOjZXdON8Swuu6WXy9RgZW6TRI9rJrA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ctYzIa4Fm32B91XNZ8bJWu0RP+eilDmdP/hkYXZvGj+FF2iOZVDFauaRCrfcKgWTk kHHJ4RvC2xydeyuVUi9uZ3Lk3h+fI4XPkVKDD7nPB4voKfIPrwlJt2WDqfn5LZ84mm VmeqPoO7pJTQkoBcnzOlIpQ0Q8e2EjMHC2TDPluw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maxime Chevallier , =?utf-8?q?Herv=C3=A9_Codina?= , "Russell King (Oracle)" , Shawn Guo , Sasha Levin Subject: [PATCH 5.4 06/85] ARM: dts: imx6qdl-sr-som: Increase the PHY reset duration to 10ms Date: Tue, 10 Aug 2021 19:29:39 +0200 Message-Id: <20210810172948.420988038@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210810172948.192298392@linuxfoundation.org> References: <20210810172948.192298392@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Maxime Chevallier [ Upstream commit fd8e83884fdd7b5fc411f201a58d8d01890198a2 ] The AR803x PHY used on this modules seems to require the reset line to be asserted for around 10ms in order to avoid rare cases where the PHY gets stuck in an incoherent state that prevents it to function correctly. The previous value of 2ms was found to be problematic on some setups, causing intermittent issues where the PHY would be unresponsive every once in a while on some sytems, with a low occurrence (it typically took around 30 consecutive reboots to encounter the issue). Bumping the delay to the 10ms makes the issue dissapear, with more than 2500 consecutive reboots performed without the issue showing-up. Fixes: 208d7baf8085 ("ARM: imx: initial SolidRun HummingBoard support") Signed-off-by: Maxime Chevallier Tested-by: Hervé Codina Reviewed-by: Russell King (Oracle) Signed-off-by: Shawn Guo Signed-off-by: Sasha Levin --- arch/arm/boot/dts/imx6qdl-sr-som.dtsi | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm/boot/dts/imx6qdl-sr-som.dtsi b/arch/arm/boot/dts/imx6qdl-sr-som.dtsi index 6d7f6b9035bc..f2649241167e 100644 --- a/arch/arm/boot/dts/imx6qdl-sr-som.dtsi +++ b/arch/arm/boot/dts/imx6qdl-sr-som.dtsi @@ -54,7 +54,13 @@ pinctrl-names = "default"; pinctrl-0 = <&pinctrl_microsom_enet_ar8035>; phy-mode = "rgmii-id"; - phy-reset-duration = <2>; + + /* + * The PHY seems to require a long-enough reset duration to avoid + * some rare issues where the PHY gets stuck in an inconsistent and + * non-functional state at boot-up. 10ms proved to be fine . + */ + phy-reset-duration = <10>; phy-reset-gpios = <&gpio4 15 GPIO_ACTIVE_LOW>; status = "okay"; };