From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6E5FC25B08 for ; Wed, 17 Aug 2022 19:32:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241484AbiHQTcz (ORCPT ); Wed, 17 Aug 2022 15:32:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236670AbiHQTcU (ORCPT ); Wed, 17 Aug 2022 15:32:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A71E5A5701 for ; Wed, 17 Aug 2022 12:31:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 014F5614A8 for ; Wed, 17 Aug 2022 19:31:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0D01C4347C; Wed, 17 Aug 2022 19:31:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660764696; bh=SNZ70vt4bNjbtH48RRhcFsT0HkyKYDhAfV/NNF8Sj9I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SkOaWUehiFg+GvygEMhrqAyB4Tt0u6BZbWBJC25DJsFB51eLopLOOunbUSxBq/yzp fJwrT4Nk3jEZJf011mniit1BiIyydgQno3tr5aA6AhWUnA3tLkDqidlUIbv+zTkHdv KrqWGbXhfJ1jINkNHlBCKKo/kC9a7oXnjUCjjjUQEniQmMf1ABgzGPIJ4HC4Ai3o/X dZTM1Ga/87yWTZd329aSvZOtMHMcY7uFv5iYF22OUpap7OpJwFlEdGU3F0xD8nVkkn 67RpshgzLjJj8A702Qku/xBaCAjppJap/icXN8gc+IlQN5/qRCmjPJNF/HyLywU6pi VTrsSb+/GBtFA== From: =?UTF-8?q?Marek=20Beh=C3=BAn?= To: Vinod Koul , Kishon Vijay Abraham I , Linux Phy , Gregory Clement Cc: Andy Shevchenko , Daniel Scally , Heikki Krogerus , Kees Cook , Sakari Ailus , linux-kernel@vger.kernel.org, pali@kernel.org, josef.schlehofer@nic.cz, =?UTF-8?q?Marek=20Beh=C3=BAn?= Subject: [PATCH linux-phy 4/4] arm64: dts: armada-3720-turris-mox: Change comphy tx amplitude for 2500base-x mode Date: Wed, 17 Aug 2022 21:31:19 +0200 Message-Id: <20220817193119.4463-5-kabel@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220817193119.4463-1-kabel@kernel.org> References: <20220817193119.4463-1-kabel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Change comphy transmit amplitude to 1025 mV for 2500base-x mode on comphy connected to Topaz. This fixes issue wherein if the 8b/10b encoded packet contains a long enough alternating sequence of bits (010101... or 101010...), which happens if the packet contains a sequence of 'J' or '\xb5' bytes, the packet may be lost when sent from A3720 to Topaz due to FCS error. The probability of loss grows with the number of 'J's with default transmit amplitude setting - with 114 'J's the probability is about 50%, with 125 'J's almost 100% of packets are lost. Fixes: 7109d817db2e ("arm64: dts: marvell: add DTS for Turris Mox") Signed-off-by: Marek Behún --- arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts index ada164d423f3..74a7ac1f8ecb 100644 --- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts +++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts @@ -181,6 +181,16 @@ ð1 { phys = <&comphy0 1>; }; +&comphy0 { + /* + * Set peak to peak transmit amplitude to 1025 mV to fix issue wherein + * a packet may be lost if it contains a long enough sequence of 'J' + * or '\xb5' bytes. + */ + tx-p2p-microvolt = <1025000>; + tx-p2p-microvolt-names = "2500base-x"; +}; + &sdhci0 { wp-inverted; bus-width = <4>; -- 2.35.1