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 2ED6EC2BB41 for ; Wed, 17 Aug 2022 20:04:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241697AbiHQUED (ORCPT ); Wed, 17 Aug 2022 16:04:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241680AbiHQUDy (ORCPT ); Wed, 17 Aug 2022 16:03:54 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDA1C27B05 for ; Wed, 17 Aug 2022 13:03:52 -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 68DB56151E for ; Wed, 17 Aug 2022 20:03:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6340CC43470; Wed, 17 Aug 2022 20:03:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660766631; bh=SNZ70vt4bNjbtH48RRhcFsT0HkyKYDhAfV/NNF8Sj9I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=taN9Qch78MvSeXbDyWhIPR+suwZFNPzyZmAzLyaR8NSXf4mh7CdyLT7HVxlXTnPNq T/i1I8SetYLuOCZkc2llJ3tcbeIPqTr0ehmxYsJOjjVvF0c8+a7ajJ3QjE+b/9e+7f r9k6dPFiBV9QJP6TypHRyedePbioXwEtckP3Qdz+fIShsVIIW2fr3W2CxSGN7stVLq 5BRjY4Te5NT9sd8GO5i4YGbKHiZc/pOGu19BP1yEHJMFNT1LcwPOX82Or3HscGafKt bbMEGjFAPBlHqKea0D5eQu6L5hWRWQ1D1nfxltwTKwJPmDm9xuV6BlO/ijoCjxnYzR mRB3pVzkAtsrw== 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 v2 4/4] arm64: dts: armada-3720-turris-mox: Change comphy tx amplitude for 2500base-x mode Date: Wed, 17 Aug 2022 22:03:35 +0200 Message-Id: <20220817200335.911-5-kabel@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220817200335.911-1-kabel@kernel.org> References: <20220817200335.911-1-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