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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 505A4C44520 for ; Mon, 20 Jul 2026 21:42:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=9nHFRwj5WZMgtxSElXWFmj51/p6cjmuUXtJwmUNM5s8=; b=seP/+gW8pz92n/IH4bSnFG8nPW eKBA60DDyZX5TP91CJrHEuSwgglzvEY8qrcoc+nyZ0BRmOII8Ri71PWb39MOSXgJE+Clw/ltTysgQ ka7kvAPxNPz6wfBAo8beLRpaDmmWxnBdkFVidoMQgxXBphA8u+EkLexvd/QJ77rOUB4rG+Z9OWX4B iUjSwIkbios0HkiX82msl9WRT1ekwVovLPh+jAyGSAXqEYQZWsOvNyd87LToSPGDOS/7Q80yfpZtA by0EDzRURqlTatFkeVawuTke2BUllzuwDY10kTX5eBWCD/GNd8PbnUKruqzGEDzt1Fm+pqYT1K5em gKJXsQUw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wlvkp-00000007yLC-0sTO; Mon, 20 Jul 2026 21:42:27 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wlvkm-00000007yKH-1Gef for linux-arm-kernel@lists.infradead.org; Mon, 20 Jul 2026 21:42:26 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A3366143D; Mon, 20 Jul 2026 14:42:17 -0700 (PDT) Received: from ryzen.fritz.box (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9DC563F66F; Mon, 20 Jul 2026 14:42:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784583741; bh=7GPCEpWSp6hdvoiZp/dWDlRlQZkpNncKgtqSVs5WpVQ=; h=From:To:Cc:Subject:Date:From; b=l8iAgLJzV7Gh3mwE/JMxyp/TMqv1GUgNiObXadU2jzw1/5vwKGwxnPdQewXZ9dYDu WjFH5fDtXjJQN8vlY6tcX3U9ypgFZk1wmHI8SjrQSnCnB7AGmkgjh6OmhIOtWeLD24 /eUxAXDjbLj0L+RW23StDNOoNAUYlriflwcAUjpE= From: Andre Przywara To: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH] arm64: dts: allwinner: a523: x96qpro+: overvolting eMMC Date: Mon, 20 Jul 2026 23:38:32 +0200 Message-ID: <20260720213832.3763-1-andre.przywara@arm.com> X-Mailer: git-send-email 2.46.4 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260720_144224_468548_E114A17A X-CRM114-Status: GOOD ( 12.89 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On the X96QPro+ TV box, the eMMC wasn't working properly: the chip would be detected, but most requests failed, leaving it unusable. Some "solutions" were circulating downstream, one "popular" one is severely limiting the clock frequency, with a drastic performance impact. Instead slightly bumping the I/O voltage on PortC from the canonical 1.8V to 1.9V seemed to do the trick: the eMMC now works and reaches the expected 120MB/s performance. Adjust the respective regulator voltage in the .dts to enable eMMC operation on that device. Signed-off-by: Andre Przywara --- Hi, I am not super happy with this patch, but it seems to be a pragmatic and the least hacky solution I have seen. Cheers, Andre arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts b/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts index a96927fbdadd5..5636e95312218 100644 --- a/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts +++ b/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts @@ -194,8 +194,8 @@ reg_bldo4: bldo4 { reg_cldo1: cldo1 { regulator-always-on; - regulator-min-microvolt = <1800000>; - regulator-max-microvolt = <1800000>; + regulator-min-microvolt = <1900000>; + regulator-max-microvolt = <1900000>; regulator-name = "vcc-codec-sd"; }; -- 2.46.4