From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C33913DDB03; Tue, 21 Jul 2026 22:42:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784673748; cv=none; b=nfRBne7z4E/unT02G49tjjUKcc5x7PLfilbqabalh/+YH2AGnas5RWWXQAVRUHQZwQ2sAWUd6ji/hAxi7SdabJyn41+dZW30yIZ1ZSlm+zGkYa/OvbKSLKw0ZyaB+l50VbPOQ7LWYM3wsKlqYSNmgobQP9azquzZdB5F1bAAB6k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784673748; c=relaxed/simple; bh=RxYsiQP8kq8WcX4Wiu5TBYeE+KzuGRPuMyC04vTe9lo=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=XdD8jxPCCflOBaBT6E6QEdp+Mhl0StVkuDX1jz4gq9aGk3HGqLwZTLyOjLF4D/UIoBWKT3YMn5DSSPJHW9qkLVtbIC9eJ26oMKfLtG1eGQmP/530YwrxkseTL9BLiz6QEyeri8xaMay40UYLRdxeNiUjdxd5b84yBLwDOd4QcZY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=jJEHv73h; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="jJEHv73h" 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 AE9C41476; Tue, 21 Jul 2026 15:42:20 -0700 (PDT) Received: from ryzen.lan (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 15AD93F86F; Tue, 21 Jul 2026 15:42:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784673744; bh=RxYsiQP8kq8WcX4Wiu5TBYeE+KzuGRPuMyC04vTe9lo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jJEHv73hO6HQ086lu5xbbitXLOIGvcROEcTiIkVYUuD2o4T+l39wdKV8aezTQckJT DT1haVSH+RvItnWnU7gy41xC2ZW81zMcRGrrE40Wql6Qt0dl4rcQ5ufj83RXNKeajk i3dySNQ3QBnxXoJwt+6eL15DwX8atYc+Sxa1mz3g= Date: Wed, 22 Jul 2026 00:38:36 +0200 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: Re: [PATCH] arm64: dts: allwinner: a523: x96qpro+: overvolting eMMC Message-ID: <20260722003836.4677a33b@ryzen.lan> In-Reply-To: <20260720213832.3763-1-andre.przywara@arm.com> References: <20260720213832.3763-1-andre.przywara@arm.com> Organization: Arm Ltd. X-Mailer: Claws Mail 4.4.0 (GTK 3.24.31; x86_64-slackware-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 20 Jul 2026 23:38:32 +0200 Andre Przywara wrote: Hi, > 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. So for the records: please disregard this patch, it was more voodoo than a proper fix. As Sashiko pointed out, this slight voltage bump changes the GPIO bank withstand voltage, which turned out to be the actual culprit: the encoding was wrong, and the new voltage here now changed the value to inadvertently use the right bit setting. I will send another patch to fix this properly. Cheers, Andre > > 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"; > }; >