From nobody Wed Sep 10 01:55:25 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 295A41C07C4; Mon, 8 Sep 2025 19:50:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757361027; cv=none; b=S5Ju4KjdCVrkpoiPj0TPRiJXFtS0gN8uHoO5Ein8ymnjrtqTusYfyGkTdTDx1UZOs4Y/wA83tizb3oZff6UqgF5ip+OhEYAanoYa7LU7M++ZpzNarn1Z0Dq7yd8UWNLZ0PXrOuSWTyFcmOjtKaEy05zlyclSfV5adb1GpQL/02Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757361027; c=relaxed/simple; bh=Xa2A8wUs8DU/Qpi2eBoE6S8SjRM3jIuTJh0HvFOCRxg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=ms1FhqPyKlknzog3/ys9GoLbAHmbn5ZyXhTzt/ZBVO4oz3vXw0v5OKZzoQYjYsIh5LsQkVAKGTOE40uWlp6kxkMYxRxbPvVx3/1tnnTwN1jHYDQ41ke7XzbH5/g/x7Z2nY3GuUWhXn6Vdny10HrQsxLqJwzA1/rbHYQXsWkD3RU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oTzG4AlD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oTzG4AlD" Received: by smtp.kernel.org (Postfix) with ESMTPS id 97FBCC4CEF1; Mon, 8 Sep 2025 19:50:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757361026; bh=Xa2A8wUs8DU/Qpi2eBoE6S8SjRM3jIuTJh0HvFOCRxg=; h=From:Date:Subject:To:Cc:Reply-To:From; b=oTzG4AlDbpncPrHEebeStdQ+k/OZYSVISXsp0J8Ti0XyTpL8mYdFX7GqqOTijrHnj PC7zEqRFkWk+SCisRBfiue6QvyXrr+EAFA3oLof3us3TFPjReLHjO38YW9xKyZM3b3 1FCw1pZ8v5dcbU3kNuiwNY7jPCAPaIQMtG3okicuHft5Us1vQ7EQ+rzpsrwzji3Onn Lr7qa2YwlQHQzF6gAolmL6p+IMdP2m4bF0Hjz7vG12HcMhMgjtme9JWQsnxx1JjyL4 FgT5QHTfEiixv/qoY6NqrNaDhG6ikTr1xb+cTHOtZQ/Ul+ryhtI81kHKRAA+WHmDGG nWChdMTLZ+v1Q== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F232CAC582; Mon, 8 Sep 2025 19:50:26 +0000 (UTC) From: Valerio Setti via B4 Relay Date: Mon, 08 Sep 2025 21:50:03 +0200 Subject: [PATCH v2] arm64: dts: amlogic: gxbb-odroidc2: remove UHS capability for SD card 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="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250908-fix-reboot-v2-1-354d0e57c855@baylibre.com> X-B4-Tracking: v=1; b=H4sIAGozv2gC/23MTQqDMBCG4avIrDtlEvwhXfUe4iKmYx1oTUkkV CR3b3Td5TvD9+wQOQhHuFU7BE4SxS8l9KUCN9vlySiP0qBJN2Sow0m+GHj0fkWqmSZnlLFMUAa fwOV7Yv1Qepa4+rCddlLH9S+TFCrsWmoPSzc130e7vWQMfHX+DUPO+QcGgIQ9pwAAAA== X-Change-ID: 20250907-fix-reboot-04e0fc919ae0 To: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, Valerio Setti X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=2045; i=vsetti@baylibre.com; h=from:subject:message-id; bh=BJc4SXxGYBhMfaPaAFk61MykLFrvMDIrqRdHH0rt9IY=; b=owGbwMvMwCF2z3ty7kUrRgbG02pJDBn7jRuDXn3+sOHcgT2cDKu9ThrvSJgZ9VuAP9956mm9K rNPfIqNHaUsDGIcDLJiiiws0+/9LihVe2iccLIAZg4rE8gQBi5OAZiIdhUjQ8eu7/dYbVV89FJ8 JDoFqtsmSq7tVWzIrV2loFGjF6IjzvDfZ97m1ZYLFvRJ2yT5vAq8z7zmp3f339s5Zzv4zBP3y/5 jAQA= X-Developer-Key: i=vsetti@baylibre.com; a=openpgp; fpr=0497DEFB707526E13360C970DE4B936DD13A0100 X-Endpoint-Received: by B4 Relay for vsetti@baylibre.com/default with auth_id=515 X-Original-From: Valerio Setti Reply-To: vsetti@baylibre.com From: Valerio Setti This is meant to resolve reboot not working on this board. The problem is as follows. In order to be able to switch from HS to UHS mode the bus voltage needs to be reduced from 3.3V down to 1.8V and this is achieved by the "vqmmc-supply" regulator. The ROM bootloader is only able to manage the card in HS mode (3.3V) and the switch HS->UHS happen at boottime in the kernel. The problem appears when the reboot command is issued or watchdog expires because in this case the "vqmmc-supply" voltage is not returned back at 3.3V before rebooting the board so the ROM bootloader will be completely stuck. Therefore this commit removes all UHS modes which would cause "vqmmc-summply" to switch from 3.3V to 1.8V. In terms of performance the main drawback of this commit is limiting the SD card bus speed to HS (25 MB/s) instead of UHS DDR50 (50 MB/s). However this comes with the benefit of being able to reboot the board, so it sounds like a reasonable compromise. Reviewed-by: Jerome Brunet Signed-off-by: Valerio Setti --- Changes in v2: - Re-added vqmmc-supply to sd_emmc_b node. - Link to v1: https://lore.kernel.org/r/20250907-fix-reboot-v1-1-7606fc9125= 4e@baylibre.com --- arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts b/arch/arm= 64/boot/dts/amlogic/meson-gxbb-odroidc2.dts index 959bd8d77a82ebc78c5e0592d7613e692e4ede4e..12e26f99d4f080a216e305981dc= 4291a49063b60 100644 --- a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts +++ b/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts @@ -348,10 +348,6 @@ &sd_emmc_b { =20 bus-width =3D <4>; cap-sd-highspeed; - sd-uhs-sdr12; - sd-uhs-sdr25; - sd-uhs-sdr50; - sd-uhs-ddr50; max-frequency =3D <100000000>; disable-wp; =20 --- base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585 change-id: 20250907-fix-reboot-04e0fc919ae0 Best regards, --=20 Valerio Setti