From mboxrd@z Thu Jan 1 00:00:00 1970 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 2F93F1D8DFB; Mon, 2 Jun 2025 14:51:35 +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=1748875895; cv=none; b=uCha2FTjgivkJAfMlYY5Q5gStJKkQSPvXm1NGKKPzsM4d16NrcqaUTl8Lo9lJIBjoj8mQOfCrFqGv1BPJQDohyouM9ZrPTUY436qmxe6UhKscLZfEuo+4tSiJ2G3R5Gz2imGZj5EJ6Nk8TorHOoTaiIFdS0qIST6yy5R5SF1aYQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748875895; c=relaxed/simple; bh=T1D9m+JqfloIZObj/BuC2Fy8UTs6c25eFwJ/xZmpR8s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PSAv0HGJY8XzTfirU/7z10UwMDKptBozaUpph7jubqGQstZQQTYnPQok+pPVgeqnzE4TtJlgRdyFggre+1vSCzAJ/+QcbYJNt/a1+DakIL/DZ5XjpBLVCc8qmHqAg7CNK1V8l3Fs1rJ9QBfj6SpIG7++6a1Ps59eKe63mrCa++I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zte4fu5u; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zte4fu5u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 926BDC4CEEB; Mon, 2 Jun 2025 14:51:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748875895; bh=T1D9m+JqfloIZObj/BuC2Fy8UTs6c25eFwJ/xZmpR8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zte4fu5u8kTctUd95dsIPfjHGDzNHDUjew79MOSXZlqcBAy3Med8KdnspQZRa9J1s jXY7qU+z64RnJOUhl8NXV5UFDzrgjlDi7FYQ2DwD88tFJQZzBkIyvNV1YtTFblAJsI RBDx6v3bTpuhZ7srm7se1PWB9jAtHEsBxvlBUwmw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alessandro Grassi , Mark Brown , Sasha Levin Subject: [PATCH 5.10 265/270] spi: spi-sun4i: fix early activation Date: Mon, 2 Jun 2025 15:49:10 +0200 Message-ID: <20250602134318.173898927@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134307.195171844@linuxfoundation.org> References: <20250602134307.195171844@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alessandro Grassi [ Upstream commit fb98bd0a13de2c9d96cb5c00c81b5ca118ac9d71 ] The SPI interface is activated before the CPOL setting is applied. In that moment, the clock idles high and CS goes low. After a short delay, CPOL and other settings are applied, which may cause the clock to change state and idle low. This transition is not part of a clock cycle, and it can confuse the receiving device. To prevent this unexpected transition, activate the interface while CPOL and the other settings are being applied. Signed-off-by: Alessandro Grassi Link: https://patch.msgid.link/20250502095520.13825-1-alessandro.grassi@mailbox.org Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-sun4i.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c index 1fdfc6e6691d2..a8fba310d7004 100644 --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c @@ -263,6 +263,9 @@ static int sun4i_spi_transfer_one(struct spi_master *master, else reg |= SUN4I_CTL_DHB; + /* Now that the settings are correct, enable the interface */ + reg |= SUN4I_CTL_ENABLE; + sun4i_spi_write(sspi, SUN4I_CTL_REG, reg); /* Ensure that we have a parent clock fast enough */ @@ -403,7 +406,7 @@ static int sun4i_spi_runtime_resume(struct device *dev) } sun4i_spi_write(sspi, SUN4I_CTL_REG, - SUN4I_CTL_ENABLE | SUN4I_CTL_MASTER | SUN4I_CTL_TP); + SUN4I_CTL_MASTER | SUN4I_CTL_TP); return 0; -- 2.39.5