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 617C51FC0EF; Mon, 2 Jun 2025 15:19:32 +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=1748877573; cv=none; b=AnxMbkxz+1sJSHIUKdgo3Sv9wfjHGvPuL9pujhNJ3gq51qJowaPuYTt64okSiAxzUC4cqM4xMlLBIrFeBzincc0FLBnAbIazM/ruaw4l7DQNvhlAhkF6cuzRPqAK7y1j/oj+G6UMIOfj+yt5tCThzsQduAE1yWXYmvJKtewgzq0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748877573; c=relaxed/simple; bh=UP9MXY0gHaO1YnnBPEO3izDVt+H6IN2I3ICXCntIDqA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=G9agyAmNCPpBYGQX3Qw+sL/KUeEkl8yTrEomLt84VDjTfOq8DOHW7ecluryoEURsFhg62K1TGuSecfYjAkSHfX4VzQQiqBsI5ZD2Ex/FwzL0xyodUTmM+CfEU5lnTgUSTH8OOjr0b1WtHXLRN+uzN/WppkmGPnXNM6YTn3jpMuI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2eWXSB1s; 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="2eWXSB1s" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70293C4CEEB; Mon, 2 Jun 2025 15:19:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748877572; bh=UP9MXY0gHaO1YnnBPEO3izDVt+H6IN2I3ICXCntIDqA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2eWXSB1sgjCH+lpkFqcNFeFTZHlylGoCgIRbiobsOSyhD6PYmbBJ7niB8zmKI2yOu iy0fksa3aCXk6KokFe+zh1ypi9pR7o2j0EZHvjNOfPJNKFEPv2VS9aeZZrvNG+lTmj fTrrnzOIYbGO+1KJkKv0uvjyg9P2h9qgOowk1DjM= 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 6.1 320/325] spi: spi-sun4i: fix early activation Date: Mon, 2 Jun 2025 15:49:56 +0200 Message-ID: <20250602134332.933296607@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134319.723650984@linuxfoundation.org> References: <20250602134319.723650984@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-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 6000d0761206c..6937f5c4d868f 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