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 AB1E9C2D0CD for ; Mon, 19 May 2025 21:26:26 +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:References:In-Reply-To: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:List-Owner; bh=7gDsitpM17TiwDUqIdNUahaf4zAU3NxGd0pNiaiOiuQ=; b=L6fyv1mFOhu5UmRLzpgSHEB2O0 6n6/zp8QMIR6pmXIis76IwBiOcQNJDd4+od9o2eRBGbSS16H4xjTmmLV4q0r6JYIb5YTOVKs0IFJM EWqiqFDKTl0l8CgLGSh9kl9bJdbAI2ZdUu0znXzsAjkGqSAtK6atDAUdL4ugk8XVQnZ+uFoyJ9jMU Q3LiUIJjoPfa5iuI0tMG37J+H5g1Au176kL3ifn4orrnHWKpARCfZdyHGoniwy3+OMHBmWNw+dLnv cuJ04QRhGCS0SxSA13ER69ZjBFgb1sIeAKb+huvbwQNBY4sqpoeLS52a/2710XbQTPLayLjHE2rYU 3YAipeFg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uH802-0000000AXDL-3Auk; Mon, 19 May 2025 21:26:18 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uH7vo-0000000AVro-0itn for linux-arm-kernel@lists.infradead.org; Mon, 19 May 2025 21:21:58 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 727F25C3FDA; Mon, 19 May 2025 21:19:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4411CC4CEE4; Mon, 19 May 2025 21:21:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747689715; bh=AmLg2chyBTHsNhkZM74ucMywdT/YyQZpQrmFmE9oqEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YyVRm4WUiBVF5tPlidMg3ojEagyz5D95vxleZnTN/maonTbhtW0geSoj9TspF/+ar o2wJ9qSa9PS2q0LquvRKnrvIvTmystKaycBivtLwtVu/ym8M1bS5++qHBPdtdFps+p SDoHAhR+N+xx534ydIrcMew9AFG/r3TSu0cyybG0Pr7Xs5xn3sPu5WwsNYwEt0i/kW 2L00uOxw7NsEKIM8Bmg6iYaOmY068DsU+OjYFPHmF/0XbC1NzpQxrrWtK9LQIWuGfG G9qQg4wuKFQ+0KHHXmxsVc23WbHI/XqWOyn2yMM5SS1E3W6j7euC45K2myxsh86vo7 U4C/ERX8tyJHQ== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Alessandro Grassi , Mark Brown , Sasha Levin , mripard@kernel.org, wens@csie.org, linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 6.14 15/23] spi: spi-sun4i: fix early activation Date: Mon, 19 May 2025 17:21:22 -0400 Message-Id: <20250519212131.1985647-15-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250519212131.1985647-1-sashal@kernel.org> References: <20250519212131.1985647-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.14.7 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250519_142156_259916_5F40B12F X-CRM114-Status: GOOD ( 13.33 ) 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 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 fcbe864c9b7d6..4b070377e3d1d 100644 --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c @@ -264,6 +264,9 @@ static int sun4i_spi_transfer_one(struct spi_controller *host, 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 */ @@ -404,7 +407,7 @@ 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