From patchwork Wed Feb 19 01:09:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Ond=C5=99ej_Jirman?= X-Patchwork-Id: 11390175 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DB76D92A for ; Wed, 19 Feb 2020 01:10:14 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id B4FC52465D for ; Wed, 19 Feb 2020 01:10:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ImDxGlMS"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=megous.com header.i=@megous.com header.b="QHSn0XjA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4FC52465D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=megous.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=ymy/MZLe3VB7fu+EM142hxmInswT+Kkf4Mb5BWvrd5o=; b=ImDxGlMSrSWbFY 5tC/4Tp4CYFTKTJhfMjThMN4roUJFNFMCbJj7pgt8Vf8fivhoN0EnWFYjATtCdiEF0JiJVnIYHlDa yPcyrUIzzEaOTgwnIk+vCue+Nt7lP2kqB2UnBhqPTslpQzgbhOQwSC4xQbXTpKtzukDT6eF3kby/8 Rn8+ARc3Q6/D1wNIyupKUYGfpRCsQDha2OUrtIvRvLQF+PmyRCyVC6r2f9RAK1ES9Sw019VWeS6Vq rqMPiGnp49itQrdsWjhbQptniyW+7JVc/HhoNNIop8O0sPh5fJ13aAMIZxR1NXCTouSFu3zOO3OWa 33u4ZpjFb+A/D1PJnRCg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j4DsN-0008En-TO; Wed, 19 Feb 2020 01:10:07 +0000 Received: from vps.xff.cz ([195.181.215.36]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j4DsK-0007Ze-66 for linux-arm-kernel@lists.infradead.org; Wed, 19 Feb 2020 01:10:06 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megous.com; s=mail; t=1582074599; bh=Aeuv5iYbaAp7rr6i5ZST/n1JdcOfY/hR+2BNrgy8C+E=; h=From:To:Cc:Subject:Date:From; b=QHSn0XjACs3lffkvnSFb2Pb78S1/c0rmc4BVbXsaxeakyWxv3Mh/uhDOckugdgAqZ FcC8PID+c6c6kZWMrj4KvwtCzGJHnr4igAaFwpP17DnZYrxwk+t60tjSDIqWrlF0aD UjWgeF7tQbJzZPcmQflTg7yTojktxGRiFa4KFSkY= From: Ondrej Jirman To: linux-sunxi@googlegroups.com Subject: [PATCH] bus: sunxi-rsb: Return correct data when mixing 16-bit and 8-bit reads Date: Wed, 19 Feb 2020 02:09:50 +0100 Message-Id: <20200219010951.395599-1-megous@megous.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200218_171004_565100_B1AB652E X-CRM114-Status: UNSURE ( 9.82 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ondrej Jirman , Samuel Holland , open list , Maxime Ripard , Stephen Boyd , Chen-Yu Tsai , "moderated list:ARM/Allwinner sunXi SoC support" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org When doing a 16-bit read that returns data in the MSB byte, the RSB_DATA register will keep the MSB byte unchanged when doing the following 8-bit read. sunxi_rsb_read() will then return a result that contains high byte from 16-bit read mixed with the 8-bit result. The consequence is that after this happens the PMIC's regmap will look like this: (0x33 is the high byte from the 16-bit read) % cat /sys/kernel/debug/regmap/sunxi-rsb-3a3/registers 00: 33 01: 33 02: 33 03: 33 04: 33 05: 33 06: 33 07: 33 08: 33 09: 33 0a: 33 0b: 33 0c: 33 0d: 33 0e: 33 [snip] Fix this by masking the result of the read with the correct mask based on the size of the read. There are no 16-bit users in the mainline kernel, so this doesn't need to get into the stable tree. Signed-off-by: Ondrej Jirman Acked-by: Chen-Yu Tsai --- drivers/bus/sunxi-rsb.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c index b8043b58568ac..8ab6a3865f569 100644 --- a/drivers/bus/sunxi-rsb.c +++ b/drivers/bus/sunxi-rsb.c @@ -316,6 +316,7 @@ static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr, { u32 cmd; int ret; + u32 mask; if (!buf) return -EINVAL; @@ -323,12 +324,15 @@ static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr, switch (len) { case 1: cmd = RSB_CMD_RD8; + mask = 0xffu; break; case 2: cmd = RSB_CMD_RD16; + mask = 0xffffu; break; case 4: cmd = RSB_CMD_RD32; + mask = 0xffffffffu; break; default: dev_err(rsb->dev, "Invalid access width: %zd\n", len); @@ -345,7 +349,7 @@ static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr, if (ret) goto unlock; - *buf = readl(rsb->regs + RSB_DATA); + *buf = readl(rsb->regs + RSB_DATA) & mask; unlock: mutex_unlock(&rsb->lock);