From patchwork Fri Feb 21 20:27:26 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: 11397333 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 51FCF138D for ; Fri, 21 Feb 2020 20:27:40 +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 2EDE62072C for ; Fri, 21 Feb 2020 20:27:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="OvbrlR75"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=megous.com header.i=@megous.com header.b="ABTKps/f" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2EDE62072C 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=uYx/bZmmwuG5TuoX4935x+pu92r+bdaMkePr/arcVoI=; b=OvbrlR75+t8UGc sPvdNR9SBxL6Yvd0iVsZWn9wbww5jHJHl8TrUtbF3WFWSVy8ZAzZihIujJJN9MSty5skoTZzg2ych hQFGxh6Z6+4T4Ui02JsQXuuFsDp7DP8EeIPzHn/ap8ZubOovvXcyjTgW/vRrhMmXZ9jouRks7SzMi fo6W96XNYs2nf78i+f92qFF0+zFxZvlnQBdaT9cDjixUHd99gcOdDorS2mlXfwEXM08Bm6lc0aDDV 5yk5mSXNSlDW2QQW9u9vor4ViJ4Ekt3bLZ+d+FOOwvrqxQ2IfrlVBwmP85Q17cqgxWu790XRrp2ue VqcDPtXe4imIXYgOX2dw==; 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 1j5Etf-0003lL-Jh; Fri, 21 Feb 2020 20:27:39 +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 1j5Etd-0003kY-2t for linux-arm-kernel@lists.infradead.org; Fri, 21 Feb 2020 20:27:39 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megous.com; s=mail; t=1582316852; bh=RT7hM71ofWAX5CWLAn+N0ibzSMqxRV062cMgGpFPdEY=; h=From:To:Cc:Subject:Date:From; b=ABTKps/fZEowbJ4P6ipUZh7IvHdAL18b1qHi7B9xvjA4dew8ntVZu250Lsyfvr7Um F3VIve3NlowLIq2TDPW1LS3K1cRKaNc/Enw9SsV0fHDml+4XAAWJfjNeZt5xx18L2b ElDeR1wr1KktD7WUMc+b3zv4HMZnPUzs6MIS5Z0s= From: Ondrej Jirman To: linux-sunxi@googlegroups.com Subject: [PATCH v2] bus: sunxi-rsb: Return correct data when mixing 16-bit and 8-bit reads Date: Fri, 21 Feb 2020 21:27:26 +0100 Message-Id: <20200221202728.1583768-1-megous@megous.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200221_122737_453640_E84F4EBB X-CRM114-Status: UNSURE ( 9.48 ) 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_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid 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 | 1 +- 1 file changed, 1 insertion(+), 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 @@ -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) & GENMASK(len * 8 - 1, 0); unlock: mutex_unlock(&rsb->lock);