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 X-Spam-Level: X-Spam-Status: No, score=-10.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 822D4C2BA1A for ; Tue, 7 Apr 2020 00:07:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 471E520768 for ; Tue, 7 Apr 2020 00:07:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586218057; bh=hFO4jLIKH+x5/7ssSNwRO2Wq0ZVgFPUvQpXBS26CSuE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ETCcC0HdqFhJzeAuTj/6nm/TJHCc7YqQO7s8Ol3LtN8cYHgaHQQuQsGoEIVKtfcVb kmnIRdP3n3PcX+b3nTo7ShoHJFzakkNwk3sxF06SgGTNpaoY53gkAhh6RaJzIN2TZU A9zN69aNky/iOPeLGBLGVWjVdT3Rkxov3yarj+4I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728020AbgDGAHg (ORCPT ); Mon, 6 Apr 2020 20:07:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:35596 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727600AbgDGABy (ORCPT ); Mon, 6 Apr 2020 20:01:54 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 837982082D; Tue, 7 Apr 2020 00:01:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586217714; bh=hFO4jLIKH+x5/7ssSNwRO2Wq0ZVgFPUvQpXBS26CSuE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u0zmHBIxN5rAfeOWb5duil8/9A0aRAHGd0hJ/I6iF5JGvf7ccixSnnElE2LKcP/O+ w9Akpkmg0XmgPnxFO3juMYjDYWQ8wrw9Pm23WKph28D8xZ55n+Mp7yIBSWDNg72vOn bLJC17I6srQR298pYxdAhsrnv+6v707BMi7dsPNk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ondrej Jirman , Chen-Yu Tsai , Maxime Ripard , Sasha Levin , linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 02/32] bus: sunxi-rsb: Return correct data when mixing 16-bit and 8-bit reads Date: Mon, 6 Apr 2020 20:01:20 -0400 Message-Id: <20200407000151.16768-2-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200407000151.16768-1-sashal@kernel.org> References: <20200407000151.16768-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ondrej Jirman [ Upstream commit a43ab30dcd4a1abcdd0d2461bf1cf7c0817f6cd3 ] 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 Signed-off-by: Maxime Ripard Signed-off-by: Sasha Levin --- drivers/bus/sunxi-rsb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c index be79d6c6a4e45..1bb00a959c67f 100644 --- a/drivers/bus/sunxi-rsb.c +++ b/drivers/bus/sunxi-rsb.c @@ -345,7 +345,7 @@ 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); -- 2.20.1