From patchwork Sat Jan 21 16:31:13 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Keeping X-Patchwork-Id: 9530393 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A079A6020B for ; Sat, 21 Jan 2017 16:33:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 913B028119 for ; Sat, 21 Jan 2017 16:33:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 833222842E; Sat, 21 Jan 2017 16:33:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.6 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,RCVD_IN_SORBS_SPAM,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 202AD28119 for ; Sat, 21 Jan 2017 16:33:30 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2B3786E2C6; Sat, 21 Jan 2017 16:32:27 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from metanate.com (dougal.metanate.com [90.155.101.14]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5F7376E289 for ; Sat, 21 Jan 2017 16:32:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=simple/simple; d=metanate.com; s=stronger; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=fKLmZ5U/WoMrHxBT0iweAqaF7p64PU+rQPy7M9HAmJ0=; b=IFCm8OVLjJpphaHz73rF9Xi11CI17VQcyDY3SPh2peflzMwAf9ZzLqKEsecm6XPi5dD77Yi7i7ls/3WMZ2GQ1qrgfXHsWQHK1bNsqVicdxFhoTin9x20lRaBKQqO031wB4PFv5dxPmzMso1HwaLrbD/wGyTVseFJduROFNP/Hu6BAk8pt2a1wUlSZaiqczvQksEfRzxMoSJPSc0jPf4CGSD/tC0JbqHWgUG1spBdRpCnXYvSnRYKqUwl/MkRV+zdMZnJ/0UiwKKbvRtF7tGMvgge5yDpyXSS9bzYdk2X3jB9VXOvq33KUacal4NeAFw++74YotB/mlyPkPUOSM9JQA==; Received: from johnkeeping.plus.com ([81.174.171.191] helo=localhost.localdomain) by shrek.metanate.com with esmtpsa (TLSv1.2:DHE-RSA-AES128-GCM-SHA256:128) (Exim 4.83_RC2) (envelope-from ) id 1cUya0-0004rJ-DX; Sat, 21 Jan 2017 16:31:52 +0000 From: John Keeping To: Mark Yao Subject: [PATCH v2 11/26] drm/rockchip: dw-mipi-dsi: don't assume buffer is aligned Date: Sat, 21 Jan 2017 16:31:13 +0000 Message-Id: <20170121163128.22240-12-john@metanate.com> X-Mailer: git-send-email 2.11.0.197.gb556de5.dirty In-Reply-To: <20170121163128.22240-1-john@metanate.com> References: <20170121163128.22240-1-john@metanate.com> Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, Chris Zhong , linux-arm-kernel@lists.infradead.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP By dereferencing the MIPI command buffer as a u32* we rely on it being correctly aligned on ARM, but this may not be the case. Copy it into a stack variable that will be correctly aligned. Signed-off-by: John Keeping Reviewed-by: Chris Zhong --- Unchanged in v2 --- drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c index 03fc096fe1bd..ddbc037e7ced 100644 --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c @@ -607,10 +607,10 @@ static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi, static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi, const struct mipi_dsi_msg *msg) { - const u32 *tx_buf = msg->tx_buf; - int len = msg->tx_len, pld_data_bytes = sizeof(*tx_buf), ret; + const u8 *tx_buf = msg->tx_buf; + int len = msg->tx_len, pld_data_bytes = sizeof(u32), ret; u32 hdr_val = GEN_HDATA(msg->tx_len) | GEN_HTYPE(msg->type); - u32 remainder = 0; + u32 remainder; u32 val; if (msg->tx_len < 3) { @@ -621,12 +621,14 @@ static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi, while (DIV_ROUND_UP(len, pld_data_bytes)) { if (len < pld_data_bytes) { + remainder = 0; memcpy(&remainder, tx_buf, len); dsi_write(dsi, DSI_GEN_PLD_DATA, remainder); len = 0; } else { - dsi_write(dsi, DSI_GEN_PLD_DATA, *tx_buf); - tx_buf++; + memcpy(&remainder, tx_buf, pld_data_bytes); + dsi_write(dsi, DSI_GEN_PLD_DATA, remainder); + tx_buf += pld_data_bytes; len -= pld_data_bytes; }