From patchwork Sat Oct 14 04:02:50 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen-Yu Tsai X-Patchwork-Id: 10006187 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 532166037E for ; Sat, 14 Oct 2017 04:03:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4811329188 for ; Sat, 14 Oct 2017 04:03:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3CF5B291AB; Sat, 14 Oct 2017 04:03:28 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED 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 C203B29188 for ; Sat, 14 Oct 2017 04:03:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3925C6EC46; Sat, 14 Oct 2017 04:03:13 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from wens.csie.org (mirror2.csie.ntu.edu.tw [140.112.30.76]) by gabe.freedesktop.org (Postfix) with ESMTPS id A96CE6EC21 for ; Sat, 14 Oct 2017 04:03:11 +0000 (UTC) Received: by wens.csie.org (Postfix, from userid 1000) id D0461600F7; Sat, 14 Oct 2017 12:02:57 +0800 (CST) From: Chen-Yu Tsai To: Maxime Ripard , David Airlie Subject: [PATCH 5/7] drm/sun4i: backend: Offset layer buffer address by DRAM starting address Date: Sat, 14 Oct 2017 12:02:50 +0800 Message-Id: <20171014040252.9621-6-wens@csie.org> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171014040252.9621-1-wens@csie.org> References: <20171014040252.9621-1-wens@csie.org> Cc: Chen-Yu Tsai , linux-sunxi@googlegroups.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.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 The display backend, as well as other peripherals that have a DRAM clock gate and access DRAM directly, bypassing the system bus, address the DRAM starting from 0x0, while physical addresses the system uses starts from 0x40000000 (or 0x20000000 in A80's case). Correct the address configured into the backend layer registers by PHYS_OFFSET to account for this. Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support") Signed-off-by: Chen-Yu Tsai --- drivers/gpu/drm/sun4i/sun4i_backend.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c index 4fefd8add714..d18d7e88d511 100644 --- a/drivers/gpu/drm/sun4i/sun4i_backend.c +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c @@ -216,6 +216,13 @@ int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend, paddr = drm_fb_cma_get_gem_addr(fb, state, 0); DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr); + /* + * backend DMA accesses DRAM directly, bypassing the system + * bus. As such, the address range is different and the buffer + * address needs to be corrected. + */ + paddr -= PHYS_OFFSET; + /* Write the 32 lower bits of the address (in bits) */ lo_paddr = paddr << 3; DRM_DEBUG_DRIVER("Setting address lower bits to 0x%x\n", lo_paddr);