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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5022EEB56C for ; Fri, 8 Sep 2023 19:33:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229891AbjIHTdg (ORCPT ); Fri, 8 Sep 2023 15:33:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232487AbjIHTdU (ORCPT ); Fri, 8 Sep 2023 15:33:20 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDCAF2132; Fri, 8 Sep 2023 12:32:58 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24A19C43397; Fri, 8 Sep 2023 19:32:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694201529; bh=Ge+4fWFayUbITINuJLiw6XbxOHKzoUCdo4Ja6QrasUg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YyCC004oNi5VcPbauASoz4ZOrVHGxyd0aH+i7boLKCPRhIIYbDL+99/fmx3YIixB1 Nr5EYWvJE8lDkeYwzCzcHS1Ph34LSsciFx7i6pQSbQYNGuGpW4b7WO5uOOU0K4uq7m sdky45hcmpFeptZV4Yr8kUTiquA8MAXbsuPXOD7d58KKY7h7EkVmdLoXsIZWUg6Lr8 TeZo0AeWLLz8KKAeEJhCFqWMaxAsXFSwX506PQyEvXXHc9E5WksO32bFVY0dmpEXSP vS2dZAjdwYzx1aZ/+AYBkqa4a/sU8rYv5S0ysVSX+RMfq7TJD+JJ52pC0MdUNxWpYN qbHLoxiBsGLyg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Marek Vasut , Jagan Teki , Sasha Levin , inki.dae@samsung.com, m.szyprowski@samsung.com, andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org, airlied@gmail.com, daniel@ffwll.ch, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.4 03/31] drm: bridge: samsung-dsim: Drain command transfer FIFO before transfer Date: Fri, 8 Sep 2023 15:31:32 -0400 Message-Id: <20230908193201.3462957-3-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230908193201.3462957-1-sashal@kernel.org> References: <20230908193201.3462957-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.4.15 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marek Vasut [ Upstream commit 14806c6415820b1c4bc317655c40784d050a2edb ] Wait until the command transfer FIFO is empty before loading in the next command. The previous behavior where the code waited until command transfer FIFO was not full suffered from transfer corruption, where the last command in the FIFO could be overwritten in case the FIFO indicates not full, but also does not have enough space to store another transfer yet. Signed-off-by: Marek Vasut Reviewed-by: Jagan Teki Tested-by: Jagan Teki # imx8mm-icore Link: https://patchwork.freedesktop.org/patch/msgid/20230615201511.565923-1-marex@denx.de Signed-off-by: Sasha Levin --- drivers/gpu/drm/bridge/samsung-dsim.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c index 3194cabb26b32..891ec0245a910 100644 --- a/drivers/gpu/drm/bridge/samsung-dsim.c +++ b/drivers/gpu/drm/bridge/samsung-dsim.c @@ -932,7 +932,7 @@ static int samsung_dsim_wait_for_hdr_fifo(struct samsung_dsim *dsi) do { u32 reg = samsung_dsim_read(dsi, DSIM_FIFOCTRL_REG); - if (!(reg & DSIM_SFR_HEADER_FULL)) + if (reg & DSIM_SFR_HEADER_EMPTY) return 0; if (!cond_resched()) -- 2.40.1