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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 0EB44C433DF for ; Mon, 3 Aug 2020 12:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7A122054F for ; Mon, 3 Aug 2020 12:44:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596458657; bh=8dsC/cTUUWFMRDDnC5VWZkXw703a+7EhD/xyNN/90Ww=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=II5luawnoHwgrVhPaYlsJ3HCD/9qO7fFt/1dP5y92UiDlwqFDTO5LhGFIpsbpRhLa PjdvIawl9eX+KlmcWbTHaHNPqXrYeaKeoGjOCWARfMoft96LBhPm/dro6GSxfeHdy5 I/h7o6MRd85NuVQk34feI7zA003jUPp3eBjUf6pQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729553AbgHCMoQ (ORCPT ); Mon, 3 Aug 2020 08:44:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:54604 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728737AbgHCM20 (ORCPT ); Mon, 3 Aug 2020 08:28:26 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CE6E9207DF; Mon, 3 Aug 2020 12:28:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596457705; bh=8dsC/cTUUWFMRDDnC5VWZkXw703a+7EhD/xyNN/90Ww=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BH7PDv+AnkxRaQrxojDCMNI47PdvEyBmclEMkG674W3jo9uiBwZhLs1e+NFTdoptV /M2V5rk1HPD4zoABJ/ikHHApnIkLrmIsOW+QshEMkBcHdXAH71hzeq031geKKhgQiX V/epuJiAl0Vb51ZCeYYPN2b0nXlj7oye+hO4Db60= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Cercueil , Sam Ravnborg , =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= Subject: [PATCH 5.4 27/90] drm/dbi: Fix SPI Type 1 (9-bit) transfer Date: Mon, 3 Aug 2020 14:18:49 +0200 Message-Id: <20200803121858.938327468@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200803121857.546052424@linuxfoundation.org> References: <20200803121857.546052424@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul Cercueil commit 900ab59e2621053b009f707f80b2c19ce0af5dee upstream. The function mipi_dbi_spi1_transfer() will transfer its payload as 9-bit data, the 9th (MSB) bit being the data/command bit. In order to do that, it unpacks the 8-bit values into 16-bit values, then sets the 9th bit if the byte corresponds to data, clears it otherwise. The 7 MSB are padding. The array of now 16-bit values is then passed to the SPI core for transfer. This function was broken since its introduction, as the length of the SPI transfer was set to the payload size before its conversion, but the payload doubled in size due to the 8-bit -> 16-bit conversion. Fixes: 02dd95fe3169 ("drm/tinydrm: Add MIPI DBI support") Cc: # 5.4+ Signed-off-by: Paul Cercueil Reviewed-by: Sam Ravnborg Reviewed-by: Noralf Trønnes Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200703141341.1266263-1-paul@crapouillou.net Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_mipi_dbi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_mipi_dbi.c +++ b/drivers/gpu/drm/drm_mipi_dbi.c @@ -937,7 +937,7 @@ static int mipi_dbi_spi1_transfer(struct } } - tr.len = chunk; + tr.len = chunk * 2; len -= chunk; ret = spi_sync(spi, &m);