From patchwork Fri Mar 17 23:41:30 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Anholt X-Patchwork-Id: 9631737 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 3FE06602D6 for ; Fri, 17 Mar 2017 23:41:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 305B528518 for ; Fri, 17 Mar 2017 23:41:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 136F9285EF; Fri, 17 Mar 2017 23:41:38 +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 6F2A928518 for ; Fri, 17 Mar 2017 23:41:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B320C6E22E; Fri, 17 Mar 2017 23:41:35 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from anholt.net (anholt.net [50.246.234.109]) by gabe.freedesktop.org (Postfix) with ESMTP id 361DD6E22E for ; Fri, 17 Mar 2017 23:41:34 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by anholt.net (Postfix) with ESMTP id C7F4410A1E5C; Fri, 17 Mar 2017 16:41:33 -0700 (PDT) X-Virus-Scanned: Debian amavisd-new at anholt.net Received: from anholt.net ([127.0.0.1]) by localhost (kingsolver.anholt.net [127.0.0.1]) (amavisd-new, port 10024) with LMTP id gtaA3GKA6jh7; Fri, 17 Mar 2017 16:41:32 -0700 (PDT) Received: from eliezer.anholt.net (localhost [127.0.0.1]) by anholt.net (Postfix) with ESMTP id 55F4A10A1E55; Fri, 17 Mar 2017 16:41:32 -0700 (PDT) Received: by eliezer.anholt.net (Postfix, from userid 1000) id A8F872E9B51; Fri, 17 Mar 2017 16:41:31 -0700 (PDT) From: Eric Anholt To: dri-devel@lists.freedesktop.org Subject: [PATCH 1/2] drm/vc4: Fix DSI T_INIT timing. Date: Fri, 17 Mar 2017 16:41:30 -0700 Message-Id: <20170317234131.23621-1-eric@anholt.net> X-Mailer: git-send-email 2.11.0 Cc: linux-kernel@vger.kernel.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 DPHY spec requires a much larger T_INIT than I was specifying before. In the absence of clear specs from the slave of what their timing is, just use the value that the firmware was using. Signed-off-by: Eric Anholt --- drivers/gpu/drm/vc4/vc4_dsi.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index 160f981d1cf4..3bad8bad32a2 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -1094,7 +1094,17 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder) DSI_HS_DLT4_TRAIL) | VC4_SET_FIELD(0, DSI_HS_DLT4_ANLAT)); - DSI_PORT_WRITE(HS_DLT5, VC4_SET_FIELD(dsi_hs_timing(ui_ns, 1000, 5000), + /* T_INIT is how long STOP is driven after power-up to + * indicate to the slave (also coming out of power-up) that + * master init is complete, and should be greater than the + * maximum of two value: T_INIT,MASTER and T_INIT,SLAVE. The + * D-PHY spec gives a minimum 100us for T_INIT,MASTER and + * T_INIT,SLAVE, while allowing protocols on top of it to give + * greater minimums. The vc4 firmware uses an extremely + * conservative 5ms, and we maintain that here. + */ + DSI_PORT_WRITE(HS_DLT5, VC4_SET_FIELD(dsi_hs_timing(ui_ns, + 5 * 1000 * 1000, 0), DSI_HS_DLT5_INIT)); DSI_PORT_WRITE(HS_DLT6,