From patchwork Tue Dec 8 12:28:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 340082 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 6AB1FC4167B for ; Tue, 8 Dec 2020 12:31:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36AA923AC0 for ; Tue, 8 Dec 2020 12:31:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726278AbgLHMbB (ORCPT ); Tue, 8 Dec 2020 07:31:01 -0500 Received: from fllv0015.ext.ti.com ([198.47.19.141]:45170 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727992AbgLHMbB (ORCPT ); Tue, 8 Dec 2020 07:31:01 -0500 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 0B8CTvvD066640; Tue, 8 Dec 2020 06:29:57 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1607430597; bh=XD/sefueOKoXyqgCh9BxBBpoHqtt4qwCxN2yjeUoZK4=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=RnZgNyPinWYkfuZjDZMZm8tgYth+cDBHPr7zePICNhiuUfeNe4F+NW17D9jlQ5WTR sdOGbpWAOOgPFIUptiO5rjGsZ4+rTCEo9XGV3yI9XS9Zr27murYwRHHqcuuttWfxGh K9k07GZYyAJR82vK7baJyA5FDeDL/TixkVo96clA= Received: from DLEE104.ent.ti.com (dlee104.ent.ti.com [157.170.170.34]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 0B8CTue4086386 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 8 Dec 2020 06:29:57 -0600 Received: from DLEE109.ent.ti.com (157.170.170.41) by DLEE104.ent.ti.com (157.170.170.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Tue, 8 Dec 2020 06:29:56 -0600 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE109.ent.ti.com (157.170.170.41) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Tue, 8 Dec 2020 06:29:56 -0600 Received: from deskari.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 0B8CTcjK095068; Tue, 8 Dec 2020 06:29:54 -0600 From: Tomi Valkeinen To: Sebastian Reichel , Laurent Pinchart , Nikhil Devshatwar , CC: , Sekhar Nori , Tony Lindgren , , Sam Ravnborg , Tomi Valkeinen Subject: [PATCH v5 06/29] drm/omap: dsi: send nop instead of page & column Date: Tue, 8 Dec 2020 14:28:32 +0200 Message-ID: <20201208122855.254819-7-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201208122855.254819-1-tomi.valkeinen@ti.com> References: <20201208122855.254819-1-tomi.valkeinen@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org The OMAP DSI command mode panel driver used to send page & column address before each frame update, and this code was moved into the DSI host driver when converting it to the DRM bridge model. However, it's not really required to send the page & column address before each frame. It's also something that doesn't really belong to the DSI host driver, so we should drop the code. That said, frame updates break if we don't send _something_ between the frames. A NOP command does the trick. It is not clear if this behavior is as expected from a DSI command mode frame transfer, or is it a feature/issue with OMAP DSI driver, or a feature/issue in the command mode panel used. Most likely this is related to the following from the DSI spec: "To enable PHY synchronization the host processor should periodically end HS transmission and drive the Data Lanes to the LP state. This transition should take place at least once per frame." Signed-off-by: Tomi Valkeinen Reviewed-by: Laurent Pinchart --- drivers/gpu/drm/omapdrm/dss/dsi.c | 46 ++++++++++++------------------- 1 file changed, 17 insertions(+), 29 deletions(-) diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c index 7fee9cf8782d..c6e044f8bece 100644 --- a/drivers/gpu/drm/omapdrm/dss/dsi.c +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c @@ -3884,35 +3884,19 @@ static int _dsi_update(struct dsi_data *dsi) return 0; } -static int _dsi_update_window(struct dsi_data *dsi, int channel, - int x, int y, int w, int h) -{ - int x1 = x, x2 = (x + w - 1); - int y1 = y, y2 = (y + h - 1); - u8 payloadX[5] = { MIPI_DCS_SET_COLUMN_ADDRESS, - x1 >> 8, x1 & 0xff, x2 >> 8, x2 & 0xff }; - u8 payloadY[5] = { MIPI_DCS_SET_PAGE_ADDRESS, - y1 >> 8, y1 & 0xff, y2 >> 8, y2 & 0xff }; - struct mipi_dsi_msg msgX = { 0 }, msgY = { 0 }; - int ret; +static int _dsi_send_nop(struct dsi_data *dsi, int channel) +{ + const u8 payload[] = { MIPI_DCS_NOP }; + const struct mipi_dsi_msg msg = { + .channel = channel, + .type = MIPI_DSI_DCS_SHORT_WRITE, + .tx_len = 1, + .tx_buf = payload, + }; WARN_ON(!dsi_bus_is_locked(dsi)); - msgX.type = MIPI_DSI_DCS_LONG_WRITE; - msgX.channel = channel; - msgX.tx_buf = payloadX; - msgX.tx_len = sizeof(payloadX); - - msgY.type = MIPI_DSI_DCS_LONG_WRITE; - msgY.channel = channel; - msgY.tx_buf = payloadY; - msgY.tx_len = sizeof(payloadY); - - ret = _omap_dsi_host_transfer(dsi, &msgX); - if (ret != 0) - return ret; - - return _omap_dsi_host_transfer(dsi, &msgY); + return _omap_dsi_host_transfer(dsi, &msg); } static int dsi_update_channel(struct omap_dss_device *dssdev, int channel) @@ -3944,10 +3928,14 @@ static int dsi_update_channel(struct omap_dss_device *dssdev, int channel) dsi_set_ulps_auto(dsi, false); - r = _dsi_update_window(dsi, channel, 0, 0, dsi->vm.hactive, - dsi->vm.vactive); + /* + * Send NOP between the frames. If we don't send something here, the + * updates stop working. This is probably related to DSI spec stating + * that the DSI host should transition to LP at least once per frame. + */ + r = _dsi_send_nop(dsi, channel); if (r < 0) { - DSSWARN("window update error: %d\n", r); + DSSWARN("failed to send nop between frames: %d\n", r); goto err; }