From patchwork Thu May 30 09:36:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aradhya Bhatia X-Patchwork-Id: 13680059 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B0892C25B7E for ; Thu, 30 May 2024 09:37:33 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B422611B54E; Thu, 30 May 2024 09:37:32 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=ti.com header.i=@ti.com header.b="ZkKKcUrY"; dkim-atps=neutral Received: from fllv0016.ext.ti.com (fllv0016.ext.ti.com [198.47.19.142]) by gabe.freedesktop.org (Postfix) with ESMTPS id E08EB11B1B3 for ; Thu, 30 May 2024 09:36:52 +0000 (UTC) Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 44U9aXEf030983; Thu, 30 May 2024 04:36:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1717061793; bh=1KYYm54tymbTNJp06YFH1DJi8RZj+jpPyPwKIKxm3dU=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=ZkKKcUrYwzoDEBJwh6aF1ZM+Nz48NfAzRfxRsup6fndN9i4JRQQz+2e0llKrvsS3i jmpby4fHjGTm6XzGW7nS47kz9A+r8d5Cb6QPqWvVBz09h3aOq5o5U+J/4HqUhX5Luu r4L43K3zVbZ7M/kiIBlaeXVLd7x9uzN2PoM//Yns= Received: from DFLE112.ent.ti.com (dfle112.ent.ti.com [10.64.6.33]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 44U9aXl8104060 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 30 May 2024 04:36:33 -0500 Received: from DFLE102.ent.ti.com (10.64.6.23) by DFLE112.ent.ti.com (10.64.6.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Thu, 30 May 2024 04:36:33 -0500 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DFLE102.ent.ti.com (10.64.6.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Thu, 30 May 2024 04:36:33 -0500 Received: from localhost (uda0496377.dhcp.ti.com [172.24.227.31]) by lelvsmtp6.itg.ti.com (8.15.2/8.15.2) with ESMTP id 44U9aWk2086397; Thu, 30 May 2024 04:36:32 -0500 From: Aradhya Bhatia To: Tomi Valkeinen , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Jyri Sarha , Thomas Zimmermann , David Airlie , Daniel Vetter CC: DRI Development List , Linux Kernel List , Sam Ravnborg , Thierry Reding , Kieran Bingham , Nishanth Menon , Vignesh Raghavendra , Praneeth Bajjuri , Udit Kumar , Devarsh Thakkar , Jayesh Choudhary , Jai Luthra , Aradhya Bhatia Subject: [PATCH v2 6/9] drm/bridge: cdns-dsi: Reset the DCS write FIFO Date: Thu, 30 May 2024 15:06:18 +0530 Message-ID: <20240530093621.1925863-7-a-bhatia1@ti.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240530093621.1925863-1-a-bhatia1@ti.com> References: <20240530093621.1925863-1-a-bhatia1@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Allow the DCS Write FIFO in the cdns-dsi controller to reset before any DCS packet is transmitted to the DSI sink device. The DCS FIFO reset is optional. Not all panels require it. But at least one of the DSI based panel that uses Ilitek ILI9881C (DSI to DPI bridge) doesn't work with without this reset. Signed-off-by: Aradhya Bhatia --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 05d2f4cc50da..87fdd07ca0bc 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -1037,6 +1037,9 @@ static ssize_t cdns_dsi_transfer(struct mipi_dsi_host *host, cdns_dsi_init_link(dsi); + /* Reset the DCS Write FIFO */ + writel(0x00, dsi->regs + DIRECT_CMD_FIFO_RST); + ret = mipi_dsi_create_packet(&packet, msg); if (ret) goto out;