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 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 C93BEC87FC5 for ; Wed, 23 Jul 2025 10:05:57 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8817D10E78E; Wed, 23 Jul 2025 10:05:56 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="RX1xMwKK"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4F82210E791 for ; Wed, 23 Jul 2025 10:05:45 +0000 (UTC) Received: from [127.0.1.1] (91-158-153-178.elisa-laajakaista.fi [91.158.153.178]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 0B9DC1129; Wed, 23 Jul 2025 12:05:05 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1753265106; bh=+PxAbR0AgAh+6ttH91klZ+Aji+1hZOcFtaS/g/i1Q0s=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=RX1xMwKKPpK5WRz44L6QlrkdK2tshCe6rta1BfyesxjjiAK0rd9qw1n2zx9AchHFD LHhbk6hlcYg7cvduzEblm0OUQbdlCr0AihRY2/Ht95rNkjLRONyW8AU0hkuLE8KWj8 0D5Wk6GAGxQ4QZQ2cDeGVfnEfdAIRN8jIMLqsmPo= From: Tomi Valkeinen Date: Wed, 23 Jul 2025 13:05:12 +0300 Subject: [PATCH v5 06/15] drm/bridge: cdns-dsi: Remove broken fifo emptying check MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250723-cdns-dsi-impro-v5-6-e61cc06074c2@ideasonboard.com> References: <20250723-cdns-dsi-impro-v5-0-e61cc06074c2@ideasonboard.com> In-Reply-To: <20250723-cdns-dsi-impro-v5-0-e61cc06074c2@ideasonboard.com> To: Jyri Sarha , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Vinod Koul , Kishon Vijay Abraham I , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Jayesh Choudhary , Dmitry Baryshkov Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-phy@lists.infradead.org, Francesco Dolcini , Aradhya Bhatia , Devarsh Thakkar , Parth Pancholi , Tomi Valkeinen X-Mailer: b4 0.15-dev-c25d1 X-Developer-Signature: v=1; a=openpgp-sha256; l=2010; i=tomi.valkeinen@ideasonboard.com; h=from:subject:message-id; bh=+PxAbR0AgAh+6ttH91klZ+Aji+1hZOcFtaS/g/i1Q0s=; b=owEBbQKS/ZANAwAIAfo9qoy8lh71AcsmYgBogLPrTWKpTI7qlDcFlmzpTrNDGKKo18w9aaIO6 KxFKD5lOS2JAjMEAAEIAB0WIQTEOAw+ll79gQef86f6PaqMvJYe9QUCaICz6wAKCRD6PaqMvJYe 9RRAEACdS40ggRn6TNhjMQt8B5FDvfYJ1X91p5qVBMm853Zy5ZJ1LS1L1M5deJpBeBU2XjGHmvg LGNeNqz/gVeVlGh9Ab8GClyFgcziAl3nWfBRdGXG70Um/OWZjdn8bJRFodJJIGxkjmmWWwwKbtL tTFlVefMDKvHDwCvgVAHG1Rxdtp8bn1L1irWH2x9SmQbmHbLnLkEyL638VGcT+1Aj2jjboVDqE9 ETLyfK5Pe6gRACRz0y7HWsCPIsMDSRxRCZmkDgiBjmCXktMVxul1Dad+V5CmPKZZ4tP4HowXBRV DbZmE1/OrGc4TagxxfrSEPoGh2EFdOMZTaut7xebklIf77rDmJoVSd6l14vLPimsrCy/4QuntH+ iurDqd5h4jAYLJxaW45Bfj2OZvgXGz3vZkbTRxKA+5j0nPnTLGL6XkTnWD/JraXau+K2hcTpkie qoohrmuXfF81+pPSnekpHeL5AmwGIntKlZaqdiphdTFwC26MAxG+NJm94vNOjEbNhJ4rwXUDZqU p2DOiocvo2yADK8cHXVYm0g5zIX5PdnkK3lSbcgr2Lvz5JgQ3xsZZxmlclCg5RRaWpxTVQA/Pwm LF5pYJ7NUvy/ZhLLKhqp/d5M9fXRonuX84oBWrZ77TD6b5rGa9Icr57aKutAqZwsFbwTvZQ47D7 eA5Izv94iKfXodw== X-Developer-Key: i=tomi.valkeinen@ideasonboard.com; a=openpgp; fpr=C4380C3E965EFD81079FF3A7FA3DAA8CBC961EF5 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" The driver checks if "DPI(HFP) > DSI(HSS+HSA+HSE+HBP)", and rejects the mode if not. However, testing shows that this doesn't hold at all. I can set the hfp to very small values, with no errors. The feedback from the HW team also was that the check is not right, although it's not clear if there's a way to validate the FIFO emptying. The check rejects quite a lot of modes, apparently for no good reason, so drop the check. Tested-by: Parth Pancholi Tested-by: Jayesh Choudhary Reviewed-by: Devarsh Thakkar Signed-off-by: Tomi Valkeinen --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 15 --------------- 1 file changed, 15 deletions(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index eae9469ef431..000c5a2367fe 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -553,7 +553,6 @@ static int cdns_dsi_check_conf(struct cdns_dsi *dsi, { struct cdns_dsi_output *output = &dsi->output; struct phy_configure_opts_mipi_dphy *phy_cfg = &output->phy_opts.mipi_dphy; - unsigned long dsi_hss_hsa_hse_hbp; unsigned int nlanes = output->dev->lanes; int ret; @@ -575,20 +574,6 @@ static int cdns_dsi_check_conf(struct cdns_dsi *dsi, if (ret) return ret; - dsi_hss_hsa_hse_hbp = dsi_cfg->hbp + DSI_HBP_FRAME_OVERHEAD; - if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) - dsi_hss_hsa_hse_hbp += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD; - - /* - * Make sure DPI(HFP) > DSI(HSS+HSA+HSE+HBP) to guarantee that the FIFO - * is empty before we start a receiving a new line on the DPI - * interface. - */ - if ((u64)phy_cfg->hs_clk_rate * - (mode->hsync_start - mode->hdisplay) * nlanes < - (u64)dsi_hss_hsa_hse_hbp * mode->clock * 1000) - return -EINVAL; - return 0; } -- 2.43.0