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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 4F16FC64E8A for ; Mon, 30 Nov 2020 09:46:29 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 9D821206B6 for ; Mon, 30 Nov 2020 09:46:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="BiQ8jnkh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D821206B6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DA5666E43C; Mon, 30 Nov 2020 09:46:27 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id AE0BA6E43C for ; Mon, 30 Nov 2020 09:46:26 +0000 (UTC) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 2F2CA538; Mon, 30 Nov 2020 10:46:25 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1606729585; bh=iWSpmOaRT8F5jWtp2Vpx9N0hysxNESH6Ll8Ha77TGpw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BiQ8jnkhSU5qplMMA/CX/6vg/ImWQCVrZ0YyYviMSJrIJZhVLlkT8NeAzGNg/NmxP l3+2YtCDQpgGhwUcT8WFAlVHjw08+K5QCzUHWVPkZ6zNscl+GQe1p1qf+auOL8ucNg HlLLddK4IZ+CdKJ62LEtJVFyRtcMdTJMjtxhgZks= Date: Mon, 30 Nov 2020 11:46:17 +0200 From: Laurent Pinchart To: Nikhil Devshatwar Subject: Re: [PATCH v3 4/6] drm/tidss: Set bus_format correctly from bridge/connector Message-ID: <20201130094617.GE4141@pendragon.ideasonboard.com> References: <20201119160134.9244-1-nikhil.nd@ti.com> <20201119160134.9244-5-nikhil.nd@ti.com> <20201130063503.phivehin7l2cx53j@NiksLab> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201130063503.phivehin7l2cx53j@NiksLab> 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: , Cc: Tomi Valkeinen , Sekhar Nori , Yuti Amonkar , dri-devel@lists.freedesktop.org, Swapnil Jakhade Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Nikhil, On Mon, Nov 30, 2020 at 12:05:03PM +0530, Nikhil Devshatwar wrote: > On 14:51-20201125, Tomi Valkeinen wrote: > > On 19/11/2020 18:01, Nikhil Devshatwar wrote: > > > Remove the old code to iterate over the bridge chain, as this is > > > already done by the framework. > > > The bridge state should have the negotiated bus format and flags. > > > Use these from the bridge's state. > > > If the bridge does not support format negotiation, error out > > > and fail. > > > > > > Signed-off-by: Nikhil Devshatwar > > > Reviewed-by: Tomi Valkeinen > > > --- > > > > > > Notes: > > > changes from v2: > > > * Remove the old code and use the flags from the bridge state > > > > > > drivers/gpu/drm/tidss/tidss_encoder.c | 36 +++++++++++---------------- > > > 1 file changed, 14 insertions(+), 22 deletions(-) > > > > If a first bridge (after the crtc) supports two bus formats as input, how does tidss choose between > > those? This patch just picks bstate->input_bus_cfg.format, and it's not clear to me which one that > > is (the first one?). Also, we don't check if tidss actually supports the bus format. > > The selection is done by the framework in > select_bus_fmt_recursive at drivers/gpu/drm/drm_bridge.c:810 > > My understanding is that currently, the format negotiation logic does > not negotiate all the way till encoder, it stops only at the > first_bridge. Should we then implement a bridge in the tidss driver to model the internal encoder, in order to support format negotiation all the way to the tidss ? -- Regards, Laurent Pinchart _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel