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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2D8BBC433DF for ; Wed, 12 Aug 2020 10:48:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0148E20781 for ; Wed, 12 Aug 2020 10:48:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="FLCDAVbv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727022AbgHLKsV (ORCPT ); Wed, 12 Aug 2020 06:48:21 -0400 Received: from fllv0015.ext.ti.com ([198.47.19.141]:38822 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726698AbgHLKsV (ORCPT ); Wed, 12 Aug 2020 06:48:21 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 07CAllRr030912; Wed, 12 Aug 2020 05:47:47 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1597229267; bh=evki6dI5ts5KOmGlF8qCX59wMWhwGQMc/ZNVJhMADKg=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=FLCDAVbve+oTVJhXUk7KB9Nf1N8Y5hv2YdvDJfrw1FlDnAjzXHCfuyeJByBhGI5VC IRk6YOcrYOzn50dLMDMAAUNtsDpxbJe1ntKJBfo4mxBorMFfFWdsFwycdn86j+IJ8L ZGVk/Vu1l5zcx7oB8QZkFkIBnkfHCFzIrC1ZStKw= Received: from DLEE114.ent.ti.com (dlee114.ent.ti.com [157.170.170.25]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 07CAll8W063305 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 12 Aug 2020 05:47:47 -0500 Received: from DLEE101.ent.ti.com (157.170.170.31) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Wed, 12 Aug 2020 05:47:47 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE101.ent.ti.com (157.170.170.31) 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; Wed, 12 Aug 2020 05:47:47 -0500 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 07CAlhX8025723; Wed, 12 Aug 2020 05:47:43 -0500 Subject: Re: [PATCH v8 0/3] drm: Add support for Cadence MHDP DPI/DP bridge and J721E wrapper. To: =?UTF-8?Q?Guido_G=c3=bcnther?= , Swapnil Jakhade CC: , , , , , , , , , , , , , , , , References: <1596713672-8146-1-git-send-email-sjakhade@cadence.com> <20200812083937.GA8816@bogon.m.sigxcpu.org> From: Tomi Valkeinen Message-ID: <3bcbbb0b-ee04-0f1e-6c54-97b01c552d82@ti.com> Date: Wed, 12 Aug 2020 13:47:42 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200812083937.GA8816@bogon.m.sigxcpu.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Guido, On 12/08/2020 11:39, Guido Günther wrote: > Hi, > On Thu, Aug 06, 2020 at 01:34:29PM +0200, Swapnil Jakhade wrote: >> This patch series adds new DRM bridge driver for Cadence MHDP DPI/DP >> bridge. The Cadence Display Port IP is also referred as MHDP (Mobile High >> Definition Link, High-Definition Multimedia Interface, Display Port). >> Cadence Display Port complies with VESA DisplayPort (DP) and embedded >> Display Port (eDP) standards. > > Is there any relation to the cadence mhdp ip core used inthe imx8mq: > > https://lore.kernel.org/dri-devel/cover.1590982881.git.Sandor.yu@nxp.com/ > > It looks very similar in several places so should that use the same driver? > Cheers, > -- Guido Interesting. So the original Cadence DP patches for TI SoCs did create a common driver with Rockchip's older mhdp driver. And looks like the IMX series points to an early version of that patch ("drm/rockchip: prepare common code for cdns and rk dpi/dp driver"). We gave up on that as the IPs did have differences and the firmwares used were apparently quite different. The end result was very difficult to maintain, especially as (afaik) none of the people involved had relevant Rockchip HW. The idea was to get a stable DP driver for TI SoCs ready and upstream, and then carefully try to create common parts with Rockchip's driver in small pieces. If the Rockchip and IMX mhdp have the same IP and same firmware, then they obviously should share code as done in the series you point to. Perhaps Cadence can clarify the differences between IMX, TI and Rockchip IPs and FWs? I'm worried that if there are IP differences, even if not great ones, and if the FWs are different and developed separately, it'll be a constant "fix X for SoC A, and accidentally break Y for SoC B and C", especially if too much code is shared. In the long run I'm all for a single driver (or large shared parts), but I'm not sure if we should start with that approach. Tomi -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki 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=-5.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 E3FC3C433E0 for ; Wed, 12 Aug 2020 10:48:04 +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 B46FB20781 for ; Wed, 12 Aug 2020 10:48:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ti.com header.i=@ti.com header.b="FLCDAVbv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B46FB20781 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=ti.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 268FF6E8D2; Wed, 12 Aug 2020 10:48:04 +0000 (UTC) Received: from fllv0015.ext.ti.com (fllv0015.ext.ti.com [198.47.19.141]) by gabe.freedesktop.org (Postfix) with ESMTPS id CB8F66E8D2 for ; Wed, 12 Aug 2020 10:48:02 +0000 (UTC) Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 07CAllRr030912; Wed, 12 Aug 2020 05:47:47 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1597229267; bh=evki6dI5ts5KOmGlF8qCX59wMWhwGQMc/ZNVJhMADKg=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=FLCDAVbve+oTVJhXUk7KB9Nf1N8Y5hv2YdvDJfrw1FlDnAjzXHCfuyeJByBhGI5VC IRk6YOcrYOzn50dLMDMAAUNtsDpxbJe1ntKJBfo4mxBorMFfFWdsFwycdn86j+IJ8L ZGVk/Vu1l5zcx7oB8QZkFkIBnkfHCFzIrC1ZStKw= Received: from DLEE114.ent.ti.com (dlee114.ent.ti.com [157.170.170.25]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 07CAll8W063305 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 12 Aug 2020 05:47:47 -0500 Received: from DLEE101.ent.ti.com (157.170.170.31) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Wed, 12 Aug 2020 05:47:47 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE101.ent.ti.com (157.170.170.31) 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; Wed, 12 Aug 2020 05:47:47 -0500 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 07CAlhX8025723; Wed, 12 Aug 2020 05:47:43 -0500 Subject: Re: [PATCH v8 0/3] drm: Add support for Cadence MHDP DPI/DP bridge and J721E wrapper. To: =?UTF-8?Q?Guido_G=c3=bcnther?= , Swapnil Jakhade References: <1596713672-8146-1-git-send-email-sjakhade@cadence.com> <20200812083937.GA8816@bogon.m.sigxcpu.org> From: Tomi Valkeinen Message-ID: <3bcbbb0b-ee04-0f1e-6c54-97b01c552d82@ti.com> Date: Wed, 12 Aug 2020 13:47:42 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200812083937.GA8816@bogon.m.sigxcpu.org> Content-Language: en-US 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: , Cc: devicetree@vger.kernel.org, jernej.skrabec@siol.net, praneeth@ti.com, yamonkar@cadence.com, narmstrong@baylibre.com, airlied@linux.ie, sandor.yu@nxp.com, jonas@kwiboo.se, nsekhar@ti.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, a.hajda@samsung.com, robh+dt@kernel.org, Laurent.pinchart@ideasonboard.com, jsarha@ti.com, mparab@cadence.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" SGkgR3VpZG8sCgpPbiAxMi8wOC8yMDIwIDExOjM5LCBHdWlkbyBHw7xudGhlciB3cm90ZToKPiBI aSwKPiBPbiBUaHUsIEF1ZyAwNiwgMjAyMCBhdCAwMTozNDoyOVBNICswMjAwLCBTd2FwbmlsIEph a2hhZGUgd3JvdGU6Cj4+IFRoaXMgcGF0Y2ggc2VyaWVzIGFkZHMgbmV3IERSTSBicmlkZ2UgZHJp dmVyIGZvciBDYWRlbmNlIE1IRFAgRFBJL0RQCj4+IGJyaWRnZS4gVGhlIENhZGVuY2UgRGlzcGxh eSBQb3J0IElQIGlzIGFsc28gcmVmZXJyZWQgYXMgTUhEUCAoTW9iaWxlIEhpZ2gKPj4gRGVmaW5p dGlvbiBMaW5rLCBIaWdoLURlZmluaXRpb24gTXVsdGltZWRpYSBJbnRlcmZhY2UsIERpc3BsYXkg UG9ydCkuCj4+IENhZGVuY2UgRGlzcGxheSBQb3J0IGNvbXBsaWVzIHdpdGggVkVTQSBEaXNwbGF5 UG9ydCAoRFApIGFuZCBlbWJlZGRlZAo+PiBEaXNwbGF5IFBvcnQgKGVEUCkgc3RhbmRhcmRzLgo+ IAo+IElzIHRoZXJlIGFueSByZWxhdGlvbiB0byB0aGUgY2FkZW5jZSBtaGRwIGlwIGNvcmUgdXNl ZCBpbnRoZSBpbXg4bXE6Cj4gCj4gICAgIGh0dHBzOi8vbG9yZS5rZXJuZWwub3JnL2RyaS1kZXZl bC9jb3Zlci4xNTkwOTgyODgxLmdpdC5TYW5kb3IueXVAbnhwLmNvbS8KPiAKPiBJdCBsb29rcyB2 ZXJ5IHNpbWlsYXIgaW4gc2V2ZXJhbCBwbGFjZXMgc28gc2hvdWxkIHRoYXQgdXNlIHRoZSBzYW1l IGRyaXZlcj8KPiBDaGVlcnMsCj4gIC0tIEd1aWRvCgpJbnRlcmVzdGluZy4KClNvIHRoZSBvcmln aW5hbCBDYWRlbmNlIERQIHBhdGNoZXMgZm9yIFRJIFNvQ3MgZGlkIGNyZWF0ZSBhIGNvbW1vbiBk cml2ZXIgd2l0aCBSb2NrY2hpcCdzIG9sZGVyIG1oZHAKZHJpdmVyLiBBbmQgbG9va3MgbGlrZSB0 aGUgSU1YIHNlcmllcyBwb2ludHMgdG8gYW4gZWFybHkgdmVyc2lvbiBvZiB0aGF0IHBhdGNoICgi ZHJtL3JvY2tjaGlwOgpwcmVwYXJlIGNvbW1vbiBjb2RlIGZvciBjZG5zIGFuZCByayBkcGkvZHAg ZHJpdmVyIikuCgpXZSBnYXZlIHVwIG9uIHRoYXQgYXMgdGhlIElQcyBkaWQgaGF2ZSBkaWZmZXJl bmNlcyBhbmQgdGhlIGZpcm13YXJlcyB1c2VkIHdlcmUgYXBwYXJlbnRseSBxdWl0ZQpkaWZmZXJl bnQuIFRoZSBlbmQgcmVzdWx0IHdhcyB2ZXJ5IGRpZmZpY3VsdCB0byBtYWludGFpbiwgZXNwZWNp YWxseSBhcyAoYWZhaWspIG5vbmUgb2YgdGhlIHBlb3BsZQppbnZvbHZlZCBoYWQgcmVsZXZhbnQg Um9ja2NoaXAgSFcuCgpUaGUgaWRlYSB3YXMgdG8gZ2V0IGEgc3RhYmxlIERQIGRyaXZlciBmb3Ig VEkgU29DcyByZWFkeSBhbmQgdXBzdHJlYW0sIGFuZCB0aGVuIGNhcmVmdWxseSB0cnkgdG8KY3Jl YXRlIGNvbW1vbiBwYXJ0cyB3aXRoIFJvY2tjaGlwJ3MgZHJpdmVyIGluIHNtYWxsIHBpZWNlcy4K CklmIHRoZSBSb2NrY2hpcCBhbmQgSU1YIG1oZHAgaGF2ZSB0aGUgc2FtZSBJUCBhbmQgc2FtZSBm aXJtd2FyZSwgdGhlbiB0aGV5IG9idmlvdXNseSBzaG91bGQgc2hhcmUKY29kZSBhcyBkb25lIGlu IHRoZSBzZXJpZXMgeW91IHBvaW50IHRvLgoKUGVyaGFwcyBDYWRlbmNlIGNhbiBjbGFyaWZ5IHRo ZSBkaWZmZXJlbmNlcyBiZXR3ZWVuIElNWCwgVEkgYW5kIFJvY2tjaGlwIElQcyBhbmQgRldzPwoK SSdtIHdvcnJpZWQgdGhhdCBpZiB0aGVyZSBhcmUgSVAgZGlmZmVyZW5jZXMsIGV2ZW4gaWYgbm90 IGdyZWF0IG9uZXMsIGFuZCBpZiB0aGUgRldzIGFyZSBkaWZmZXJlbnQKYW5kIGRldmVsb3BlZCBz ZXBhcmF0ZWx5LCBpdCdsbCBiZSBhIGNvbnN0YW50ICJmaXggWCBmb3IgU29DIEEsIGFuZCBhY2Np ZGVudGFsbHkgYnJlYWsgWSBmb3IgU29DIEIKYW5kIEMiLCBlc3BlY2lhbGx5IGlmIHRvbyBtdWNo IGNvZGUgaXMgc2hhcmVkLgoKSW4gdGhlIGxvbmcgcnVuIEknbSBhbGwgZm9yIGEgc2luZ2xlIGRy aXZlciAob3IgbGFyZ2Ugc2hhcmVkIHBhcnRzKSwgYnV0IEknbSBub3Qgc3VyZSBpZiB3ZSBzaG91 bGQKc3RhcnQgd2l0aCB0aGF0IGFwcHJvYWNoLgoKIFRvbWkKCi0tIApUZXhhcyBJbnN0cnVtZW50 cyBGaW5sYW5kIE95LCBQb3Jra2FsYW5rYXR1IDIyLCAwMDE4MCBIZWxzaW5raS4KWS10dW5udXMv QnVzaW5lc3MgSUQ6IDA2MTU1MjEtNC4gS290aXBhaWtrYS9Eb21pY2lsZTogSGVsc2lua2kKX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVsIG1h aWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMu ZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg==