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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3629C433EF for ; Wed, 6 Apr 2022 16:55:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238049AbiDFQ5U (ORCPT ); Wed, 6 Apr 2022 12:57:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238064AbiDFQ5A (ORCPT ); Wed, 6 Apr 2022 12:57:00 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4496B18DAAE for ; Wed, 6 Apr 2022 07:54:33 -0700 (PDT) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nc739-0000f6-NQ; Wed, 06 Apr 2022 16:54:23 +0200 Received: from sha by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1nc737-0006AJ-9q; Wed, 06 Apr 2022 16:54:21 +0200 Date: Wed, 6 Apr 2022 16:54:21 +0200 From: Sascha Hauer To: Andy Yan Cc: Piotr Oniszczuk , dri-devel@lists.freedesktop.org, "linux-arm-kernel@lists.infradead.org" , "open list:ARM/Rockchip SoC..." , "devicetree@vger.kernel.org" , kernel@pengutronix.de, Benjamin Gaignard , Michael Riesch , Sandy Huang , Heiko =?iso-8859-15?Q?St=FCbner?= , Peter Geis , Kever Yang Subject: Re: [PATCH v9 00/23] drm/rockchip: RK356x VOP2 support Message-ID: <20220406145421.GW4012@pengutronix.de> References: <20220328151116.2034635-1-s.hauer@pengutronix.de> <20220401125205.GL4012@pengutronix.de> <1c0fbf4f-2e17-29f9-5c69-c80b53ff3d2f@rock-chips.com> <20220405093700.GQ4012@pengutronix.de> <12a8c0ef-90ee-cf7e-50a0-e00add8af147@rock-chips.com> <20220406081333.GU4012@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 16:05:52 up 7 days, 2:35, 73 users, load average: 0.24, 0.24, 0.22 User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: devicetree@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Wed, Apr 06, 2022 at 04:36:42PM +0800, Andy Yan wrote: > Hi: > > On 4/6/22 16:13, Sascha Hauer wrote: > > On Wed, Apr 06, 2022 at 10:02:59AM +0800, Andy Yan wrote: > > > Hi: > > > > > > On 4/5/22 17:37, Sascha Hauer wrote: > > > > On Sat, Apr 02, 2022 at 09:37:17AM +0800, Andy Yan wrote: > > > > > Hi Sacha: > > > > > > > > > > On 4/1/22 20:52, Sascha Hauer wrote: > > > > > > -- > > > > > > >From cbc03073623a7180243331ac24c3afaf9dec7522 Mon Sep 17 00:00:00 2001 > > > > > > From: Sascha Hauer > > > > > > Date: Fri, 1 Apr 2022 14:48:49 +0200 > > > > > > Subject: [PATCH] fixup! drm: rockchip: Add VOP2 driver > > > > > > > > > > > > --- > > > > > > drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 14 ++++++++++++++ > > > > > > 1 file changed, 14 insertions(+) > > > > > > > > > > > > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c > > > > > > index 7dba7b9b63dc6..1421bf2f133f1 100644 > > > > > > --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c > > > > > > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c > > > > > > @@ -2287,6 +2287,20 @@ static int vop2_create_crtc(struct vop2 *vop2) > > > > > > } > > > > > > } > > > > > > + if (vop2->data->soc_id == 3566) { > > > > > > + /* > > > > > > + * On RK3566 these windows don't have an independent > > > > > > + * framebuffer. They share the framebuffer with smart0, > > > > > > + * esmart0 and cluster0 respectively. > > > > > > + */ > > > > > > + switch (win->data->phys_id) { > > > > > > + case ROCKCHIP_VOP2_SMART1: > > > > > > + case ROCKCHIP_VOP2_ESMART1: > > > > > > + case ROCKCHIP_VOP2_CLUSTER1: > > > > > > + continue; > > > > > > + } > > > > > Think about this , there maybe other upcoming vop2 base soc, they may only > > > > > have > > > > > > > > > > mirror window Smart1 Esmart1, or Smart1, Esmart1, Esmart2, Cluster1. > > > > > > > > > > I think this should add WIN_FEATURE at the platform description file > > > > > rockchip_vop2_reg.c, then > > > > > > > > > > check the FEATURE to decide whether the driver should give this window a > > > > > special treatment. > > > > > > > > > > this can make one code run for different soc with different platform > > > > > description. or we should add > > > > > > > > > > the same code logic for different soc again and again. > > > > You mean like done in the downstream Kernel? Here indeed we have a > > > > WIN_FEATURE_MIRROR flag added to the platform description. This is then > > > > evaluated with: > > > > > > > > static bool vop2_is_mirror_win(struct vop2_win *win) > > > > { > > > > return soc_is_rk3566() && (win->feature & WIN_FEATURE_MIRROR); > > > > } > > > > > > > > So a flag is added and afterwards its evaluation is SoC specific. That > > > > doesn't help at all and only obfuscates things. > > > > > > > > Besides, experience shows that you can't predict a good abstraction for > > > This is not a  predict,  this is an IP feature, so it will appeared on > > > upcoming SOC. > > > > > > We have rk3588 with 8 windows(4 Cluster + 4 Esmart, no Smart window), and > > > > > > also have a entry level soc which only have 4 windows, they both have this > > > feature. > > Same as with the other discussion: Please let's solve this once we are > > there. > > > I am not sure if this is the suitable way for upstream, this sound like > > just solve the issue appeared at the front of eyes and not think any > > thing about make this driver easy to support new hardware in the future. Oh come on, we are not talking about any major design decisions here, this is merely a small implementation detail that can be refactored anytime. I would change it when all it takes is to add a feature (or better: nonfeature) flag to the window data, but the combination of the flag *and* testing on which SoC the flag shall be honoured makes me feel that the feature flag is still not the best abstraction. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |