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 9A217C433F5 for ; Wed, 2 Feb 2022 13:15:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 96B9610E338; Wed, 2 Feb 2022 13:15:15 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id AB24E10E161; Wed, 2 Feb 2022 13:15:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643807714; x=1675343714; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=7ImU0bFQQR2LlCRItDZiSaLjRE9eYfLv0W/Kf15V6Q0=; b=cjHS+Z0OSE8jDoaaNBOvFtPVmU9phSMImATz8XC4THjuXpaE/FQsgj2w 6YP6RFQ1DVt+xfG6MFhSDHX+gLK++PQCJ1zttzc39i09gG5jfY9hEJp5I S8FIh2vuFyM7u9UHK8uAaOR6ZpozWaCAt3xsTx9UN9ESXimXw1RFfzpaV I0IQIUTK3bI0U6sDrqgcjg50VsFLJlX/tN8NBwBqhUF20FbTqwJz6YPqW NdxSrrUF9u0JTi6mM/VHn1WPt2mzUvT5/DwoEcFglgul1UAQGqsDNFcGa 4AQdmWjVh9nFjhj4dYw3PjStjGX8pGL/3lxU6KwPj9GjtwidYzPkH8HDB w==; X-IronPort-AV: E=McAfee;i="6200,9189,10245"; a="246741362" X-IronPort-AV: E=Sophos;i="5.88,336,1635231600"; d="scan'208";a="246741362" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2022 05:15:14 -0800 X-IronPort-AV: E=Sophos;i="5.88,336,1635231600"; d="scan'208";a="620143140" Received: from markeyp-mobl.ger.corp.intel.com (HELO localhost) ([10.252.6.210]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2022 05:15:08 -0800 From: Jani Nikula To: Laurent Pinchart , Kandpal Suraj In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20220202085429.22261-1-suraj.kandpal@intel.com> <20220202085429.22261-6-suraj.kandpal@intel.com> Date: Wed, 02 Feb 2022 15:15:03 +0200 Message-ID: <87y22ts948.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Intel-gfx] [PATCH 5/6] drm/rcar_du: changes to rcar-du driver resulting from drm_writeback_connector structure changes X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: carsten.haitzler@arm.com, intel-gfx@lists.freedesktop.org, quic_abhinavk@quicinc.com, dri-devel@lists.freedesktop.org, dmitry.baryshkov@linaro.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, 02 Feb 2022, Laurent Pinchart wrote: > Hi Kandpal, > > Thank you for the patch. > > On Wed, Feb 02, 2022 at 02:24:28PM +0530, Kandpal Suraj wrote: >> Changing rcar_du driver to accomadate the change of >> drm_writeback_connector.base and drm_writeback_connector.encoder >> to a pointer the reason for which is explained in the >> Patch(drm: add writeback pointers to drm_connector). >> >> Signed-off-by: Kandpal Suraj >> --- >> drivers/gpu/drm/rcar-du/rcar_du_crtc.h | 2 ++ >> drivers/gpu/drm/rcar-du/rcar_du_writeback.c | 8 +++++--- >> 2 files changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.h b/drivers/gpu/drm/rcar-du/rcar_du_crtc.h >> index 66e8839db708..68f387a04502 100644 >> --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.h >> +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.h >> @@ -72,6 +72,8 @@ struct rcar_du_crtc { >> const char *const *sources; >> unsigned int sources_count; >> >> + struct drm_connector connector; >> + struct drm_encoder encoder; > > Those fields are, at best, poorly named. Furthermore, there's no need in > this driver or in other drivers using drm_writeback_connector to create > an encoder or connector manually. Let's not polute all drivers because > i915 doesn't have its abstractions right. i915 uses the quite common model for struct inheritance: struct intel_connector { struct drm_connector base; /* ... */ } Same with at least amd, ast, fsl-dcu, hisilicon, mga200, msm, nouveau, radeon, tilcdc, and vboxvideo. We could argue about the relative merits of that abstraction, but I think the bottom line is that it's popular and the drivers using it are not going to be persuaded to move away from it. It's no coincidence that the drivers who've implemented writeback so far (komeda, mali, rcar-du, vc4, and vkms) do not use the abstraction, because the drm_writeback_connector midlayer does, forcing the issue. So I think drm_writeback_connector should *not* use the inheritance abstraction because it's a midlayer that should leave that option to the drivers. I think drm_writeback_connector needs to be changed to accommodate that, and, unfortunately, it means current writeback users need to be changed as well. I am not sure, however, if the series at hand is the right approach. Perhaps writeback can be modified to allocate the stuff for you if you prefer it that way, as long as the drm_connector is not embedded in struct drm_writeback_connector. BR, Jani. > > Nack. > >> struct drm_writeback_connector writeback; >> }; >> >> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_writeback.c b/drivers/gpu/drm/rcar-du/rcar_du_writeback.c >> index c79d1259e49b..5b1e83380c47 100644 >> --- a/drivers/gpu/drm/rcar-du/rcar_du_writeback.c >> +++ b/drivers/gpu/drm/rcar-du/rcar_du_writeback.c >> @@ -200,8 +200,10 @@ int rcar_du_writeback_init(struct rcar_du_device *rcdu, >> { >> struct drm_writeback_connector *wb_conn = &rcrtc->writeback; >> >> - wb_conn->encoder.possible_crtcs = 1 << drm_crtc_index(&rcrtc->crtc); >> - drm_connector_helper_add(&wb_conn->base, >> + wb_conn->base = &rcrtc->connector; >> + wb_conn->encoder = &rcrtc->encoder; >> + wb_conn->encoder->possible_crtcs = 1 << drm_crtc_index(&rcrtc->crtc); >> + drm_connector_helper_add(wb_conn->base, >> &rcar_du_wb_conn_helper_funcs); >> >> return drm_writeback_connector_init(&rcdu->ddev, wb_conn, >> @@ -220,7 +222,7 @@ void rcar_du_writeback_setup(struct rcar_du_crtc *rcrtc, >> struct drm_framebuffer *fb; >> unsigned int i; >> >> - state = rcrtc->writeback.base.state; >> + state = rcrtc->writeback.base->state; >> if (!state || !state->writeback_job) >> return; >> -- Jani Nikula, Intel Open Source Graphics Center