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 21089C433F5 for ; Fri, 11 Mar 2022 08:06:12 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2BC2010E2C8; Fri, 11 Mar 2022 08:06:12 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6441A10E2C8; Fri, 11 Mar 2022 08:06:11 +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 CAC26488; Fri, 11 Mar 2022 09:06:09 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1646985970; bh=yukh05lLNurYjdrhxyLrN8249mtEL9BDg0pGHOAKYRQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=C7AI2pmG0Y52GXcxJb7eVzHs3UIkyCay/E5W7TWwgBe63BLeYyFklgO3cml2Rv049 8L2XwnyOBbtxEjxDthYmqtYKKI+k0GBEVXpa5VhPcpjyyT2xrXg2c8v6auBuBSX9AC BjpSU7wzSVxR7E6e+Vim/UKa93e+s4VW8l7oFxI8= Date: Fri, 11 Mar 2022 10:05:53 +0200 From: Laurent Pinchart To: Dmitry Baryshkov Subject: Re: [PATCH 1/6] drm: allow real encoder to be passed for drm_writeback_connector Message-ID: References: <1646963400-25606-1-git-send-email-quic_abhinavk@quicinc.com> <1646963400-25606-2-git-send-email-quic_abhinavk@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: 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: hamohammed.sa@gmail.com, suraj.kandpal@intel.com, emma@anholt.net, rodrigosiqueiramelo@gmail.com, jani.nikula@intel.com, liviu.dudau@arm.com, Abhinav Kumar , dri-devel@lists.freedesktop.org, swboyd@chromium.org, melissa.srw@gmail.com, nganji@codeaurora.org, seanpaul@chromium.org, james.qian.wang@arm.com, quic_aravindh@quicinc.com, mihail.atanassov@arm.com, freedreno@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, Mar 11, 2022 at 10:46:13AM +0300, Dmitry Baryshkov wrote: > On Fri, 11 Mar 2022 at 04:50, Abhinav Kumar wrote: > > > > For some vendor driver implementations, display hardware can > > be shared between the encoder used for writeback and the physical > > display. > > > > In addition resources such as clocks and interrupts can > > also be shared between writeback and the real encoder. > > > > To accommodate such vendor drivers and hardware, allow > > real encoder to be passed for drm_writeback_connector. > > > > Co-developed-by: Kandpal Suraj > > Signed-off-by: Abhinav Kumar > > --- > > drivers/gpu/drm/drm_writeback.c | 8 ++++---- > > include/drm/drm_writeback.h | 13 +++++++++++-- > > 2 files changed, 15 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c > > index dccf4504..4dad687 100644 > > --- a/drivers/gpu/drm/drm_writeback.c > > +++ b/drivers/gpu/drm/drm_writeback.c > > @@ -189,8 +189,8 @@ int drm_writeback_connector_init(struct drm_device *dev, > > if (IS_ERR(blob)) > > return PTR_ERR(blob); > > > > - drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs); > > - ret = drm_encoder_init(dev, &wb_connector->encoder, > > + drm_encoder_helper_add(wb_connector->encoder, enc_helper_funcs); > > + ret = drm_encoder_init(dev, wb_connector->encoder, > > &drm_writeback_encoder_funcs, > > DRM_MODE_ENCODER_VIRTUAL, NULL); > > If the encoder is provided by a separate driver, it might use a > different set of encoder funcs. More than that, if the encoder is provided externally but doesn't have custom operations, I don't really see the point of having an external encoder in the first place. Has this series been tested with a driver that needs to provide an encoder, to make sure it fits the purpose ? > I'd suggest checking whether the wb_connector->encoder is NULL here. > If it is, allocate one using drmm_kzalloc and init it. > If it is not NULL, assume that it has been initialized already, so > skip the drm_encoder_init() and just call the drm_encoder_helper_add() > > > if (ret) > > @@ -204,7 +204,7 @@ int drm_writeback_connector_init(struct drm_device *dev, > > goto connector_fail; > > > > ret = drm_connector_attach_encoder(connector, > > - &wb_connector->encoder); > > + wb_connector->encoder); > > if (ret) > > goto attach_fail; > > > > @@ -233,7 +233,7 @@ int drm_writeback_connector_init(struct drm_device *dev, > > attach_fail: > > drm_connector_cleanup(connector); > > connector_fail: > > - drm_encoder_cleanup(&wb_connector->encoder); > > + drm_encoder_cleanup(wb_connector->encoder); > > fail: > > drm_property_blob_put(blob); > > return ret; > > diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h > > index 9697d27..0ba266e 100644 > > --- a/include/drm/drm_writeback.h > > +++ b/include/drm/drm_writeback.h > > @@ -25,13 +25,22 @@ struct drm_writeback_connector { > > struct drm_connector base; > > > > /** > > - * @encoder: Internal encoder used by the connector to fulfill > > + * @encoder: handle to drm_encoder used by the connector to fulfill > > * the DRM framework requirements. The users of the > > * @drm_writeback_connector control the behaviour of the @encoder > > * by passing the @enc_funcs parameter to drm_writeback_connector_init() > > * function. > > + * > > + * For some vendor drivers, the hardware resources are shared between > > + * writeback encoder and rest of the display pipeline. > > + * To accommodate such cases, encoder is a handle to the real encoder > > + * hardware. > > + * > > + * For current existing writeback users, this shall continue to be the > > + * embedded encoder for the writeback connector. > > + * > > */ > > - struct drm_encoder encoder; > > + struct drm_encoder *encoder; > > > > /** > > * @pixel_formats_blob_ptr: -- Regards, Laurent Pinchart