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 26656C433EF for ; Wed, 1 Jun 2022 08:27:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350678AbiFAI1O (ORCPT ); Wed, 1 Jun 2022 04:27:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350621AbiFAI1K (ORCPT ); Wed, 1 Jun 2022 04:27:10 -0400 Received: from mail-ej1-x630.google.com (mail-ej1-x630.google.com [IPv6:2a00:1450:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A54FDE99 for ; Wed, 1 Jun 2022 01:27:04 -0700 (PDT) Received: by mail-ej1-x630.google.com with SMTP id u12so2173024eja.8 for ; Wed, 01 Jun 2022 01:27:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=suGTguNgHNwFoVKJnInY/A0FAKDNS8MrOyf97TQ0XqE=; b=Kz8kZXot4lBQ750zIIvzF3+bHcnNBQtqQzQ1b2o8YXiovCx4t37CQJaYYLktnNzNWJ oiuAIk4+P0ht5DpbHp+/pH42JI/DYgbAj/NglXOGybp75vRdDPoI+c7MEl2u+BKuUcEg G0ED2t7sW1NRpNK8E9QGxnmiTuZCCtBR+LrDM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=suGTguNgHNwFoVKJnInY/A0FAKDNS8MrOyf97TQ0XqE=; b=P0tb/vJoWxlQO0B/OQ06ggoNT6YEcQiqYrF6pSSQ/i/J04wZRBsnXYhc6CprT0dxBo PAd0UVch4sAdzBWEfPNWQmJRtU3x1FBAZ2wlCcxXTp4o8KwhXEFGjSlASx79tTUfjUdM Wmd8PcZWf902ytxfvejm9cnPPrOJbcZ2wuKCaQ7H6iVVq83/oSgmb+zpXJzvBSDPiVeB y9r5x0dEnpK9CCNHGJl5U/Db6Y9WkwANG4ktIBZEbV6sPhBqe8vcxThKzsflaOfXCQTP /9ShCEsv7Ha+4ZEA5d34Gv4pVoBvgv23yElVy8MOwUozUDjym3X/FcgaCUoUwMNZZ6FF Gi0A== X-Gm-Message-State: AOAM530dMaVZhKspdhCZtfctbTLdMuG0g6SQFwyjNy41sjjnY5Pkwwy6 mFifQddW1hooQbj7cN46Ctb5xutVBS0NE5zZZhkEfg== X-Google-Smtp-Source: ABdhPJzKyQ9RhDDQ9wnQwF0m5mvEJpb5dxyTIDWPhvbLIROaZRgzrB121HfZ6Kvw/3Mtkh8DpWUjMyD3cSjoY6y1xU0= X-Received: by 2002:a17:906:d7ba:b0:6fe:a119:c4ac with SMTP id pk26-20020a170906d7ba00b006fea119c4acmr54450591ejb.129.1654072023238; Wed, 01 Jun 2022 01:27:03 -0700 (PDT) MIME-Version: 1.0 References: <20220530081910.3947168-1-hsinyi@chromium.org> <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> In-Reply-To: <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> From: Hsin-Yi Wang Date: Wed, 1 Jun 2022 16:26:37 +0800 Message-ID: Subject: Re: [PATCH v10 0/4] Separate panel orientation property creating and value setting To: Hans de Goede Cc: dri-devel@lists.freedesktop.org, David Airlie , Daniel Vetter , amd-gfx@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, Rob Clark , Stephen Boyd , Douglas Anderson , Chun-Kuang Hu , Sean Paul , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , linux-kernel@vger.kernel.org, Rob Herring , Matthias Brugger , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Simon Ser , Harry Wentland , Alex Deucher , Jani Nikula , Emil Velikov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 31, 2022 at 6:56 PM Hans de Goede wrote: > > Hi, > > On 5/30/22 13:34, Hsin-Yi Wang wrote: > > On Mon, May 30, 2022 at 4:53 PM Hans de Goede wrote: > >> > >> Hi, > >> > >> On 5/30/22 10:19, Hsin-Yi Wang wrote: > >>> Some drivers, eg. mtk_drm and msm_drm, rely on the panel to set the > >>> orientation. Panel calls drm_connector_set_panel_orientation() to create > >>> orientation property and sets the value. However, connector properties > >>> can't be created after drm_dev_register() is called. The goal is to > >>> separate the orientation property creation, so drm drivers can create it > >>> earlier before drm_dev_register(). > >> > >> Sorry for jumping in pretty late in the discussion (based on the v10 > >> I seem to have missed this before). > >> > >> This sounds to me like the real issue here is that drm_dev_register() > >> is getting called too early? > >> > > Right. > > > >> To me it seems sensible to delay calling drm_dev_register() and > >> thus allowing userspace to start detecting available displays + > >> features until after the panel has been probed. > >> > > > > Most panels set this value very late, in .get_modes callback (since it > > is when the connector is known), though the value was known during > > panel probe. > > Hmm I would expect the main drm/kms driver to register the drm_connector > object after probing the panel, right ? > > So maybe this is a problem with the panel API? How about adding > separate callback to the panel API to get the orientation, which the > main drm/kms driver can then call before registering the connector ? > > And then have the main drm/kms driver call > drm_connector_set_panel_orientation() with the returned orientation > on the connecter before registering it. > > The new get_orientation callback for the panel should of course > be optional (IOW amy be NULL), so we probably want a small > helper for drivers using panel (sub)drivers to take care of > the process of getting the panel orientation from the panel > (if supported) and then setting it on the connector. > Hi Hans, Thanks for the suggestion. I've sent a new version for this: https://patchwork.kernel.org/project/dri-devel/patch/20220601081823.1038797-2-hsinyi@chromium.org/ Panel can implement the optional callback to return the orientation property, while drm/kms driver will call a drm API to get the value then they can call drm_connector_set_panel_orientation(). Panel .get_mode will still call drm_connector_set_panel_orientation() but now it will be a no-op as the value was set by drm/kms driver previously. This is similar to the small patch below: https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ But it's now using the panel API. > > > I think we can also let drm check if they have remote panel nodes: If > > there is a panel and the panel sets the orientation, let the drm read > > this value and set the property. Does this workflow sound reasonable? > > > > The corresponding patch to implement this: > > https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ > > That is a suprisingly small patch (which is good). I guess that > my suggestion to add a new panel driver callback to get > the orientation would be a bit bigget then this. Still I think > that that would be a bit cleaner, as it would also solve this > for cases where the orientation comes from the panel itself > (through say some EDID extenstion) rather then from devicetree. > > Still I think either way should be acceptable upstream. > > Opinions from other drm devs on the above are very much welcome! > > Your small patch nicely avoids the probe ordering problem, > so it is much better then this patch series. > > Regards, > > Hans > > > > > > > Thanks > > > >> I see a devicetree patch in this series, so I guess that the panel > >> is described in devicetree. Especially in the case of devicetree > >> I would expect the kernel to have enough info to do the right > >> thing and make sure the panel is probed before calling > >> drm_dev_register() ? > >> > >> Regards, > >> > >> Hans > >> > >> > >> > >> > >>> > >>> After this series, drm_connector_set_panel_orientation() works like > >>> before. It won't affect existing callers of > >>> drm_connector_set_panel_orientation(). The only difference is that > >>> some drm drivers can call drm_connector_init_panel_orientation_property() > >>> earlier. > >>> > >>> Hsin-Yi Wang (4): > >>> gpu: drm: separate panel orientation property creating and value > >>> setting > >>> drm/mediatek: init panel orientation property > >>> drm/msm: init panel orientation property > >>> arm64: dts: mt8183: Add panel rotation > >>> > >>> .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi | 1 + > >>> drivers/gpu/drm/drm_connector.c | 58 ++++++++++++++----- > >>> drivers/gpu/drm/mediatek/mtk_dsi.c | 7 +++ > >>> drivers/gpu/drm/msm/dsi/dsi_manager.c | 4 ++ > >>> include/drm/drm_connector.h | 2 + > >>> 5 files changed, 59 insertions(+), 13 deletions(-) > >>> > >> > > > 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 7B7F1C433F5 for ; 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Wed, 01 Jun 2022 01:27:03 -0700 (PDT) MIME-Version: 1.0 References: <20220530081910.3947168-1-hsinyi@chromium.org> <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> In-Reply-To: <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> From: Hsin-Yi Wang Date: Wed, 1 Jun 2022 16:26:37 +0800 Message-ID: Subject: Re: [PATCH v10 0/4] Separate panel orientation property creating and value setting To: Hans de Goede Cc: dri-devel@lists.freedesktop.org, David Airlie , Daniel Vetter , amd-gfx@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, Rob Clark , Stephen Boyd , Douglas Anderson , Chun-Kuang Hu , Sean Paul , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , linux-kernel@vger.kernel.org, Rob Herring , Matthias Brugger , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Simon Ser , Harry Wentland , Alex Deucher , Jani Nikula , Emil Velikov X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220601_012705_090352_E9324B5E X-CRM114-Status: GOOD ( 47.98 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Tue, May 31, 2022 at 6:56 PM Hans de Goede wrote: > > Hi, > > On 5/30/22 13:34, Hsin-Yi Wang wrote: > > On Mon, May 30, 2022 at 4:53 PM Hans de Goede wrote: > >> > >> Hi, > >> > >> On 5/30/22 10:19, Hsin-Yi Wang wrote: > >>> Some drivers, eg. mtk_drm and msm_drm, rely on the panel to set the > >>> orientation. Panel calls drm_connector_set_panel_orientation() to create > >>> orientation property and sets the value. However, connector properties > >>> can't be created after drm_dev_register() is called. The goal is to > >>> separate the orientation property creation, so drm drivers can create it > >>> earlier before drm_dev_register(). > >> > >> Sorry for jumping in pretty late in the discussion (based on the v10 > >> I seem to have missed this before). > >> > >> This sounds to me like the real issue here is that drm_dev_register() > >> is getting called too early? > >> > > Right. > > > >> To me it seems sensible to delay calling drm_dev_register() and > >> thus allowing userspace to start detecting available displays + > >> features until after the panel has been probed. > >> > > > > Most panels set this value very late, in .get_modes callback (since it > > is when the connector is known), though the value was known during > > panel probe. > > Hmm I would expect the main drm/kms driver to register the drm_connector > object after probing the panel, right ? > > So maybe this is a problem with the panel API? How about adding > separate callback to the panel API to get the orientation, which the > main drm/kms driver can then call before registering the connector ? > > And then have the main drm/kms driver call > drm_connector_set_panel_orientation() with the returned orientation > on the connecter before registering it. > > The new get_orientation callback for the panel should of course > be optional (IOW amy be NULL), so we probably want a small > helper for drivers using panel (sub)drivers to take care of > the process of getting the panel orientation from the panel > (if supported) and then setting it on the connector. > Hi Hans, Thanks for the suggestion. I've sent a new version for this: https://patchwork.kernel.org/project/dri-devel/patch/20220601081823.1038797-2-hsinyi@chromium.org/ Panel can implement the optional callback to return the orientation property, while drm/kms driver will call a drm API to get the value then they can call drm_connector_set_panel_orientation(). Panel .get_mode will still call drm_connector_set_panel_orientation() but now it will be a no-op as the value was set by drm/kms driver previously. This is similar to the small patch below: https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ But it's now using the panel API. > > > I think we can also let drm check if they have remote panel nodes: If > > there is a panel and the panel sets the orientation, let the drm read > > this value and set the property. Does this workflow sound reasonable? > > > > The corresponding patch to implement this: > > https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ > > That is a suprisingly small patch (which is good). I guess that > my suggestion to add a new panel driver callback to get > the orientation would be a bit bigget then this. Still I think > that that would be a bit cleaner, as it would also solve this > for cases where the orientation comes from the panel itself > (through say some EDID extenstion) rather then from devicetree. > > Still I think either way should be acceptable upstream. > > Opinions from other drm devs on the above are very much welcome! > > Your small patch nicely avoids the probe ordering problem, > so it is much better then this patch series. > > Regards, > > Hans > > > > > > > Thanks > > > >> I see a devicetree patch in this series, so I guess that the panel > >> is described in devicetree. Especially in the case of devicetree > >> I would expect the kernel to have enough info to do the right > >> thing and make sure the panel is probed before calling > >> drm_dev_register() ? > >> > >> Regards, > >> > >> Hans > >> > >> > >> > >> > >>> > >>> After this series, drm_connector_set_panel_orientation() works like > >>> before. It won't affect existing callers of > >>> drm_connector_set_panel_orientation(). The only difference is that > >>> some drm drivers can call drm_connector_init_panel_orientation_property() > >>> earlier. > >>> > >>> Hsin-Yi Wang (4): > >>> gpu: drm: separate panel orientation property creating and value > >>> setting > >>> drm/mediatek: init panel orientation property > >>> drm/msm: init panel orientation property > >>> arm64: dts: mt8183: Add panel rotation > >>> > >>> .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi | 1 + > >>> drivers/gpu/drm/drm_connector.c | 58 ++++++++++++++----- > >>> drivers/gpu/drm/mediatek/mtk_dsi.c | 7 +++ > >>> drivers/gpu/drm/msm/dsi/dsi_manager.c | 4 ++ > >>> include/drm/drm_connector.h | 2 + > >>> 5 files changed, 59 insertions(+), 13 deletions(-) > >>> > >> > > > _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek 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 0777FC433F5 for ; Wed, 1 Jun 2022 08:27:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 42E9910E896; Wed, 1 Jun 2022 08:27:06 +0000 (UTC) Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by gabe.freedesktop.org (Postfix) with ESMTPS id DA83610E896 for ; Wed, 1 Jun 2022 08:27:04 +0000 (UTC) Received: by mail-ej1-x62c.google.com with SMTP id q1so2160717ejz.9 for ; Wed, 01 Jun 2022 01:27:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=suGTguNgHNwFoVKJnInY/A0FAKDNS8MrOyf97TQ0XqE=; b=Kz8kZXot4lBQ750zIIvzF3+bHcnNBQtqQzQ1b2o8YXiovCx4t37CQJaYYLktnNzNWJ oiuAIk4+P0ht5DpbHp+/pH42JI/DYgbAj/NglXOGybp75vRdDPoI+c7MEl2u+BKuUcEg G0ED2t7sW1NRpNK8E9QGxnmiTuZCCtBR+LrDM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=suGTguNgHNwFoVKJnInY/A0FAKDNS8MrOyf97TQ0XqE=; b=m++3eJ6wLHcRIErurFGordiYdBaGauQjieML19qIjMcVlP3dtVVo+f3PGaoQtgWV+L 7+izc+OwIhRT7ig5hM/vn0tdZotyTJJC+i8SQH3Bp0gDr+s4smpFDFtxMs+XLqhJjHbc rjTHqiQrK8/G/mh72kJyBY5tOM6MkP+CfD5bQ/z+gUWav21++Uxtxm7/U3r/DN5tsxUf Cb6NXzPoaBN9Q2V/rcNMrXBxE+94uCGXatC1OIRMPS48ArVszun98Wz1jjMSvNNfWPX7 yYt7odOXmzKpSj/v7RQ9UejIEr9wimSMs2qa8uisLDRMZqtkGcrXM2yaw1+26lUhpJ0/ K11g== X-Gm-Message-State: AOAM5312AtR783ejpAopDxfdm+VQ+5KErN1+p0U/caF0gIaWG/AQEr0g Ue+oFTcYdLEUo45iXcTJPlS5YaVyDuuvTSLxNOch9w== X-Google-Smtp-Source: ABdhPJzKyQ9RhDDQ9wnQwF0m5mvEJpb5dxyTIDWPhvbLIROaZRgzrB121HfZ6Kvw/3Mtkh8DpWUjMyD3cSjoY6y1xU0= X-Received: by 2002:a17:906:d7ba:b0:6fe:a119:c4ac with SMTP id pk26-20020a170906d7ba00b006fea119c4acmr54450591ejb.129.1654072023238; Wed, 01 Jun 2022 01:27:03 -0700 (PDT) MIME-Version: 1.0 References: <20220530081910.3947168-1-hsinyi@chromium.org> <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> In-Reply-To: <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> From: Hsin-Yi Wang Date: Wed, 1 Jun 2022 16:26:37 +0800 Message-ID: Subject: Re: [PATCH v10 0/4] Separate panel orientation property creating and value setting To: Hans de Goede Content-Type: text/plain; charset="UTF-8" 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, David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Rob Clark , amd-gfx@lists.freedesktop.org, Chun-Kuang Hu , intel-gfx@lists.freedesktop.org, Stephen Boyd , Rob Herring , linux-mediatek@lists.infradead.org, Matthias Brugger , Sean Paul , linux-arm-kernel@lists.infradead.org, Emil Velikov , Douglas Anderson , Thomas Zimmermann , Alex Deucher Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Tue, May 31, 2022 at 6:56 PM Hans de Goede wrote: > > Hi, > > On 5/30/22 13:34, Hsin-Yi Wang wrote: > > On Mon, May 30, 2022 at 4:53 PM Hans de Goede wrote: > >> > >> Hi, > >> > >> On 5/30/22 10:19, Hsin-Yi Wang wrote: > >>> Some drivers, eg. mtk_drm and msm_drm, rely on the panel to set the > >>> orientation. Panel calls drm_connector_set_panel_orientation() to create > >>> orientation property and sets the value. However, connector properties > >>> can't be created after drm_dev_register() is called. The goal is to > >>> separate the orientation property creation, so drm drivers can create it > >>> earlier before drm_dev_register(). > >> > >> Sorry for jumping in pretty late in the discussion (based on the v10 > >> I seem to have missed this before). > >> > >> This sounds to me like the real issue here is that drm_dev_register() > >> is getting called too early? > >> > > Right. > > > >> To me it seems sensible to delay calling drm_dev_register() and > >> thus allowing userspace to start detecting available displays + > >> features until after the panel has been probed. > >> > > > > Most panels set this value very late, in .get_modes callback (since it > > is when the connector is known), though the value was known during > > panel probe. > > Hmm I would expect the main drm/kms driver to register the drm_connector > object after probing the panel, right ? > > So maybe this is a problem with the panel API? How about adding > separate callback to the panel API to get the orientation, which the > main drm/kms driver can then call before registering the connector ? > > And then have the main drm/kms driver call > drm_connector_set_panel_orientation() with the returned orientation > on the connecter before registering it. > > The new get_orientation callback for the panel should of course > be optional (IOW amy be NULL), so we probably want a small > helper for drivers using panel (sub)drivers to take care of > the process of getting the panel orientation from the panel > (if supported) and then setting it on the connector. > Hi Hans, Thanks for the suggestion. I've sent a new version for this: https://patchwork.kernel.org/project/dri-devel/patch/20220601081823.1038797-2-hsinyi@chromium.org/ Panel can implement the optional callback to return the orientation property, while drm/kms driver will call a drm API to get the value then they can call drm_connector_set_panel_orientation(). Panel .get_mode will still call drm_connector_set_panel_orientation() but now it will be a no-op as the value was set by drm/kms driver previously. This is similar to the small patch below: https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ But it's now using the panel API. > > > I think we can also let drm check if they have remote panel nodes: If > > there is a panel and the panel sets the orientation, let the drm read > > this value and set the property. Does this workflow sound reasonable? > > > > The corresponding patch to implement this: > > https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ > > That is a suprisingly small patch (which is good). I guess that > my suggestion to add a new panel driver callback to get > the orientation would be a bit bigget then this. Still I think > that that would be a bit cleaner, as it would also solve this > for cases where the orientation comes from the panel itself > (through say some EDID extenstion) rather then from devicetree. > > Still I think either way should be acceptable upstream. > > Opinions from other drm devs on the above are very much welcome! > > Your small patch nicely avoids the probe ordering problem, > so it is much better then this patch series. > > Regards, > > Hans > > > > > > > Thanks > > > >> I see a devicetree patch in this series, so I guess that the panel > >> is described in devicetree. Especially in the case of devicetree > >> I would expect the kernel to have enough info to do the right > >> thing and make sure the panel is probed before calling > >> drm_dev_register() ? > >> > >> Regards, > >> > >> Hans > >> > >> > >> > >> > >>> > >>> After this series, drm_connector_set_panel_orientation() works like > >>> before. It won't affect existing callers of > >>> drm_connector_set_panel_orientation(). The only difference is that > >>> some drm drivers can call drm_connector_init_panel_orientation_property() > >>> earlier. > >>> > >>> Hsin-Yi Wang (4): > >>> gpu: drm: separate panel orientation property creating and value > >>> setting > >>> drm/mediatek: init panel orientation property > >>> drm/msm: init panel orientation property > >>> arm64: dts: mt8183: Add panel rotation > >>> > >>> .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi | 1 + > >>> drivers/gpu/drm/drm_connector.c | 58 ++++++++++++++----- > >>> drivers/gpu/drm/mediatek/mtk_dsi.c | 7 +++ > >>> drivers/gpu/drm/msm/dsi/dsi_manager.c | 4 ++ > >>> include/drm/drm_connector.h | 2 + > >>> 5 files changed, 59 insertions(+), 13 deletions(-) > >>> > >> > > > 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 D2B57C433EF for ; Wed, 1 Jun 2022 08:27:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 78DC110E887; Wed, 1 Jun 2022 08:27:05 +0000 (UTC) Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) by gabe.freedesktop.org (Postfix) with ESMTPS id DC76C10E8A0 for ; Wed, 1 Jun 2022 08:27:04 +0000 (UTC) Received: by mail-ej1-x62e.google.com with SMTP id m20so2148941ejj.10 for ; Wed, 01 Jun 2022 01:27:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=suGTguNgHNwFoVKJnInY/A0FAKDNS8MrOyf97TQ0XqE=; b=Kz8kZXot4lBQ750zIIvzF3+bHcnNBQtqQzQ1b2o8YXiovCx4t37CQJaYYLktnNzNWJ oiuAIk4+P0ht5DpbHp+/pH42JI/DYgbAj/NglXOGybp75vRdDPoI+c7MEl2u+BKuUcEg G0ED2t7sW1NRpNK8E9QGxnmiTuZCCtBR+LrDM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=suGTguNgHNwFoVKJnInY/A0FAKDNS8MrOyf97TQ0XqE=; b=hl+WifiK1zcisp6fpKqPzNDbI2PrzxfEzWPqM5foG3vzV+dpJBCKrWjgAY2U2YHhvb mmPG/F8h+ZjR529NF1qcFdG6Aeo96pvKebcX+rPDwxqoDGc97onBZyr6upXr+Cz+sjeT /38mOnHhElERG+Vl4cdpzR1GhgotOnwOxtHC8YiXLQWb7fnxfV85deSUihlPpg+fdfiJ T0JlyfSCb6uZshHjq78ygU1ekuiBO0676ouDT/l5itBsFs+dZ8FayrMZUFWDqCtD2fZ7 sjg9x3u48567/o/zGqf0rXuAn6D6ffgESvB4YGHn26j6Y6zcDBDys1DKzTxDekNsRE/1 0Wrg== X-Gm-Message-State: AOAM532FW8OJDAZUWCd0Vl7JozYNLmz65xzsw6i3C/3wUxn5l6LlCQn6 G3dYR9uCRGLRus3SKISPzKbBhqjRP/Grxadv+chWbQ== X-Google-Smtp-Source: ABdhPJzKyQ9RhDDQ9wnQwF0m5mvEJpb5dxyTIDWPhvbLIROaZRgzrB121HfZ6Kvw/3Mtkh8DpWUjMyD3cSjoY6y1xU0= X-Received: by 2002:a17:906:d7ba:b0:6fe:a119:c4ac with SMTP id pk26-20020a170906d7ba00b006fea119c4acmr54450591ejb.129.1654072023238; Wed, 01 Jun 2022 01:27:03 -0700 (PDT) MIME-Version: 1.0 References: <20220530081910.3947168-1-hsinyi@chromium.org> <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> In-Reply-To: <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> From: Hsin-Yi Wang Date: Wed, 1 Jun 2022 16:26:37 +0800 Message-ID: To: Hans de Goede Content-Type: text/plain; charset="UTF-8" Subject: Re: [Intel-gfx] [PATCH v10 0/4] Separate panel orientation property creating and value setting 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: devicetree@vger.kernel.org, David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Rob Clark , amd-gfx@lists.freedesktop.org, Harry Wentland , Chun-Kuang Hu , intel-gfx@lists.freedesktop.org, Maxime Ripard , Stephen Boyd , Rob Herring , linux-mediatek@lists.infradead.org, Matthias Brugger , linux-arm-kernel@lists.infradead.org, Simon Ser , Douglas Anderson , Thomas Zimmermann , Alex Deucher Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, May 31, 2022 at 6:56 PM Hans de Goede wrote: > > Hi, > > On 5/30/22 13:34, Hsin-Yi Wang wrote: > > On Mon, May 30, 2022 at 4:53 PM Hans de Goede wrote: > >> > >> Hi, > >> > >> On 5/30/22 10:19, Hsin-Yi Wang wrote: > >>> Some drivers, eg. mtk_drm and msm_drm, rely on the panel to set the > >>> orientation. Panel calls drm_connector_set_panel_orientation() to create > >>> orientation property and sets the value. However, connector properties > >>> can't be created after drm_dev_register() is called. The goal is to > >>> separate the orientation property creation, so drm drivers can create it > >>> earlier before drm_dev_register(). > >> > >> Sorry for jumping in pretty late in the discussion (based on the v10 > >> I seem to have missed this before). > >> > >> This sounds to me like the real issue here is that drm_dev_register() > >> is getting called too early? > >> > > Right. > > > >> To me it seems sensible to delay calling drm_dev_register() and > >> thus allowing userspace to start detecting available displays + > >> features until after the panel has been probed. > >> > > > > Most panels set this value very late, in .get_modes callback (since it > > is when the connector is known), though the value was known during > > panel probe. > > Hmm I would expect the main drm/kms driver to register the drm_connector > object after probing the panel, right ? > > So maybe this is a problem with the panel API? How about adding > separate callback to the panel API to get the orientation, which the > main drm/kms driver can then call before registering the connector ? > > And then have the main drm/kms driver call > drm_connector_set_panel_orientation() with the returned orientation > on the connecter before registering it. > > The new get_orientation callback for the panel should of course > be optional (IOW amy be NULL), so we probably want a small > helper for drivers using panel (sub)drivers to take care of > the process of getting the panel orientation from the panel > (if supported) and then setting it on the connector. > Hi Hans, Thanks for the suggestion. I've sent a new version for this: https://patchwork.kernel.org/project/dri-devel/patch/20220601081823.1038797-2-hsinyi@chromium.org/ Panel can implement the optional callback to return the orientation property, while drm/kms driver will call a drm API to get the value then they can call drm_connector_set_panel_orientation(). Panel .get_mode will still call drm_connector_set_panel_orientation() but now it will be a no-op as the value was set by drm/kms driver previously. This is similar to the small patch below: https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ But it's now using the panel API. > > > I think we can also let drm check if they have remote panel nodes: If > > there is a panel and the panel sets the orientation, let the drm read > > this value and set the property. Does this workflow sound reasonable? > > > > The corresponding patch to implement this: > > https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ > > That is a suprisingly small patch (which is good). I guess that > my suggestion to add a new panel driver callback to get > the orientation would be a bit bigget then this. Still I think > that that would be a bit cleaner, as it would also solve this > for cases where the orientation comes from the panel itself > (through say some EDID extenstion) rather then from devicetree. > > Still I think either way should be acceptable upstream. > > Opinions from other drm devs on the above are very much welcome! > > Your small patch nicely avoids the probe ordering problem, > so it is much better then this patch series. > > Regards, > > Hans > > > > > > > Thanks > > > >> I see a devicetree patch in this series, so I guess that the panel > >> is described in devicetree. Especially in the case of devicetree > >> I would expect the kernel to have enough info to do the right > >> thing and make sure the panel is probed before calling > >> drm_dev_register() ? > >> > >> Regards, > >> > >> Hans > >> > >> > >> > >> > >>> > >>> After this series, drm_connector_set_panel_orientation() works like > >>> before. It won't affect existing callers of > >>> drm_connector_set_panel_orientation(). The only difference is that > >>> some drm drivers can call drm_connector_init_panel_orientation_property() > >>> earlier. > >>> > >>> Hsin-Yi Wang (4): > >>> gpu: drm: separate panel orientation property creating and value > >>> setting > >>> drm/mediatek: init panel orientation property > >>> drm/msm: init panel orientation property > >>> arm64: dts: mt8183: Add panel rotation > >>> > >>> .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi | 1 + > >>> drivers/gpu/drm/drm_connector.c | 58 ++++++++++++++----- > >>> drivers/gpu/drm/mediatek/mtk_dsi.c | 7 +++ > >>> drivers/gpu/drm/msm/dsi/dsi_manager.c | 4 ++ > >>> include/drm/drm_connector.h | 2 + > >>> 5 files changed, 59 insertions(+), 13 deletions(-) > >>> > >> > > > 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 AA85CC433EF for ; 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Wed, 01 Jun 2022 01:27:03 -0700 (PDT) MIME-Version: 1.0 References: <20220530081910.3947168-1-hsinyi@chromium.org> <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> In-Reply-To: <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> From: Hsin-Yi Wang Date: Wed, 1 Jun 2022 16:26:37 +0800 Message-ID: Subject: Re: [PATCH v10 0/4] Separate panel orientation property creating and value setting To: Hans de Goede Cc: dri-devel@lists.freedesktop.org, David Airlie , Daniel Vetter , amd-gfx@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, Rob Clark , Stephen Boyd , Douglas Anderson , Chun-Kuang Hu , Sean Paul , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , linux-kernel@vger.kernel.org, Rob Herring , Matthias Brugger , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Simon Ser , Harry Wentland , Alex Deucher , Jani Nikula , Emil Velikov X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220601_012707_190004_B1D3D9B6 X-CRM114-Status: GOOD ( 49.29 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, May 31, 2022 at 6:56 PM Hans de Goede wrote: > > Hi, > > On 5/30/22 13:34, Hsin-Yi Wang wrote: > > On Mon, May 30, 2022 at 4:53 PM Hans de Goede wrote: > >> > >> Hi, > >> > >> On 5/30/22 10:19, Hsin-Yi Wang wrote: > >>> Some drivers, eg. mtk_drm and msm_drm, rely on the panel to set the > >>> orientation. Panel calls drm_connector_set_panel_orientation() to create > >>> orientation property and sets the value. However, connector properties > >>> can't be created after drm_dev_register() is called. The goal is to > >>> separate the orientation property creation, so drm drivers can create it > >>> earlier before drm_dev_register(). > >> > >> Sorry for jumping in pretty late in the discussion (based on the v10 > >> I seem to have missed this before). > >> > >> This sounds to me like the real issue here is that drm_dev_register() > >> is getting called too early? > >> > > Right. > > > >> To me it seems sensible to delay calling drm_dev_register() and > >> thus allowing userspace to start detecting available displays + > >> features until after the panel has been probed. > >> > > > > Most panels set this value very late, in .get_modes callback (since it > > is when the connector is known), though the value was known during > > panel probe. > > Hmm I would expect the main drm/kms driver to register the drm_connector > object after probing the panel, right ? > > So maybe this is a problem with the panel API? How about adding > separate callback to the panel API to get the orientation, which the > main drm/kms driver can then call before registering the connector ? > > And then have the main drm/kms driver call > drm_connector_set_panel_orientation() with the returned orientation > on the connecter before registering it. > > The new get_orientation callback for the panel should of course > be optional (IOW amy be NULL), so we probably want a small > helper for drivers using panel (sub)drivers to take care of > the process of getting the panel orientation from the panel > (if supported) and then setting it on the connector. > Hi Hans, Thanks for the suggestion. I've sent a new version for this: https://patchwork.kernel.org/project/dri-devel/patch/20220601081823.1038797-2-hsinyi@chromium.org/ Panel can implement the optional callback to return the orientation property, while drm/kms driver will call a drm API to get the value then they can call drm_connector_set_panel_orientation(). Panel .get_mode will still call drm_connector_set_panel_orientation() but now it will be a no-op as the value was set by drm/kms driver previously. This is similar to the small patch below: https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ But it's now using the panel API. > > > I think we can also let drm check if they have remote panel nodes: If > > there is a panel and the panel sets the orientation, let the drm read > > this value and set the property. Does this workflow sound reasonable? > > > > The corresponding patch to implement this: > > https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ > > That is a suprisingly small patch (which is good). I guess that > my suggestion to add a new panel driver callback to get > the orientation would be a bit bigget then this. Still I think > that that would be a bit cleaner, as it would also solve this > for cases where the orientation comes from the panel itself > (through say some EDID extenstion) rather then from devicetree. > > Still I think either way should be acceptable upstream. > > Opinions from other drm devs on the above are very much welcome! > > Your small patch nicely avoids the probe ordering problem, > so it is much better then this patch series. > > Regards, > > Hans > > > > > > > Thanks > > > >> I see a devicetree patch in this series, so I guess that the panel > >> is described in devicetree. Especially in the case of devicetree > >> I would expect the kernel to have enough info to do the right > >> thing and make sure the panel is probed before calling > >> drm_dev_register() ? > >> > >> Regards, > >> > >> Hans > >> > >> > >> > >> > >>> > >>> After this series, drm_connector_set_panel_orientation() works like > >>> before. It won't affect existing callers of > >>> drm_connector_set_panel_orientation(). The only difference is that > >>> some drm drivers can call drm_connector_init_panel_orientation_property() > >>> earlier. > >>> > >>> Hsin-Yi Wang (4): > >>> gpu: drm: separate panel orientation property creating and value > >>> setting > >>> drm/mediatek: init panel orientation property > >>> drm/msm: init panel orientation property > >>> arm64: dts: mt8183: Add panel rotation > >>> > >>> .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi | 1 + > >>> drivers/gpu/drm/drm_connector.c | 58 ++++++++++++++----- > >>> drivers/gpu/drm/mediatek/mtk_dsi.c | 7 +++ > >>> drivers/gpu/drm/msm/dsi/dsi_manager.c | 4 ++ > >>> include/drm/drm_connector.h | 2 + > >>> 5 files changed, 59 insertions(+), 13 deletions(-) > >>> > >> > > > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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 F3A4EC433EF for ; Wed, 1 Jun 2022 14:04:06 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 95D3210EB4D; Wed, 1 Jun 2022 14:04:06 +0000 (UTC) Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by gabe.freedesktop.org (Postfix) with ESMTPS id D494510E887 for ; Wed, 1 Jun 2022 08:27:04 +0000 (UTC) Received: by mail-ej1-x631.google.com with SMTP id f21so2146727ejh.11 for ; Wed, 01 Jun 2022 01:27:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=suGTguNgHNwFoVKJnInY/A0FAKDNS8MrOyf97TQ0XqE=; b=Kz8kZXot4lBQ750zIIvzF3+bHcnNBQtqQzQ1b2o8YXiovCx4t37CQJaYYLktnNzNWJ oiuAIk4+P0ht5DpbHp+/pH42JI/DYgbAj/NglXOGybp75vRdDPoI+c7MEl2u+BKuUcEg G0ED2t7sW1NRpNK8E9QGxnmiTuZCCtBR+LrDM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=suGTguNgHNwFoVKJnInY/A0FAKDNS8MrOyf97TQ0XqE=; b=rq65EGsPcoSAoUFzM4n9OIAD1kKgNdTkwi1/g7pjOagOgulXNF+CjfGzgdZdrem8NB dR1HW77eEkn1KaUV9vnL0VFqwv62cmwuZxxlFMYdNaoEEMqdqNGR+Y7FTA+rBE3Z4mgj 0JWyeaXtxr4me4Ua200+LHoGrl7S7mda6F2uTttwBK0+OsWZ9TSFBLffG9YLEjkCTyRS HUGMo/tXV9SW//NSsHC+RYOx5Tkohy2JtpQmc8DNRCM3ueeLiKhKdkAkdJEQ08MtDq8D OvAS3hLrt9G9+85a5ex4zNE8UM5hHdXQFyjWa0lGNv80rKgzNT/3JHR6zuIuvl5FqbyB M/Mg== X-Gm-Message-State: AOAM5309Uds9p+0nqHKRxopgUt9oICPo1kdL0Y/MaSo7xNin/wGB8iof WM2iFyTMpT1XXKGewGpvnC0yKwPtH82P4+wbo97Ncg== X-Google-Smtp-Source: ABdhPJzKyQ9RhDDQ9wnQwF0m5mvEJpb5dxyTIDWPhvbLIROaZRgzrB121HfZ6Kvw/3Mtkh8DpWUjMyD3cSjoY6y1xU0= X-Received: by 2002:a17:906:d7ba:b0:6fe:a119:c4ac with SMTP id pk26-20020a170906d7ba00b006fea119c4acmr54450591ejb.129.1654072023238; Wed, 01 Jun 2022 01:27:03 -0700 (PDT) MIME-Version: 1.0 References: <20220530081910.3947168-1-hsinyi@chromium.org> <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> In-Reply-To: <5ba0b86a-fa9c-ed97-3b43-7814599deab5@redhat.com> From: Hsin-Yi Wang Date: Wed, 1 Jun 2022 16:26:37 +0800 Message-ID: Subject: Re: [PATCH v10 0/4] Separate panel orientation property creating and value setting To: Hans de Goede Content-Type: text/plain; charset="UTF-8" X-Mailman-Approved-At: Wed, 01 Jun 2022 14:04:05 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Rob Clark , amd-gfx@lists.freedesktop.org, Harry Wentland , Chun-Kuang Hu , Daniel Vetter , intel-gfx@lists.freedesktop.org, Maarten Lankhorst , Maxime Ripard , Stephen Boyd , Rob Herring , linux-mediatek@lists.infradead.org, Jani Nikula , Matthias Brugger , Sean Paul , linux-arm-kernel@lists.infradead.org, Simon Ser , Emil Velikov , Douglas Anderson , Thomas Zimmermann , Alex Deucher Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" On Tue, May 31, 2022 at 6:56 PM Hans de Goede wrote: > > Hi, > > On 5/30/22 13:34, Hsin-Yi Wang wrote: > > On Mon, May 30, 2022 at 4:53 PM Hans de Goede wrote: > >> > >> Hi, > >> > >> On 5/30/22 10:19, Hsin-Yi Wang wrote: > >>> Some drivers, eg. mtk_drm and msm_drm, rely on the panel to set the > >>> orientation. Panel calls drm_connector_set_panel_orientation() to create > >>> orientation property and sets the value. However, connector properties > >>> can't be created after drm_dev_register() is called. The goal is to > >>> separate the orientation property creation, so drm drivers can create it > >>> earlier before drm_dev_register(). > >> > >> Sorry for jumping in pretty late in the discussion (based on the v10 > >> I seem to have missed this before). > >> > >> This sounds to me like the real issue here is that drm_dev_register() > >> is getting called too early? > >> > > Right. > > > >> To me it seems sensible to delay calling drm_dev_register() and > >> thus allowing userspace to start detecting available displays + > >> features until after the panel has been probed. > >> > > > > Most panels set this value very late, in .get_modes callback (since it > > is when the connector is known), though the value was known during > > panel probe. > > Hmm I would expect the main drm/kms driver to register the drm_connector > object after probing the panel, right ? > > So maybe this is a problem with the panel API? How about adding > separate callback to the panel API to get the orientation, which the > main drm/kms driver can then call before registering the connector ? > > And then have the main drm/kms driver call > drm_connector_set_panel_orientation() with the returned orientation > on the connecter before registering it. > > The new get_orientation callback for the panel should of course > be optional (IOW amy be NULL), so we probably want a small > helper for drivers using panel (sub)drivers to take care of > the process of getting the panel orientation from the panel > (if supported) and then setting it on the connector. > Hi Hans, Thanks for the suggestion. I've sent a new version for this: https://patchwork.kernel.org/project/dri-devel/patch/20220601081823.1038797-2-hsinyi@chromium.org/ Panel can implement the optional callback to return the orientation property, while drm/kms driver will call a drm API to get the value then they can call drm_connector_set_panel_orientation(). Panel .get_mode will still call drm_connector_set_panel_orientation() but now it will be a no-op as the value was set by drm/kms driver previously. This is similar to the small patch below: https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ But it's now using the panel API. > > > I think we can also let drm check if they have remote panel nodes: If > > there is a panel and the panel sets the orientation, let the drm read > > this value and set the property. Does this workflow sound reasonable? > > > > The corresponding patch to implement this: > > https://patchwork.kernel.org/project/linux-mediatek/patch/20220530113033.124072-1-hsinyi@chromium.org/ > > That is a suprisingly small patch (which is good). I guess that > my suggestion to add a new panel driver callback to get > the orientation would be a bit bigget then this. Still I think > that that would be a bit cleaner, as it would also solve this > for cases where the orientation comes from the panel itself > (through say some EDID extenstion) rather then from devicetree. > > Still I think either way should be acceptable upstream. > > Opinions from other drm devs on the above are very much welcome! > > Your small patch nicely avoids the probe ordering problem, > so it is much better then this patch series. > > Regards, > > Hans > > > > > > > Thanks > > > >> I see a devicetree patch in this series, so I guess that the panel > >> is described in devicetree. Especially in the case of devicetree > >> I would expect the kernel to have enough info to do the right > >> thing and make sure the panel is probed before calling > >> drm_dev_register() ? > >> > >> Regards, > >> > >> Hans > >> > >> > >> > >> > >>> > >>> After this series, drm_connector_set_panel_orientation() works like > >>> before. It won't affect existing callers of > >>> drm_connector_set_panel_orientation(). The only difference is that > >>> some drm drivers can call drm_connector_init_panel_orientation_property() > >>> earlier. > >>> > >>> Hsin-Yi Wang (4): > >>> gpu: drm: separate panel orientation property creating and value > >>> setting > >>> drm/mediatek: init panel orientation property > >>> drm/msm: init panel orientation property > >>> arm64: dts: mt8183: Add panel rotation > >>> > >>> .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi | 1 + > >>> drivers/gpu/drm/drm_connector.c | 58 ++++++++++++++----- > >>> drivers/gpu/drm/mediatek/mtk_dsi.c | 7 +++ > >>> drivers/gpu/drm/msm/dsi/dsi_manager.c | 4 ++ > >>> include/drm/drm_connector.h | 2 + > >>> 5 files changed, 59 insertions(+), 13 deletions(-) > >>> > >> > > >