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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 35283C433B4 for ; Mon, 10 May 2021 19:02:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 165D761139 for ; Mon, 10 May 2021 19:02:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232501AbhEJTDg (ORCPT ); Mon, 10 May 2021 15:03:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229566AbhEJTDa (ORCPT ); Mon, 10 May 2021 15:03:30 -0400 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC608C061574 for ; Mon, 10 May 2021 12:02:24 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id o6-20020a05600c4fc6b029015ec06d5269so3100224wmq.0 for ; Mon, 10 May 2021 12:02:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=h4WHP173ml/IvV38Ii24FlwHTvigSpfq09dlZuPkiS4=; b=kxU/6Cetf8Jp9p1vtNEP21W8Vh9oXZMaTvM3J6yDfbfzwSRb2VaI72nqY2aCpckEHr kze3q4ghadRqOS2+rfuGfWI/felw/cbpuSdTX+EyMAmQIi9jWBwvZCNzzD075oTs8AQP FijOGeDY1+s/umdlSBjaM6PKf6x9endfGo7ov9K5heleejekl7Hv/KjKf2J8K9nykD6N NmsBj3NyLWLsD35hCpthQcXQ1iocnvFBVYhWztGcNYHktiJd5GfEz/MW9sMhLU8jpPdB KbBDFEDfUKJxUpHnXVHTW6+9x2hHsXMFA2fJhLP7OhBCp1MH73KE/oe7DaCpxZwLMi/V YwIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=h4WHP173ml/IvV38Ii24FlwHTvigSpfq09dlZuPkiS4=; b=crzZOhOx21komkaqUxH0M7a9Df9+b4A5RJBHAg4tj2dekeMiPW/GGsjbfwrco8OrQG 68z0kIHOQ7pHNZeVatxTokwQtqUqr2ax5NBfzHdso/19TsCyXiqBD3w0HlwcRoBfeGWC JzWuBM3Xjvj43MCsQApmWUgJ/DCHD6wOcw/vVW6OQgRShCVqX4lk5SCzVyTmtYIzNqzT crf2NctgIZj7s5Pn3eLLpfcq+zqpfVFD/LhjxCsD9BpLIBa687aRW9eoYmqkKjN3+pxr cyVj39ZR1GiTXdeXWWYQZRl7azjxlV6R38+Ygf/Osa35Wq4NSh5SRK5yaeTHdUSwJ3MX osiQ== X-Gm-Message-State: AOAM531hg4ElJHrQsCBJ+wpDVOVFwRlKR2DbOUgwgghQB4ODXDpEvP9H vKR5H3DAkquqyzKOC+pbhHU2BDUYSxKId2Qfj6o= X-Google-Smtp-Source: ABdhPJyedLosMi9DTMI3cZe6mklv8C/MjfcGEGtOrgVxrZtw0BXTtOsdhgOaWKk6a1s7FQ1D+WVIw9GXsgQ9Mw5lmwU= X-Received: by 2002:a7b:c012:: with SMTP id c18mr713621wmb.94.1620673343572; Mon, 10 May 2021 12:02:23 -0700 (PDT) MIME-Version: 1.0 References: <20210508195641.397198-1-robdclark@gmail.com> <20210508195641.397198-2-robdclark@gmail.com> In-Reply-To: From: Rob Clark Date: Mon, 10 May 2021 12:06:05 -0700 Message-ID: Subject: Re: [PATCH 1/2] drm: Fix dirtyfb stalls To: Daniel Vetter Cc: dri-devel , Rob Clark , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , open list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 10, 2021 at 10:44 AM Daniel Vetter wrote: > > On Mon, May 10, 2021 at 6:51 PM Rob Clark wrote: > > > > On Mon, May 10, 2021 at 9:14 AM Daniel Vetter wrote: > > > > > > On Sat, May 08, 2021 at 12:56:38PM -0700, Rob Clark wrote: > > > > From: Rob Clark > > > > > > > > drm_atomic_helper_dirtyfb() will end up stalling for vblank on "video > > > > mode" type displays, which is pointless and unnecessary. Add an > > > > optional helper vfunc to determine if a plane is attached to a CRTC > > > > that actually needs dirtyfb, and skip over them. > > > > > > > > Signed-off-by: Rob Clark > > > > > > So this is a bit annoying because the idea of all these "remap legacy uapi > > > to atomic constructs" helpers is that they shouldn't need/use anything > > > beyond what userspace also has available. So adding hacks for them feels > > > really bad. > > > > I suppose the root problem is that userspace doesn't know if dirtyfb > > (or similar) is actually required or is a no-op. > > > > But it is perhaps less of a problem because this essentially boils > > down to "x11 vs wayland", and it seems like wayland compositors for > > non-vsync'd rendering just pageflips and throws away extra frames from > > the app? > > Yeah it's about not adequately batching up rendering and syncing with > hw. bare metal x11 is just especially stupid about it :-) > > > > Also I feel like it's not entirely the right thing to do here either. > > > We've had this problem already on the fbcon emulation side (which also > > > shouldn't be able to peek behind the atomic kms uapi curtain), and the fix > > > there was to have a worker which batches up all the updates and avoids any > > > stalls in bad places. > > > > I'm not too worried about fbcon not being able to render faster than > > vblank. OTOH it is a pretty big problem for x11 > > That's why we'd let the worker get ahead at most one dirtyfb. We do > the same with fbcon, which trivially can get ahead of vblank otherwise > (if sometimes flushes each character, so you have to pile them up into > a single update if that's still pending). > > > > Since this is for frontbuffer rendering userspace only we can probably get > > > away with assuming there's only a single fb, so the implementation becomes > > > pretty simple: > > > > > > - 1 worker, and we keep track of a single pending fb > > > - if there's already a dirty fb pending on a different fb, we stall for > > > the worker to start processing that one already (i.e. the fb we track is > > > reset to NULL) > > > - if it's pending on the same fb we just toss away all the updates and go > > > with a full update, since merging the clip rects is too much work :-) I > > > think there's helpers so you could be slightly more clever and just have > > > an overall bounding box > > > > This doesn't really fix the problem, you still end up delaying sending > > the next back-buffer to mesa > > With this the dirtyfb would never block. Also glorious frontbuffer > tracking corruption is possible, but that's not the kernel's problem. > So how would anything get held up in userspace. the part about stalling if a dirtyfb is pending was what I was worried about.. but I suppose you meant the worker stalling, rather than userspace stalling (where I had interpreted it the other way around). As soon as userspace needs to stall, you're losing again. > > But we could re-work drm_framebuffer_funcs::dirty to operate on a > > per-crtc basis and hoist the loop and check if dirtyfb is needed out > > of drm_atomic_helper_dirtyfb() > > That's still using information that userspace doesn't have, which is a > bit irky. We might as well go with your thing here then. arguably, this is something we should expose to userspace.. for DSI command-mode panels, you probably want to make a different decision with regard to how many buffers in your flip-chain.. Possibly we should add/remove the fb_damage_clips property depending on the display type (ie. video/pull vs cmd/push mode)? BR, -R > -Daniel > > > BR, > > -R > > > > > > > > Could probably steal most of the implementation. > > > > > > This approach here feels a tad too much in the hacky area ... > > > > > > Thoughts? > > > -Daniel > > > > > > > --- > > > > drivers/gpu/drm/drm_damage_helper.c | 8 ++++++++ > > > > include/drm/drm_modeset_helper_vtables.h | 14 ++++++++++++++ > > > > 2 files changed, 22 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c > > > > index 3a4126dc2520..a0bed1a2c2dc 100644 > > > > --- a/drivers/gpu/drm/drm_damage_helper.c > > > > +++ b/drivers/gpu/drm/drm_damage_helper.c > > > > @@ -211,6 +211,7 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb, > > > > retry: > > > > drm_for_each_plane(plane, fb->dev) { > > > > struct drm_plane_state *plane_state; > > > > + struct drm_crtc *crtc; > > > > > > > > ret = drm_modeset_lock(&plane->mutex, state->acquire_ctx); > > > > if (ret) > > > > @@ -221,6 +222,13 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb, > > > > continue; > > > > } > > > > > > > > + crtc = plane->state->crtc; > > > > + if (crtc->helper_private->needs_dirtyfb && > > > > + !crtc->helper_private->needs_dirtyfb(crtc)) { > > > > + drm_modeset_unlock(&plane->mutex); > > > > + continue; > > > > + } > > > > + > > > > plane_state = drm_atomic_get_plane_state(state, plane); > > > > if (IS_ERR(plane_state)) { > > > > ret = PTR_ERR(plane_state); > > > > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h > > > > index eb706342861d..afa8ec5754e7 100644 > > > > --- a/include/drm/drm_modeset_helper_vtables.h > > > > +++ b/include/drm/drm_modeset_helper_vtables.h > > > > @@ -487,6 +487,20 @@ struct drm_crtc_helper_funcs { > > > > bool in_vblank_irq, int *vpos, int *hpos, > > > > ktime_t *stime, ktime_t *etime, > > > > const struct drm_display_mode *mode); > > > > + > > > > + /** > > > > + * @needs_dirtyfb > > > > + * > > > > + * Optional callback used by damage helpers to determine if fb_damage_clips > > > > + * update is needed. > > > > + * > > > > + * Returns: > > > > + * > > > > + * True if fb_damage_clips update is needed to handle DIRTYFB, False > > > > + * otherwise. If this callback is not implemented, then True is > > > > + * assumed. > > > > + */ > > > > + bool (*needs_dirtyfb)(struct drm_crtc *crtc); > > > > }; > > > > > > > > /** > > > > -- > > > > 2.30.2 > > > > > > > > > > -- > > > Daniel Vetter > > > Software Engineer, Intel Corporation > > > http://blog.ffwll.ch > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch 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=-10.6 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 F1909C433ED for ; Mon, 10 May 2021 19:02:26 +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 A5CB061492 for ; Mon, 10 May 2021 19:02:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A5CB061492 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.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 E709A89F6E; Mon, 10 May 2021 19:02:25 +0000 (UTC) Received: from mail-wm1-x329.google.com (mail-wm1-x329.google.com [IPv6:2a00:1450:4864:20::329]) by gabe.freedesktop.org (Postfix) with ESMTPS id 37F8589F6E for ; Mon, 10 May 2021 19:02:24 +0000 (UTC) Received: by mail-wm1-x329.google.com with SMTP id a10-20020a05600c068ab029014dcda1971aso9636355wmn.3 for ; Mon, 10 May 2021 12:02:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=h4WHP173ml/IvV38Ii24FlwHTvigSpfq09dlZuPkiS4=; b=kxU/6Cetf8Jp9p1vtNEP21W8Vh9oXZMaTvM3J6yDfbfzwSRb2VaI72nqY2aCpckEHr kze3q4ghadRqOS2+rfuGfWI/felw/cbpuSdTX+EyMAmQIi9jWBwvZCNzzD075oTs8AQP FijOGeDY1+s/umdlSBjaM6PKf6x9endfGo7ov9K5heleejekl7Hv/KjKf2J8K9nykD6N NmsBj3NyLWLsD35hCpthQcXQ1iocnvFBVYhWztGcNYHktiJd5GfEz/MW9sMhLU8jpPdB KbBDFEDfUKJxUpHnXVHTW6+9x2hHsXMFA2fJhLP7OhBCp1MH73KE/oe7DaCpxZwLMi/V YwIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=h4WHP173ml/IvV38Ii24FlwHTvigSpfq09dlZuPkiS4=; b=h7xQMCRWOkWI+sQPHloDvR5VlbZYgF4/F/fr0YfX9aGqGCdzaQsWPnoMv3+RAwO+bC 95SD4H5HZtEChfEU+D+7fIgwLlQW9mz74MKRqG9QTMEaSJCP8F7VKmoI7xQEFIUtQQsr TBhEE+VdbQa67qQ1HL8RvAUGfykOTNW88VQlRZejRcNNFhn98uepFqzc2vmsn0vk+R24 M+fU2VdAYT3/6Poqf6WF0ZqmvVF9yiwBLllMeu3ysIPIwgyjLzZT1Cu3XwsjCupUpZUb ZmZC1wkrOonQnIciPeX8RnBKPxf5HrfSXc1qN1bP1I+1oyA3XYzt81YIoKK0SvaAx1uD dxng== X-Gm-Message-State: AOAM533TGEelCkg58HKawV8KpqVpkpiynLNeB1jcaE+zKFN82ob74urI ZlCtXprPdJq2Kiq6QLDDFsLyzLP4/1U7RO7qERW4nBMy X-Google-Smtp-Source: ABdhPJyedLosMi9DTMI3cZe6mklv8C/MjfcGEGtOrgVxrZtw0BXTtOsdhgOaWKk6a1s7FQ1D+WVIw9GXsgQ9Mw5lmwU= X-Received: by 2002:a7b:c012:: with SMTP id c18mr713621wmb.94.1620673343572; Mon, 10 May 2021 12:02:23 -0700 (PDT) MIME-Version: 1.0 References: <20210508195641.397198-1-robdclark@gmail.com> <20210508195641.397198-2-robdclark@gmail.com> In-Reply-To: From: Rob Clark Date: Mon, 10 May 2021 12:06:05 -0700 Message-ID: Subject: Re: [PATCH 1/2] drm: Fix dirtyfb stalls To: Daniel Vetter 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: Rob Clark , David Airlie , open list , dri-devel , Thomas Zimmermann Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, May 10, 2021 at 10:44 AM Daniel Vetter wrote: > > On Mon, May 10, 2021 at 6:51 PM Rob Clark wrote: > > > > On Mon, May 10, 2021 at 9:14 AM Daniel Vetter wrote: > > > > > > On Sat, May 08, 2021 at 12:56:38PM -0700, Rob Clark wrote: > > > > From: Rob Clark > > > > > > > > drm_atomic_helper_dirtyfb() will end up stalling for vblank on "video > > > > mode" type displays, which is pointless and unnecessary. Add an > > > > optional helper vfunc to determine if a plane is attached to a CRTC > > > > that actually needs dirtyfb, and skip over them. > > > > > > > > Signed-off-by: Rob Clark > > > > > > So this is a bit annoying because the idea of all these "remap legacy uapi > > > to atomic constructs" helpers is that they shouldn't need/use anything > > > beyond what userspace also has available. So adding hacks for them feels > > > really bad. > > > > I suppose the root problem is that userspace doesn't know if dirtyfb > > (or similar) is actually required or is a no-op. > > > > But it is perhaps less of a problem because this essentially boils > > down to "x11 vs wayland", and it seems like wayland compositors for > > non-vsync'd rendering just pageflips and throws away extra frames from > > the app? > > Yeah it's about not adequately batching up rendering and syncing with > hw. bare metal x11 is just especially stupid about it :-) > > > > Also I feel like it's not entirely the right thing to do here either. > > > We've had this problem already on the fbcon emulation side (which also > > > shouldn't be able to peek behind the atomic kms uapi curtain), and the fix > > > there was to have a worker which batches up all the updates and avoids any > > > stalls in bad places. > > > > I'm not too worried about fbcon not being able to render faster than > > vblank. OTOH it is a pretty big problem for x11 > > That's why we'd let the worker get ahead at most one dirtyfb. We do > the same with fbcon, which trivially can get ahead of vblank otherwise > (if sometimes flushes each character, so you have to pile them up into > a single update if that's still pending). > > > > Since this is for frontbuffer rendering userspace only we can probably get > > > away with assuming there's only a single fb, so the implementation becomes > > > pretty simple: > > > > > > - 1 worker, and we keep track of a single pending fb > > > - if there's already a dirty fb pending on a different fb, we stall for > > > the worker to start processing that one already (i.e. the fb we track is > > > reset to NULL) > > > - if it's pending on the same fb we just toss away all the updates and go > > > with a full update, since merging the clip rects is too much work :-) I > > > think there's helpers so you could be slightly more clever and just have > > > an overall bounding box > > > > This doesn't really fix the problem, you still end up delaying sending > > the next back-buffer to mesa > > With this the dirtyfb would never block. Also glorious frontbuffer > tracking corruption is possible, but that's not the kernel's problem. > So how would anything get held up in userspace. the part about stalling if a dirtyfb is pending was what I was worried about.. but I suppose you meant the worker stalling, rather than userspace stalling (where I had interpreted it the other way around). As soon as userspace needs to stall, you're losing again. > > But we could re-work drm_framebuffer_funcs::dirty to operate on a > > per-crtc basis and hoist the loop and check if dirtyfb is needed out > > of drm_atomic_helper_dirtyfb() > > That's still using information that userspace doesn't have, which is a > bit irky. We might as well go with your thing here then. arguably, this is something we should expose to userspace.. for DSI command-mode panels, you probably want to make a different decision with regard to how many buffers in your flip-chain.. Possibly we should add/remove the fb_damage_clips property depending on the display type (ie. video/pull vs cmd/push mode)? BR, -R > -Daniel > > > BR, > > -R > > > > > > > > Could probably steal most of the implementation. > > > > > > This approach here feels a tad too much in the hacky area ... > > > > > > Thoughts? > > > -Daniel > > > > > > > --- > > > > drivers/gpu/drm/drm_damage_helper.c | 8 ++++++++ > > > > include/drm/drm_modeset_helper_vtables.h | 14 ++++++++++++++ > > > > 2 files changed, 22 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c > > > > index 3a4126dc2520..a0bed1a2c2dc 100644 > > > > --- a/drivers/gpu/drm/drm_damage_helper.c > > > > +++ b/drivers/gpu/drm/drm_damage_helper.c > > > > @@ -211,6 +211,7 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb, > > > > retry: > > > > drm_for_each_plane(plane, fb->dev) { > > > > struct drm_plane_state *plane_state; > > > > + struct drm_crtc *crtc; > > > > > > > > ret = drm_modeset_lock(&plane->mutex, state->acquire_ctx); > > > > if (ret) > > > > @@ -221,6 +222,13 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb, > > > > continue; > > > > } > > > > > > > > + crtc = plane->state->crtc; > > > > + if (crtc->helper_private->needs_dirtyfb && > > > > + !crtc->helper_private->needs_dirtyfb(crtc)) { > > > > + drm_modeset_unlock(&plane->mutex); > > > > + continue; > > > > + } > > > > + > > > > plane_state = drm_atomic_get_plane_state(state, plane); > > > > if (IS_ERR(plane_state)) { > > > > ret = PTR_ERR(plane_state); > > > > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h > > > > index eb706342861d..afa8ec5754e7 100644 > > > > --- a/include/drm/drm_modeset_helper_vtables.h > > > > +++ b/include/drm/drm_modeset_helper_vtables.h > > > > @@ -487,6 +487,20 @@ struct drm_crtc_helper_funcs { > > > > bool in_vblank_irq, int *vpos, int *hpos, > > > > ktime_t *stime, ktime_t *etime, > > > > const struct drm_display_mode *mode); > > > > + > > > > + /** > > > > + * @needs_dirtyfb > > > > + * > > > > + * Optional callback used by damage helpers to determine if fb_damage_clips > > > > + * update is needed. > > > > + * > > > > + * Returns: > > > > + * > > > > + * True if fb_damage_clips update is needed to handle DIRTYFB, False > > > > + * otherwise. If this callback is not implemented, then True is > > > > + * assumed. > > > > + */ > > > > + bool (*needs_dirtyfb)(struct drm_crtc *crtc); > > > > }; > > > > > > > > /** > > > > -- > > > > 2.30.2 > > > > > > > > > > -- > > > Daniel Vetter > > > Software Engineer, Intel Corporation > > > http://blog.ffwll.ch > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch