From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Paul Subject: Re: [PATCH v3 5/5] drm: don't block fb changes for async plane updates Date: Tue, 7 May 2019 16:18:19 -0400 Message-ID: <20190507201819.GI17077@art_vandelay> References: <20190314002027.7833-1-helen.koike@collabora.com> <20190314002027.7833-6-helen.koike@collabora.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190314002027.7833-6-helen.koike@collabora.com> Sender: stable-owner@vger.kernel.org To: Helen Koike Cc: dri-devel@lists.freedesktop.org, nicholas.kazlauskas@amd.com, andrey.grodzovsky@amd.com, daniel.vetter@ffwll.ch, linux-kernel@vger.kernel.org, Tomasz Figa , boris.brezillon@collabora.com, David Airlie , Sean Paul , kernel@collabora.com, harry.wentland@amd.com, =?iso-8859-1?Q?St=E9phane?= Marchesin , stable@vger.kernel.org, Sean Paul , Sandy Huang , linux-rockchip@lists.infradead.org, linux-arm-msm@vger.kernel.org, eric@anholt.net, robdclark@gmail.com, amd-gfx@lists.freedesktop.org, Heiko =?iso-8859-1?Q?St=FCbner?= , Maarten Lankhorst , Daniel Vetter , freedreno@lists.freedesktop.org List-Id: linux-arm-msm@vger.kernel.org On Wed, Mar 13, 2019 at 09:20:26PM -0300, Helen Koike wrote: > In the case of a normal sync update, the preparation of framebuffers (be > it calling drm_atomic_helper_prepare_planes() or doing setups with > drm_framebuffer_get()) are performed in the new_state and the respective > cleanups are performed in the old_state. > > In the case of async updates, the preparation is also done in the > new_state but the cleanups are done in the new_state (because updates > are performed in place, i.e. in the current state). > > The current code blocks async udpates when the fb is changed, turning > async updates into sync updates, slowing down cursor updates and > introducing regressions in igt tests with errors of type: > > "CRITICAL: completed 97 cursor updated in a period of 30 flips, we > expect to complete approximately 15360 updates, with the threshold set > at 7680" > > Fb changes in async updates were prevented to avoid the following scenario: > > - Async update, oldfb = NULL, newfb = fb1, prepare fb1, cleanup fb1 > - Async update, oldfb = fb1, newfb = fb2, prepare fb2, cleanup fb2 > - Non-async commit, oldfb = fb2, newfb = fb1, prepare fb1, cleanup fb2 (wrong) > Where we have a single call to prepare fb2 but double cleanup call to fb2. > > To solve the above problems, instead of blocking async fb changes, we > place the old framebuffer in the new_state object, so when the code > performs cleanups in the new_state it will cleanup the old_fb and we > will have the following scenario instead: > > - Async update, oldfb = NULL, newfb = fb1, prepare fb1, no cleanup > - Async update, oldfb = fb1, newfb = fb2, prepare fb2, cleanup fb1 > - Non-async commit, oldfb = fb2, newfb = fb1, prepare fb1, cleanup fb2 > > Where calls to prepare/cleanup are balanced. > > Cc: # v4.14+ I'm not convinced this should be cc: stable, seems more in the improvement category than a bug fix. > Fixes: 25dc194b34dd ("drm: Block fb changes for async plane updates") > Suggested-by: Boris Brezillon > Signed-off-by: Helen Koike > Reviewed-by: Boris Brezillon > Reviewed-by: Nicholas Kazlauskas > > --- > Hello, > > I added a TODO in drm_atomic_helper_async_commit() regarding doing a > full state swap(), Boris and Nicholas, let me know if this is ok and if > I can keep your Reviewed-by tags) > > As mentioned in the cover letter, I tested in almost all platforms with > igt plane_cursor_legacy and kms_cursor_legacy and I didn't see any > regressions. But I couldn't test on MSM and AMD because I don't have > the hardware I would appreciate if anyone could help me testing those. > > Thanks! > Helen > > Changes in v3: > - Add Reviewed-by tags > - Add TODO in drm_atomic_helper_async_commit() > > Changes in v2: > - Change the order of the patch in the series, add this as the last one. > - Add documentation > - s/ballanced/balanced > > drivers/gpu/drm/drm_atomic_helper.c | 22 ++++++++++++---------- > include/drm/drm_modeset_helper_vtables.h | 5 +++++ > 2 files changed, 17 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index 2453678d1186..de5812c362b5 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -1608,15 +1608,6 @@ int drm_atomic_helper_async_check(struct drm_device *dev, > old_plane_state->crtc != new_plane_state->crtc) > return -EINVAL; > > - /* > - * FIXME: Since prepare_fb and cleanup_fb are always called on > - * the new_plane_state for async updates we need to block framebuffer > - * changes. This prevents use of a fb that's been cleaned up and > - * double cleanups from occuring. > - */ > - if (old_plane_state->fb != new_plane_state->fb) > - return -EINVAL; > - > funcs = plane->helper_private; > if (!funcs->atomic_async_update) > return -EINVAL; > @@ -1647,6 +1638,8 @@ EXPORT_SYMBOL(drm_atomic_helper_async_check); > * drm_atomic_async_check() succeeds. Async commits are not supposed to swap > * the states like normal sync commits, but just do in-place changes on the > * current state. > + * > + * TODO: Implement full swap instead of doing in-place changes. > */ > void drm_atomic_helper_async_commit(struct drm_device *dev, > struct drm_atomic_state *state) > @@ -1657,6 +1650,9 @@ void drm_atomic_helper_async_commit(struct drm_device *dev, > int i; > > for_each_new_plane_in_state(state, plane, plane_state, i) { > + struct drm_framebuffer *new_fb = plane_state->fb; > + struct drm_framebuffer *old_fb = plane->state->fb; > + > funcs = plane->helper_private; > funcs->atomic_async_update(plane, plane_state); > > @@ -1665,11 +1661,17 @@ void drm_atomic_helper_async_commit(struct drm_device *dev, > * plane->state in-place, make sure at least common > * properties have been properly updated. > */ > - WARN_ON_ONCE(plane->state->fb != plane_state->fb); > + WARN_ON_ONCE(plane->state->fb != new_fb); > WARN_ON_ONCE(plane->state->crtc_x != plane_state->crtc_x); > WARN_ON_ONCE(plane->state->crtc_y != plane_state->crtc_y); > WARN_ON_ONCE(plane->state->src_x != plane_state->src_x); > WARN_ON_ONCE(plane->state->src_y != plane_state->src_y); > + > + /* > + * Make sure the FBs have been swapped so that cleanups in the > + * new_state performs a cleanup in the old FB. > + */ > + WARN_ON_ONCE(plane_state->fb != old_fb); > } > } > EXPORT_SYMBOL(drm_atomic_helper_async_commit); > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h > index cfb7be40bed7..ce582e8e8f2f 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -1174,6 +1174,11 @@ struct drm_plane_helper_funcs { > * current one with the new plane configurations in the new > * plane_state. > * > + * Drivers should also swap the framebuffers between plane state Perhaps add "current" before plane state and then after add "(&drm_plane.state)" so it's more clear what you're referring to here? > + * and new_state. This is required because prepare and cleanup calls > + * are performed on the new_state object, then to cleanup the old > + * framebuffer, it needs to be placed inside the new_state object. I'd change this bit to: * This is required since cleanup for async commits is performed on * the new state, rather than old state like for traditional commits. * Since we want to give up the reference on the current (old) fb instead * of our brand new one, swap them in the driver during the async commit. > + * > * FIXME: > * - It only works for single plane updates > * - Async Pageflips are not supported yet > -- > 2.20.1 > -- Sean Paul, Software Engineer, Google / Chromium OS 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=-8.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 C0C54C04AAD for ; 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Tue, 07 May 2019 13:18:21 -0700 (PDT) Received: from localhost ([2620:0:1013:11:89c6:2139:5435:371d]) by smtp.gmail.com with ESMTPSA id 3sm2248680qtm.37.2019.05.07.13.18.20 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 07 May 2019 13:18:20 -0700 (PDT) Date: Tue, 7 May 2019 16:18:19 -0400 From: Sean Paul To: Helen Koike Cc: dri-devel@lists.freedesktop.org, nicholas.kazlauskas@amd.com, andrey.grodzovsky@amd.com, daniel.vetter@ffwll.ch, linux-kernel@vger.kernel.org, Tomasz Figa , boris.brezillon@collabora.com, David Airlie , Sean Paul , kernel@collabora.com, harry.wentland@amd.com, =?iso-8859-1?Q?St=E9phane?= Marchesin , stable@vger.kernel.org, Sean Paul , Sandy Huang , linux-rockchip@lists.infradead.org, linux-arm-msm@vger.kernel.org, eric@anholt.net, robdclark@gmail.com, amd-gfx@lists.freedesktop.org, Heiko =?iso-8859-1?Q?St=FCbner?= , Maarten Lankhorst , Daniel Vetter , freedreno@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, Maxime Ripard Subject: Re: [PATCH v3 5/5] drm: don't block fb changes for async plane updates Message-ID: <20190507201819.GI17077@art_vandelay> References: <20190314002027.7833-1-helen.koike@collabora.com> <20190314002027.7833-6-helen.koike@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: <20190314002027.7833-6-helen.koike@collabora.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Message-ID: <20190507201819.RYi9ibd0AYoQuWJiTRSTeJ6sscYXZoDxCQctQkdFERU@z> On Wed, Mar 13, 2019 at 09:20:26PM -0300, Helen Koike wrote: > In the case of a normal sync update, the preparation of framebuffers (be > it calling drm_atomic_helper_prepare_planes() or doing setups with > drm_framebuffer_get()) are performed in the new_state and the respective > cleanups are performed in the old_state. > > In the case of async updates, the preparation is also done in the > new_state but the cleanups are done in the new_state (because updates > are performed in place, i.e. in the current state). > > The current code blocks async udpates when the fb is changed, turning > async updates into sync updates, slowing down cursor updates and > introducing regressions in igt tests with errors of type: > > "CRITICAL: completed 97 cursor updated in a period of 30 flips, we > expect to complete approximately 15360 updates, with the threshold set > at 7680" > > Fb changes in async updates were prevented to avoid the following scenario: > > - Async update, oldfb = NULL, newfb = fb1, prepare fb1, cleanup fb1 > - Async update, oldfb = fb1, newfb = fb2, prepare fb2, cleanup fb2 > - Non-async commit, oldfb = fb2, newfb = fb1, prepare fb1, cleanup fb2 (wrong) > Where we have a single call to prepare fb2 but double cleanup call to fb2. > > To solve the above problems, instead of blocking async fb changes, we > place the old framebuffer in the new_state object, so when the code > performs cleanups in the new_state it will cleanup the old_fb and we > will have the following scenario instead: > > - Async update, oldfb = NULL, newfb = fb1, prepare fb1, no cleanup > - Async update, oldfb = fb1, newfb = fb2, prepare fb2, cleanup fb1 > - Non-async commit, oldfb = fb2, newfb = fb1, prepare fb1, cleanup fb2 > > Where calls to prepare/cleanup are balanced. > > Cc: # v4.14+ I'm not convinced this should be cc: stable, seems more in the improvement category than a bug fix. > Fixes: 25dc194b34dd ("drm: Block fb changes for async plane updates") > Suggested-by: Boris Brezillon > Signed-off-by: Helen Koike > Reviewed-by: Boris Brezillon > Reviewed-by: Nicholas Kazlauskas > > --- > Hello, > > I added a TODO in drm_atomic_helper_async_commit() regarding doing a > full state swap(), Boris and Nicholas, let me know if this is ok and if > I can keep your Reviewed-by tags) > > As mentioned in the cover letter, I tested in almost all platforms with > igt plane_cursor_legacy and kms_cursor_legacy and I didn't see any > regressions. But I couldn't test on MSM and AMD because I don't have > the hardware I would appreciate if anyone could help me testing those. > > Thanks! > Helen > > Changes in v3: > - Add Reviewed-by tags > - Add TODO in drm_atomic_helper_async_commit() > > Changes in v2: > - Change the order of the patch in the series, add this as the last one. > - Add documentation > - s/ballanced/balanced > > drivers/gpu/drm/drm_atomic_helper.c | 22 ++++++++++++---------- > include/drm/drm_modeset_helper_vtables.h | 5 +++++ > 2 files changed, 17 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index 2453678d1186..de5812c362b5 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -1608,15 +1608,6 @@ int drm_atomic_helper_async_check(struct drm_device *dev, > old_plane_state->crtc != new_plane_state->crtc) > return -EINVAL; > > - /* > - * FIXME: Since prepare_fb and cleanup_fb are always called on > - * the new_plane_state for async updates we need to block framebuffer > - * changes. This prevents use of a fb that's been cleaned up and > - * double cleanups from occuring. > - */ > - if (old_plane_state->fb != new_plane_state->fb) > - return -EINVAL; > - > funcs = plane->helper_private; > if (!funcs->atomic_async_update) > return -EINVAL; > @@ -1647,6 +1638,8 @@ EXPORT_SYMBOL(drm_atomic_helper_async_check); > * drm_atomic_async_check() succeeds. Async commits are not supposed to swap > * the states like normal sync commits, but just do in-place changes on the > * current state. > + * > + * TODO: Implement full swap instead of doing in-place changes. > */ > void drm_atomic_helper_async_commit(struct drm_device *dev, > struct drm_atomic_state *state) > @@ -1657,6 +1650,9 @@ void drm_atomic_helper_async_commit(struct drm_device *dev, > int i; > > for_each_new_plane_in_state(state, plane, plane_state, i) { > + struct drm_framebuffer *new_fb = plane_state->fb; > + struct drm_framebuffer *old_fb = plane->state->fb; > + > funcs = plane->helper_private; > funcs->atomic_async_update(plane, plane_state); > > @@ -1665,11 +1661,17 @@ void drm_atomic_helper_async_commit(struct drm_device *dev, > * plane->state in-place, make sure at least common > * properties have been properly updated. > */ > - WARN_ON_ONCE(plane->state->fb != plane_state->fb); > + WARN_ON_ONCE(plane->state->fb != new_fb); > WARN_ON_ONCE(plane->state->crtc_x != plane_state->crtc_x); > WARN_ON_ONCE(plane->state->crtc_y != plane_state->crtc_y); > WARN_ON_ONCE(plane->state->src_x != plane_state->src_x); > WARN_ON_ONCE(plane->state->src_y != plane_state->src_y); > + > + /* > + * Make sure the FBs have been swapped so that cleanups in the > + * new_state performs a cleanup in the old FB. > + */ > + WARN_ON_ONCE(plane_state->fb != old_fb); > } > } > EXPORT_SYMBOL(drm_atomic_helper_async_commit); > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h > index cfb7be40bed7..ce582e8e8f2f 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -1174,6 +1174,11 @@ struct drm_plane_helper_funcs { > * current one with the new plane configurations in the new > * plane_state. > * > + * Drivers should also swap the framebuffers between plane state Perhaps add "current" before plane state and then after add "(&drm_plane.state)" so it's more clear what you're referring to here? > + * and new_state. This is required because prepare and cleanup calls > + * are performed on the new_state object, then to cleanup the old > + * framebuffer, it needs to be placed inside the new_state object. I'd change this bit to: * This is required since cleanup for async commits is performed on * the new state, rather than old state like for traditional commits. * Since we want to give up the reference on the current (old) fb instead * of our brand new one, swap them in the driver during the async commit. > + * > * FIXME: > * - It only works for single plane updates > * - Async Pageflips are not supported yet > -- > 2.20.1 > -- Sean Paul, Software Engineer, Google / Chromium OS 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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_MUTT 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 240A7C004C9 for ; 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Tue, 07 May 2019 13:18:21 -0700 (PDT) Received: from localhost ([2620:0:1013:11:89c6:2139:5435:371d]) by smtp.gmail.com with ESMTPSA id 3sm2248680qtm.37.2019.05.07.13.18.20 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 07 May 2019 13:18:20 -0700 (PDT) Date: Tue, 7 May 2019 16:18:19 -0400 From: Sean Paul To: Helen Koike Subject: Re: [PATCH v3 5/5] drm: don't block fb changes for async plane updates Message-ID: <20190507201819.GI17077@art_vandelay> References: <20190314002027.7833-1-helen.koike@collabora.com> <20190314002027.7833-6-helen.koike@collabora.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190314002027.7833-6-helen.koike@collabora.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190507_131823_273888_1CF72285 X-CRM114-Status: GOOD ( 34.97 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Heiko =?iso-8859-1?Q?St=FCbner?= , Sean Paul , David Airlie , daniel.vetter@ffwll.ch, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, eric@anholt.net, kernel@collabora.com, Maxime Ripard , amd-gfx@lists.freedesktop.org, linux-rockchip@lists.infradead.org, harry.wentland@amd.com, andrey.grodzovsky@amd.com, linux-arm-msm@vger.kernel.org, Maarten Lankhorst , Sean Paul , linux-arm-kernel@lists.infradead.org, =?iso-8859-1?Q?St=E9phane?= Marchesin , Sandy Huang , stable@vger.kernel.org, Tomasz Figa , robdclark@gmail.com, boris.brezillon@collabora.com, Daniel Vetter , freedreno@lists.freedesktop.org, nicholas.kazlauskas@amd.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Mar 13, 2019 at 09:20:26PM -0300, Helen Koike wrote: > In the case of a normal sync update, the preparation of framebuffers (be > it calling drm_atomic_helper_prepare_planes() or doing setups with > drm_framebuffer_get()) are performed in the new_state and the respective > cleanups are performed in the old_state. > > In the case of async updates, the preparation is also done in the > new_state but the cleanups are done in the new_state (because updates > are performed in place, i.e. in the current state). > > The current code blocks async udpates when the fb is changed, turning > async updates into sync updates, slowing down cursor updates and > introducing regressions in igt tests with errors of type: > > "CRITICAL: completed 97 cursor updated in a period of 30 flips, we > expect to complete approximately 15360 updates, with the threshold set > at 7680" > > Fb changes in async updates were prevented to avoid the following scenario: > > - Async update, oldfb = NULL, newfb = fb1, prepare fb1, cleanup fb1 > - Async update, oldfb = fb1, newfb = fb2, prepare fb2, cleanup fb2 > - Non-async commit, oldfb = fb2, newfb = fb1, prepare fb1, cleanup fb2 (wrong) > Where we have a single call to prepare fb2 but double cleanup call to fb2. > > To solve the above problems, instead of blocking async fb changes, we > place the old framebuffer in the new_state object, so when the code > performs cleanups in the new_state it will cleanup the old_fb and we > will have the following scenario instead: > > - Async update, oldfb = NULL, newfb = fb1, prepare fb1, no cleanup > - Async update, oldfb = fb1, newfb = fb2, prepare fb2, cleanup fb1 > - Non-async commit, oldfb = fb2, newfb = fb1, prepare fb1, cleanup fb2 > > Where calls to prepare/cleanup are balanced. > > Cc: # v4.14+ I'm not convinced this should be cc: stable, seems more in the improvement category than a bug fix. > Fixes: 25dc194b34dd ("drm: Block fb changes for async plane updates") > Suggested-by: Boris Brezillon > Signed-off-by: Helen Koike > Reviewed-by: Boris Brezillon > Reviewed-by: Nicholas Kazlauskas > > --- > Hello, > > I added a TODO in drm_atomic_helper_async_commit() regarding doing a > full state swap(), Boris and Nicholas, let me know if this is ok and if > I can keep your Reviewed-by tags) > > As mentioned in the cover letter, I tested in almost all platforms with > igt plane_cursor_legacy and kms_cursor_legacy and I didn't see any > regressions. But I couldn't test on MSM and AMD because I don't have > the hardware I would appreciate if anyone could help me testing those. > > Thanks! > Helen > > Changes in v3: > - Add Reviewed-by tags > - Add TODO in drm_atomic_helper_async_commit() > > Changes in v2: > - Change the order of the patch in the series, add this as the last one. > - Add documentation > - s/ballanced/balanced > > drivers/gpu/drm/drm_atomic_helper.c | 22 ++++++++++++---------- > include/drm/drm_modeset_helper_vtables.h | 5 +++++ > 2 files changed, 17 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index 2453678d1186..de5812c362b5 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -1608,15 +1608,6 @@ int drm_atomic_helper_async_check(struct drm_device *dev, > old_plane_state->crtc != new_plane_state->crtc) > return -EINVAL; > > - /* > - * FIXME: Since prepare_fb and cleanup_fb are always called on > - * the new_plane_state for async updates we need to block framebuffer > - * changes. This prevents use of a fb that's been cleaned up and > - * double cleanups from occuring. > - */ > - if (old_plane_state->fb != new_plane_state->fb) > - return -EINVAL; > - > funcs = plane->helper_private; > if (!funcs->atomic_async_update) > return -EINVAL; > @@ -1647,6 +1638,8 @@ EXPORT_SYMBOL(drm_atomic_helper_async_check); > * drm_atomic_async_check() succeeds. Async commits are not supposed to swap > * the states like normal sync commits, but just do in-place changes on the > * current state. > + * > + * TODO: Implement full swap instead of doing in-place changes. > */ > void drm_atomic_helper_async_commit(struct drm_device *dev, > struct drm_atomic_state *state) > @@ -1657,6 +1650,9 @@ void drm_atomic_helper_async_commit(struct drm_device *dev, > int i; > > for_each_new_plane_in_state(state, plane, plane_state, i) { > + struct drm_framebuffer *new_fb = plane_state->fb; > + struct drm_framebuffer *old_fb = plane->state->fb; > + > funcs = plane->helper_private; > funcs->atomic_async_update(plane, plane_state); > > @@ -1665,11 +1661,17 @@ void drm_atomic_helper_async_commit(struct drm_device *dev, > * plane->state in-place, make sure at least common > * properties have been properly updated. > */ > - WARN_ON_ONCE(plane->state->fb != plane_state->fb); > + WARN_ON_ONCE(plane->state->fb != new_fb); > WARN_ON_ONCE(plane->state->crtc_x != plane_state->crtc_x); > WARN_ON_ONCE(plane->state->crtc_y != plane_state->crtc_y); > WARN_ON_ONCE(plane->state->src_x != plane_state->src_x); > WARN_ON_ONCE(plane->state->src_y != plane_state->src_y); > + > + /* > + * Make sure the FBs have been swapped so that cleanups in the > + * new_state performs a cleanup in the old FB. > + */ > + WARN_ON_ONCE(plane_state->fb != old_fb); > } > } > EXPORT_SYMBOL(drm_atomic_helper_async_commit); > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h > index cfb7be40bed7..ce582e8e8f2f 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -1174,6 +1174,11 @@ struct drm_plane_helper_funcs { > * current one with the new plane configurations in the new > * plane_state. > * > + * Drivers should also swap the framebuffers between plane state Perhaps add "current" before plane state and then after add "(&drm_plane.state)" so it's more clear what you're referring to here? > + * and new_state. This is required because prepare and cleanup calls > + * are performed on the new_state object, then to cleanup the old > + * framebuffer, it needs to be placed inside the new_state object. I'd change this bit to: * This is required since cleanup for async commits is performed on * the new state, rather than old state like for traditional commits. * Since we want to give up the reference on the current (old) fb instead * of our brand new one, swap them in the driver during the async commit. > + * > * FIXME: > * - It only works for single plane updates > * - Async Pageflips are not supported yet > -- > 2.20.1 > -- Sean Paul, Software Engineer, Google / Chromium OS _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel