From: "Christian König" <christian.koenig@amd.com> To: Thomas Zimmermann <tzimmermann@suse.de>, daniel@ffwll.ch, airlied@linux.ie, maarten.lankhorst@linux.intel.com, mripard@kernel.org, yuq825@gmail.com, robh@kernel.org, tomeu.vizoso@collabora.com, steven.price@arm.com, alyssa.rosenzweig@collabora.com, eric@anholt.net, sumit.semwal@linaro.org, stern@rowland.harvard.edu Cc: dri-devel@lists.freedesktop.org, lima@lists.freedesktop.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org Subject: Re: [PATCH v2 0/3] drm/prime: Only call dma_map_sgtable() for devices with DMA support Date: Mon, 22 Feb 2021 14:09:03 +0100 [thread overview] Message-ID: <b190801b-b8be-c9df-f203-3e42eb97cea4@amd.com> (raw) In-Reply-To: <20210222124328.27340-1-tzimmermann@suse.de> Am 22.02.21 um 13:43 schrieb Thomas Zimmermann: > USB-based drivers cannot use DMA, so the importing of dma-buf attachments > currently fails for udl and gm12u320. This breaks joining/mirroring of > displays. > > The fix is now a little series. To solve the issue on the importer > side (i.e., the affected USB-based driver), patch 1 introduces a new > PRIME callback, struct drm_driver.gem_prime_create_object, which creates > an object and gives more control to the importing driver. Specifically, > udl and gm12u320 can now avoid the creation of a scatter/gather table > for the imported pages. Patch 1 is self-contained in the sense that it > can be backported into older kernels. Mhm, that sounds like a little overkill to me. Drivers can already import the DMA-bufs all by them selves without the help of the DRM functions. See amdgpu for an example. Daniel also already noted to me that he sees the DRM helper as a bit questionable middle layer. Have you thought about doing that instead? Christian. > > Patches 2 and 3 update SHMEM and CMA helpers to use the new callback. > Effectively this moves the sg table setup from the PRIME helpers into > the memory managers. SHMEM now supports devices without DMA support, > so custom code can be removed from udl and g12u320. > > Tested by joining/mirroring displays of udl and radeon under Gnome/X11. > > v2: > * move fix to importer side (Christian, Daniel) > * update SHMEM and CMA helpers for new PRIME callbacks > > Thomas Zimmermann (3): > drm: Support importing dmabufs into drivers without DMA > drm/shmem-helper: Implement struct drm_driver.gem_prime_create_object > drm/cma-helper: Implement struct drm_driver.gem_prime_create_object > > drivers/gpu/drm/drm_gem_cma_helper.c | 62 ++++++++++++++----------- > drivers/gpu/drm/drm_gem_shmem_helper.c | 38 ++++++++++----- > drivers/gpu/drm/drm_prime.c | 43 +++++++++++------ > drivers/gpu/drm/lima/lima_drv.c | 2 +- > drivers/gpu/drm/panfrost/panfrost_drv.c | 2 +- > drivers/gpu/drm/panfrost/panfrost_gem.c | 6 +-- > drivers/gpu/drm/panfrost/panfrost_gem.h | 4 +- > drivers/gpu/drm/pl111/pl111_drv.c | 8 ++-- > drivers/gpu/drm/v3d/v3d_bo.c | 6 +-- > drivers/gpu/drm/v3d/v3d_drv.c | 2 +- > drivers/gpu/drm/v3d/v3d_drv.h | 5 +- > include/drm/drm_drv.h | 12 +++++ > include/drm/drm_gem_cma_helper.h | 12 ++--- > include/drm/drm_gem_shmem_helper.h | 6 +-- > 14 files changed, 120 insertions(+), 88 deletions(-) > > -- > 2.30.1 >
WARNING: multiple messages have this Message-ID (diff)
From: "Christian König" <christian.koenig@amd.com> To: Thomas Zimmermann <tzimmermann@suse.de>, daniel@ffwll.ch, airlied@linux.ie, maarten.lankhorst@linux.intel.com, mripard@kernel.org, yuq825@gmail.com, robh@kernel.org, tomeu.vizoso@collabora.com, steven.price@arm.com, alyssa.rosenzweig@collabora.com, eric@anholt.net, sumit.semwal@linaro.org, stern@rowland.harvard.edu Cc: linaro-mm-sig@lists.linaro.org, lima@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org Subject: Re: [PATCH v2 0/3] drm/prime: Only call dma_map_sgtable() for devices with DMA support Date: Mon, 22 Feb 2021 14:09:03 +0100 [thread overview] Message-ID: <b190801b-b8be-c9df-f203-3e42eb97cea4@amd.com> (raw) In-Reply-To: <20210222124328.27340-1-tzimmermann@suse.de> Am 22.02.21 um 13:43 schrieb Thomas Zimmermann: > USB-based drivers cannot use DMA, so the importing of dma-buf attachments > currently fails for udl and gm12u320. This breaks joining/mirroring of > displays. > > The fix is now a little series. To solve the issue on the importer > side (i.e., the affected USB-based driver), patch 1 introduces a new > PRIME callback, struct drm_driver.gem_prime_create_object, which creates > an object and gives more control to the importing driver. Specifically, > udl and gm12u320 can now avoid the creation of a scatter/gather table > for the imported pages. Patch 1 is self-contained in the sense that it > can be backported into older kernels. Mhm, that sounds like a little overkill to me. Drivers can already import the DMA-bufs all by them selves without the help of the DRM functions. See amdgpu for an example. Daniel also already noted to me that he sees the DRM helper as a bit questionable middle layer. Have you thought about doing that instead? Christian. > > Patches 2 and 3 update SHMEM and CMA helpers to use the new callback. > Effectively this moves the sg table setup from the PRIME helpers into > the memory managers. SHMEM now supports devices without DMA support, > so custom code can be removed from udl and g12u320. > > Tested by joining/mirroring displays of udl and radeon under Gnome/X11. > > v2: > * move fix to importer side (Christian, Daniel) > * update SHMEM and CMA helpers for new PRIME callbacks > > Thomas Zimmermann (3): > drm: Support importing dmabufs into drivers without DMA > drm/shmem-helper: Implement struct drm_driver.gem_prime_create_object > drm/cma-helper: Implement struct drm_driver.gem_prime_create_object > > drivers/gpu/drm/drm_gem_cma_helper.c | 62 ++++++++++++++----------- > drivers/gpu/drm/drm_gem_shmem_helper.c | 38 ++++++++++----- > drivers/gpu/drm/drm_prime.c | 43 +++++++++++------ > drivers/gpu/drm/lima/lima_drv.c | 2 +- > drivers/gpu/drm/panfrost/panfrost_drv.c | 2 +- > drivers/gpu/drm/panfrost/panfrost_gem.c | 6 +-- > drivers/gpu/drm/panfrost/panfrost_gem.h | 4 +- > drivers/gpu/drm/pl111/pl111_drv.c | 8 ++-- > drivers/gpu/drm/v3d/v3d_bo.c | 6 +-- > drivers/gpu/drm/v3d/v3d_drv.c | 2 +- > drivers/gpu/drm/v3d/v3d_drv.h | 5 +- > include/drm/drm_drv.h | 12 +++++ > include/drm/drm_gem_cma_helper.h | 12 ++--- > include/drm/drm_gem_shmem_helper.h | 6 +-- > 14 files changed, 120 insertions(+), 88 deletions(-) > > -- > 2.30.1 > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2021-02-22 13:12 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-02-22 12:43 [PATCH v2 0/3] drm/prime: Only call dma_map_sgtable() for devices with DMA support Thomas Zimmermann 2021-02-22 12:43 ` Thomas Zimmermann 2021-02-22 12:43 ` [PATCH v2 1/3] drm: Support importing dmabufs into drivers without DMA Thomas Zimmermann 2021-02-22 12:43 ` Thomas Zimmermann 2021-02-22 13:10 ` Ahmed S. Darwish 2021-02-22 13:10 ` Ahmed S. Darwish 2021-02-22 16:31 ` Daniel Vetter 2021-02-22 16:31 ` Daniel Vetter 2021-02-22 12:43 ` [PATCH v2 2/3] drm/shmem-helper: Implement struct drm_driver.gem_prime_create_object Thomas Zimmermann 2021-02-22 12:43 ` Thomas Zimmermann 2021-02-22 12:43 ` [PATCH v2 3/3] drm/cma-helper: " Thomas Zimmermann 2021-02-22 12:43 ` Thomas Zimmermann 2021-02-22 13:09 ` Christian König [this message] 2021-02-22 13:09 ` [PATCH v2 0/3] drm/prime: Only call dma_map_sgtable() for devices with DMA support Christian König 2021-02-22 13:24 ` Thomas Zimmermann 2021-02-22 13:24 ` Thomas Zimmermann 2021-02-22 16:10 ` Daniel Vetter 2021-02-22 16:10 ` Daniel Vetter 2021-02-22 16:25 ` Thomas Zimmermann 2021-02-22 16:25 ` Thomas Zimmermann 2021-02-22 16:34 ` Daniel Vetter 2021-02-22 16:34 ` Daniel Vetter 2021-02-23 8:19 ` Thomas Zimmermann 2021-02-23 8:19 ` Thomas Zimmermann
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