| Message ID | 20250613090431.127087-1-tzimmermann@suse.de |
|---|---|
| Headers | show |
| Series | drm/dumb-buffers: Fix and improve buffer-size calculation | expand |
Hi Thomas, Thank you for the patch. On Fri, Jun 13, 2025 at 11:00:44AM +0200, Thomas Zimmermann wrote: > Call drm_mode_size_dumb() to compute dumb-buffer scanline pitch and > buffer size. Align the pitch according to hardware requirements. > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> > Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > drivers/gpu/drm/xlnx/zynqmp_kms.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/xlnx/zynqmp_kms.c b/drivers/gpu/drm/xlnx/zynqmp_kms.c > index b47463473472..7ea0cd4f71d3 100644 > --- a/drivers/gpu/drm/xlnx/zynqmp_kms.c > +++ b/drivers/gpu/drm/xlnx/zynqmp_kms.c > @@ -19,6 +19,7 @@ > #include <drm/drm_crtc.h> > #include <drm/drm_device.h> > #include <drm/drm_drv.h> > +#include <drm/drm_dumb_buffers.h> > #include <drm/drm_encoder.h> > #include <drm/drm_fbdev_dma.h> > #include <drm/drm_fourcc.h> > @@ -363,10 +364,12 @@ static int zynqmp_dpsub_dumb_create(struct drm_file *file_priv, > struct drm_mode_create_dumb *args) > { > struct zynqmp_dpsub *dpsub = to_zynqmp_dpsub(drm); > - unsigned int pitch = DIV_ROUND_UP(args->width * args->bpp, 8); > + int ret; > > /* Enforce the alignment constraints of the DMA engine. */ > - args->pitch = ALIGN(pitch, dpsub->dma_align); > + ret = drm_mode_size_dumb(drm, args, dpsub->dma_align, 0); > + if (ret) > + return ret; > > return drm_gem_dma_dumb_create_internal(file_priv, drm, args); > }
Dumb-buffer pitch and size is specified by width, height, bits-per-pixel plus various hardware-specific alignments. The calculation of these values is inconsistent and duplicated among drivers. The results for formats with bpp < 8 are sometimes incorrect. This series fixes this for most drivers. Default scanline pitch and buffer size are now calculated with the existing 4CC helpers. There is a new helper drm_mode_size_dumb() that calculates scanline pitch and buffer size according to driver requirements. The series fixes the common GEM implementations for DMA, SHMEM and VRAM. It further changes most implementations of dumb_create to use the new helper. A small number of drivers has more complicated calculations and will be updated by a later patches. v5: - use check_mul_overflow() for overflow test (Tomi) - imx: fix intermediate code (Tomi) - rz-du: include dumb-buffers header v4: - improve UAPI documentation - document bpp special cases - use drm_warn_once() - add TODO lists - armada: fix pitch alignment v3: - document UAPI semantics - fall back to bpp-based allocation for unknown color modes - cleanups v2: - rewrite series - convert many individual drivers besides the shared GEM helpers Thomas Zimmermann (25): drm/dumb-buffers: Sanitize output on errors drm/dumb-buffers: Provide helper to set pitch and size drm/gem-dma: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/gem-shmem: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/gem-vram: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/armada: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/exynos: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/gma500: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/hibmc: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/imx/ipuv3: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/loongson: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/mediatek: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/msm: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/nouveau: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/omapdrm: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/qxl: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/renesas/rcar-du: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/renesas/rz-du: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/rockchip: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/tegra: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/virtio: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/vmwgfx: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/xe: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/xen: Compute dumb-buffer sizes with drm_mode_size_dumb() drm/xlnx: Compute dumb-buffer sizes with drm_mode_size_dumb() Documentation/gpu/todo.rst | 27 +++ drivers/gpu/drm/armada/armada_gem.c | 16 +- drivers/gpu/drm/drm_dumb_buffers.c | 170 ++++++++++++++++-- drivers/gpu/drm/drm_gem_dma_helper.c | 7 +- drivers/gpu/drm/drm_gem_shmem_helper.c | 16 +- drivers/gpu/drm/drm_gem_vram_helper.c | 89 +++------ drivers/gpu/drm/exynos/exynos_drm_gem.c | 8 +- drivers/gpu/drm/gma500/gem.c | 21 +-- .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 25 ++- drivers/gpu/drm/imx/ipuv3/imx-drm-core.c | 29 ++- drivers/gpu/drm/loongson/lsdc_gem.c | 29 +-- drivers/gpu/drm/mediatek/mtk_gem.c | 13 +- drivers/gpu/drm/msm/msm_gem.c | 27 ++- drivers/gpu/drm/nouveau/nouveau_display.c | 7 +- drivers/gpu/drm/omapdrm/omap_gem.c | 15 +- drivers/gpu/drm/qxl/qxl_dumb.c | 17 +- drivers/gpu/drm/renesas/rcar-du/rcar_du_kms.c | 7 +- drivers/gpu/drm/renesas/rz-du/rzg2l_du_kms.c | 8 +- drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 12 +- drivers/gpu/drm/tegra/gem.c | 8 +- drivers/gpu/drm/virtio/virtgpu_gem.c | 11 +- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 21 +-- drivers/gpu/drm/xe/xe_bo.c | 8 +- drivers/gpu/drm/xen/xen_drm_front.c | 7 +- drivers/gpu/drm/xlnx/zynqmp_kms.c | 7 +- include/drm/drm_dumb_buffers.h | 14 ++ include/drm/drm_gem_vram_helper.h | 6 - include/uapi/drm/drm_mode.h | 50 +++++- 28 files changed, 447 insertions(+), 228 deletions(-) create mode 100644 include/drm/drm_dumb_buffers.h base-commit: 75238c32deae15ee4120b42a5be556ec36807a84 prerequisite-patch-id: c67e5d886a47b7d0266d81100837557fda34cb24 prerequisite-patch-id: a5a973e527c88a5b47053d7a72aefe0b550197cb prerequisite-patch-id: 719d09751d38f5da743beed6266585ee063e1e29