| Message ID | 1449669502-24601-5-git-send-email-m.szyprowski@samsung.com |
|---|---|
| State | New |
| Headers | show |
Hello, On 2015-12-13 20:57, Laurent Pinchart wrote: > Hi Marek, > > Thank you for the patch. > > On Wednesday 09 December 2015 14:58:19 Marek Szyprowski wrote: >> Add a helper function for device drivers to set DMA's max_seg_size. >> Setting it to largest possible value lets DMA-mapping API always create >> contiguous mappings in DMA address space. This is essential for all >> devices, which use dma-contig videobuf2 memory allocator and shared >> buffers. >> >> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> >> --- >> drivers/media/v4l2-core/videobuf2-dma-contig.c | 15 +++++++++++++++ >> include/media/videobuf2-dma-contig.h | 1 + >> 2 files changed, 16 insertions(+) >> >> diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c >> b/drivers/media/v4l2-core/videobuf2-dma-contig.c index c331272..628518d >> 100644 >> --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c >> +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c >> @@ -742,6 +742,21 @@ void vb2_dma_contig_cleanup_ctx(void *alloc_ctx) >> } >> EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx); >> >> +int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size) >> +{ >> + if (!dev->dma_parms) { > When can this function be called with dev->dma_parms not NULL ? When one loads a module with multimedia driver (which calls this function), then unloads and loads it again. It is rather safe to have this check. >> + dev->dma_parms = devm_kzalloc(dev, sizeof(dev->dma_parms), >> + GFP_KERNEL); >> + if (!dev->dma_parms) >> + return -ENOMEM; >> + } >> + if (dma_get_max_seg_size(dev) < size) >> + return dma_set_max_seg_size(dev, size); >> + >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(vb2_dma_contig_set_max_seg_size); >> + >> MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2"); >> MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); >> MODULE_LICENSE("GPL"); >> diff --git a/include/media/videobuf2-dma-contig.h >> b/include/media/videobuf2-dma-contig.h index c33dfa6..0e6ba64 100644 >> --- a/include/media/videobuf2-dma-contig.h >> +++ b/include/media/videobuf2-dma-contig.h >> @@ -26,6 +26,7 @@ vb2_dma_contig_plane_dma_addr(struct vb2_buffer *vb, >> unsigned int plane_no) >> >> void *vb2_dma_contig_init_ctx(struct device *dev); >> void vb2_dma_contig_cleanup_ctx(void *alloc_ctx); >> +int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size); >> >> extern const struct vb2_mem_ops vb2_dma_contig_memops; Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index c331272..628518d 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -742,6 +742,21 @@ void vb2_dma_contig_cleanup_ctx(void *alloc_ctx) } EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx); +int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size) +{ + if (!dev->dma_parms) { + dev->dma_parms = devm_kzalloc(dev, sizeof(dev->dma_parms), + GFP_KERNEL); + if (!dev->dma_parms) + return -ENOMEM; + } + if (dma_get_max_seg_size(dev) < size) + return dma_set_max_seg_size(dev, size); + + return 0; +} +EXPORT_SYMBOL_GPL(vb2_dma_contig_set_max_seg_size); + MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2"); MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); MODULE_LICENSE("GPL"); diff --git a/include/media/videobuf2-dma-contig.h b/include/media/videobuf2-dma-contig.h index c33dfa6..0e6ba64 100644 --- a/include/media/videobuf2-dma-contig.h +++ b/include/media/videobuf2-dma-contig.h @@ -26,6 +26,7 @@ vb2_dma_contig_plane_dma_addr(struct vb2_buffer *vb, unsigned int plane_no) void *vb2_dma_contig_init_ctx(struct device *dev); void vb2_dma_contig_cleanup_ctx(void *alloc_ctx); +int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size); extern const struct vb2_mem_ops vb2_dma_contig_memops;
Add a helper function for device drivers to set DMA's max_seg_size. Setting it to largest possible value lets DMA-mapping API always create contiguous mappings in DMA address space. This is essential for all devices, which use dma-contig videobuf2 memory allocator and shared buffers. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- drivers/media/v4l2-core/videobuf2-dma-contig.c | 15 +++++++++++++++ include/media/videobuf2-dma-contig.h | 1 + 2 files changed, 16 insertions(+) -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html