From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Szyprowski Subject: [PATCH v3 4/7] media: vb2-dma-contig: add helper for setting dma max seg size Date: Wed, 16 Dec 2015 16:37:26 +0100 Message-ID: <1450280249-24681-5-git-send-email-m.szyprowski@samsung.com> References: <1450280249-24681-1-git-send-email-m.szyprowski@samsung.com> Return-path: In-reply-to: <1450280249-24681-1-git-send-email-m.szyprowski@samsung.com> Sender: linux-media-owner@vger.kernel.org To: linux-media@vger.kernel.org, linux-samsung-soc@vger.kernel.org Cc: Marek Szyprowski , devicetree@vger.kernel.org, Sylwester Nawrocki , Kamil Debski , Laurent Pinchart , Andrzej Hajda , Kukjin Kim , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz List-Id: devicetree@vger.kernel.org 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 --- drivers/media/v4l2-core/videobuf2-dma-contig.c | 14 ++++++++++++++ include/media/videobuf2-dma-contig.h | 1 + 2 files changed, 15 insertions(+) diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index c33127284cfe..bd893788d1ae 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -742,6 +742,20 @@ 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 = kzalloc(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 "); MODULE_LICENSE("GPL"); diff --git a/include/media/videobuf2-dma-contig.h b/include/media/videobuf2-dma-contig.h index c33dfa69d7ab..0e6ba644939e 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; -- 1.9.2