It fixes the issue arises due to passing 'nr_pages' in place of 'nents' to sg_alloc_table. When ARM_HAS_SG_CHAIN is disabled, it is causing failure in creating SG table for the buffers having more than 204 physical pages i.e. equal to SG_MAX_SINGLE_ALLOC.
When using sg_alloc_table_from_pages interface, in place of sg_alloc_table, page list will be passes to get each contiguous section which is represented by a single entry in the table. For a Contiguous Buffer, number of entries should be equal to 1.
Following check is causing the failure which is not applicable for Non-Contig buffers:
if (WARN_ON_ONCE(nents > max_ents)) return -EINVAL;
Above patch is well tested for EXYNOS4 and EXYNOS5 for with/wihtout IOMMU supprot. NOUVEAU and RADEON platforms also depends on drm_prime_pages_to_sg helper function.
This set is base on "exynos-drm-fixes" branch at http://git.kernel.org/?p=linux/kernel/git/daeinki/drm-exynos.git
Signed-off-by: Rahul Sharma rahul.sharma@samsung.com --- drivers/gpu/drm/drm_prime.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 7f12573..072ee08 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -217,21 +217,17 @@ int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data, struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages) { struct sg_table *sg = NULL; - struct scatterlist *iter; - int i; int ret;
sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL); if (!sg) goto out;
- ret = sg_alloc_table(sg, nr_pages, GFP_KERNEL); + ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0, + nr_pages << PAGE_SHIFT, GFP_KERNEL); if (ret) goto out;
- for_each_sg(sg->sgl, iter, nr_pages, i) - sg_set_page(iter, pages[i], PAGE_SIZE, 0); - return sg; out: kfree(sg);