On Tue, Jan 29, 2013 at 10:40 PM, Aaron Plattner <aplattner@xxxxxxxxxx> wrote: > On 01/28/2013 05:38 AM, Rahul Sharma wrote: >> >> 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@xxxxxxxxxxx> > > > Reviewed-by: Aaron Plattner <aplattner@xxxxxxxxxx> > > I also verified that this reduces my 2025-entry sg_table to 6 entries, so > > Tested-by: Aaron Plattner <aplattner@xxxxxxxxxx> > > -- > Aaron > Thanks Aaron, I want to request stake-holders to review and test this patch for other platforms. regards, Rahul Sharma. > >> --- >> 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); >> > > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
