On Sun, Jun 7, 2026 at 4:02 AM Leon Romanovsky leon@kernel.org wrote:
On Thu, Jun 04, 2026 at 03:36:48PM -0400, David Hu wrote:
On Thu, Jun 4, 2026 at 5:43 AM Leon Romanovsky leon@kernel.org wrote:
On Mon, Jun 01, 2026 at 08:00:12PM +0000, David Hu wrote:
@@ -133,6 +137,11 @@ struct sg_table *dma_buf_phys_vec_to_sgt(struct dma_buf_attachment *attach, }
nents = calc_sg_nents(dma->state, phys_vec, nr_ranges, size);
if (!nents) {ret = -EINVAL;goto err_free_state;}Technically, this hunk is not necessary, since sg_alloc_table() will return -EINVAL when nents == 0. At least, that is the behavior I relied on.
I originally added this explicit check in v5 to address Jason's feedback, and to make the failure explicit rather than relying on `sg_alloc_table()` failing silently on `nents=0`.
I prefer explicit checks, but I am not in favor of duplicating them. Since sg_alloc_table() already validates this condition, we do not need to repeat the same check in dma-buf. A comment should be sufficient to inform future reviewers that nents == 0 is already handled.
Thanks
Hi Leon,
Thank you for clarifying this further. Removing the duplication here sounds good to me. I'll drop the hunk, add a comment for posterity noting that `nents = 0` is handled by `sg_alloc_table()`, and send out a v6 shortly.
Thanks a bunch, David