The zero value returned from qbman_swp_acquire() is an error condition meaning no free buffer for allocation. Signed-off-by: Ashish Kumar <Ashish.Kumar@nxp.com> Signed-off-by: Kushwaha Prabhakar <prabhakar@freescale.com> [YS: revised commit message] Reviewed-by: York Sun <york.sun@nxp.com>