TDES1_BUFFER1_SIZE_MASK
p->des1 |= cpu_to_le32(len & TDES1_BUFFER1_SIZE_MASK);
FIELD_PREP(TDES1_BUFFER1_SIZE_MASK,
p->des1 |= cpu_to_le32(FIELD_PREP(TDES1_BUFFER1_SIZE_MASK,