iwm_cmd_header
data->scratch_paddr = paddr + sizeof(struct iwm_cmd_header)
struct iwm_cmd_header *cmd_hdr = &pkt->hdr;
((sizeof(struct iwm_cmd_header) + sizeof(*tx)
#define IWM_MAX_CMD_PAYLOAD_SIZE ((4096 - 4) - sizeof(struct iwm_cmd_header))
struct iwm_cmd_header hdr;
sizeof(struct iwm_cmd_header)];
struct iwm_cmd_header hdr;