static int tb_dp_consumed_bandwidth()

in tunnel.c [624:683]

• 44 lines of code
• 9 McCabe index (conditional complexity)

static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
				    int *consumed_down)
{
	struct tb_port *in = tunnel->src_port;
	const struct tb_switch *sw = in->sw;
	u32 val, rate = 0, lanes = 0;
	int ret;

	if (tb_dp_is_usb4(sw)) {
		int timeout = 20;

		/*
		 * Wait for DPRX done. Normally it should be already set
		 * for active tunnel.
		 */
		do {
			ret = tb_port_read(in, &val, TB_CFG_PORT,
					   in->cap_adap + DP_COMMON_CAP, 1);
			if (ret)
				return ret;

			if (val & DP_COMMON_CAP_DPRX_DONE) {
				rate = tb_dp_cap_get_rate(val);
				lanes = tb_dp_cap_get_lanes(val);
				break;
			}
			msleep(250);
		} while (timeout--);

		if (!timeout)
			return -ETIMEDOUT;
	} else if (sw->generation >= 2) {
		/*
		 * Read from the copied remote cap so that we take into
		 * account if capabilities were reduced during exchange.
		 */
		ret = tb_port_read(in, &val, TB_CFG_PORT,
				   in->cap_adap + DP_REMOTE_CAP, 1);
		if (ret)
			return ret;

		rate = tb_dp_cap_get_rate(val);
		lanes = tb_dp_cap_get_lanes(val);
	} else {
		/* No bandwidth management for legacy devices  */
		*consumed_up = 0;
		*consumed_down = 0;
		return 0;
	}

	if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
		*consumed_up = 0;
		*consumed_down = tb_dp_bandwidth(rate, lanes);
	} else {
		*consumed_up = tb_dp_bandwidth(rate, lanes);
		*consumed_down = 0;
	}

	return 0;
}