static int read_copro_response()

in fsi-master-ast-cf.c [377:412]

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

static int read_copro_response(struct fsi_master_acf *master, uint8_t size,
			       uint32_t *response, u8 *tag)
{
	uint8_t rtag = ioread8(master->sram + STAT_RTAG) & 0xf;
	uint8_t rcrc = ioread8(master->sram + STAT_RCRC) & 0xf;
	uint32_t rdata = 0;
	uint32_t crc;
	uint8_t ack;

	*tag = ack = rtag & 3;

	/* we have a whole message now; check CRC */
	crc = crc4(0, 1, 1);
	crc = crc4(crc, rtag, 4);
	if (ack == FSI_RESP_ACK && size) {
		rdata = ioread32be(master->sram + RSP_DATA);
		crc = crc4(crc, rdata, size);
		if (response)
			*response = rdata;
	}
	crc = crc4(crc, rcrc, 4);

	trace_fsi_master_acf_copro_response(master, rtag, rcrc, rdata, crc == 0);

	if (crc) {
		/*
		 * Check if it's all 1's or all 0's, that probably means
		 * the host is off
		 */
		if ((rtag == 0xf && rcrc == 0xf) || (rtag == 0 && rcrc == 0))
			return -ENODEV;
		dev_dbg(master->dev, "Bad response CRC !\n");
		return -EAGAIN;
	}
	return 0;
}