/* Verify that EC can process command */
for (i = 0; i < len; i++) {
rx_byte = rx_buf[i];
+ /*
+ * Seeing the PAST_END, RX_BAD_DATA, or NOT_READY
+ * markers are all signs that the EC didn't fully
+ * receive our command. e.g., if the EC is flashing
+ * itself, it can't respond to any commands and instead
+ * clocks out EC_SPI_PAST_END from its SPI hardware
+ * buffer. Similar occurrences can happen if the AP is
+ * too slow to clock out data after asserting CS -- the
+ * EC will abort and fill its buffer with
+ * EC_SPI_RX_BAD_DATA.
+ *
+ * In all cases, these errors should be safe to retry.
+ * Report -EAGAIN and let the caller decide what to do
+ * about that.
+ */
if (rx_byte == EC_SPI_PAST_END ||
rx_byte == EC_SPI_RX_BAD_DATA ||
rx_byte == EC_SPI_NOT_READY) {
- ret = -EREMOTEIO;
+ ret = -EAGAIN;
break;
}
}
if (!ret)
ret = cros_ec_spi_receive_packet(ec_dev,
ec_msg->insize + sizeof(*response));
- else
+ else if (ret != -EAGAIN)
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
final_ret = terminate_request(ec_dev);
/* Verify that EC can process command */
for (i = 0; i < len; i++) {
rx_byte = rx_buf[i];
+ /* See comments in cros_ec_pkt_xfer_spi() */
if (rx_byte == EC_SPI_PAST_END ||
rx_byte == EC_SPI_RX_BAD_DATA ||
rx_byte == EC_SPI_NOT_READY) {
- ret = -EREMOTEIO;
+ ret = -EAGAIN;
break;
}
}
if (!ret)
ret = cros_ec_spi_receive_response(ec_dev,
ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
- else
+ else if (ret != -EAGAIN)
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
final_ret = terminate_request(ec_dev);