diff options
Diffstat (limited to 'drivers/mfd/cros_ec_spi.c')
-rw-r--r-- | drivers/mfd/cros_ec_spi.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c index 1b52b85..2060d14 100644 --- a/drivers/mfd/cros_ec_spi.c +++ b/drivers/mfd/cros_ec_spi.c @@ -419,10 +419,25 @@ static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev, /* 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; } } @@ -431,7 +446,7 @@ static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev, 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); @@ -537,10 +552,11 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *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; } } @@ -549,7 +565,7 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev, 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); |