diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/soc/amd/common/block/lpc/espi_util.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/src/soc/amd/common/block/lpc/espi_util.c b/src/soc/amd/common/block/lpc/espi_util.c index 276bb3cdc3..c5aac3814a 100644 --- a/src/soc/amd/common/block/lpc/espi_util.c +++ b/src/soc/amd/common/block/lpc/espi_util.c @@ -419,6 +419,7 @@ struct espi_cmd { union espi_txhdr1 hdr1; union espi_txhdr2 hdr2; union espi_txdata data; + uint32_t expected_status_codes; } __packed; /* Wait up to ESPI_CMD_TIMEOUT_US for hardware to clear DNCMD_STATUS bit. */ @@ -512,13 +513,13 @@ static int espi_send_command(const struct espi_cmd *cmd) return -1; } - if (status & ~ESPI_STATUS_DNCMD_COMPLETE) { + if (status & ~(ESPI_STATUS_DNCMD_COMPLETE | cmd->expected_status_codes)) { espi_show_failure(cmd, "Error: unexpected eSPI status register bits set", status); return -1; } - espi_write32(ESPI_SLAVE0_INT_STS, ESPI_STATUS_DNCMD_COMPLETE); + espi_write32(ESPI_SLAVE0_INT_STS, status); return 0; } @@ -530,6 +531,33 @@ static int espi_send_reset(void) .cmd_type = CMD_TYPE_IN_BAND_RESET, .cmd_sts = 1, }, + + /* + * When performing an in-band reset the host controller and the + * peripheral can have mismatched IO configs. + * + * i.e., The eSPI peripheral can be in IO-4 mode while, the + * eSPI host will be in IO-1. This results in the peripheral + * getting invalid packets and thus not responding. + * + * If the peripheral is alerting when we perform an in-band + * reset, there is a race condition in espi_send_command. + * 1) espi_send_command clears the interrupt status. + * 2) eSPI host controller hardware notices the alert and sends + * a GET_STATUS. + * 3) espi_send_command writes the in-band reset command. + * 4) eSPI hardware enqueues the in-band reset until GET_STATUS + * is complete. + * 5) GET_STATUS fails with NO_RESPONSE and sets the interrupt + * status. + * 6) eSPI hardware performs in-band reset. + * 7) espi_send_command checks the status and sees a + * NO_RESPONSE bit. + * + * As a workaround we allow the NO_RESPONSE status code when + * we perform an in-band reset. + */ + .expected_status_codes = ESPI_STATUS_NO_RESPONSE, }; return espi_send_command(&cmd); |