diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/fsi/fsi-occ.c | 87 |
1 files changed, 56 insertions, 31 deletions
diff --git a/drivers/fsi/fsi-occ.c b/drivers/fsi/fsi-occ.c index 7eaab1be0aa4..c9cc75fbdfb9 100644 --- a/drivers/fsi/fsi-occ.c +++ b/drivers/fsi/fsi-occ.c @@ -451,6 +451,14 @@ static int occ_trigger_attn(struct occ *occ) return rc; } +static bool fsi_occ_response_not_ready(struct occ_response *resp, u8 seq_no, + u8 cmd_type) +{ + return resp->return_status == OCC_RESP_CMD_IN_PRG || + resp->return_status == OCC_RESP_CRIT_INIT || + resp->seq_no != seq_no || resp->cmd_type != cmd_type; +} + int fsi_occ_submit(struct device *dev, const void *request, size_t req_len, void *response, size_t *resp_len) { @@ -461,10 +469,11 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len, struct occ_response *resp = response; size_t user_resp_len = *resp_len; u8 seq_no; + u8 cmd_type; u16 checksum = 0; u16 resp_data_length; const u8 *byte_request = (const u8 *)request; - unsigned long start; + unsigned long end; int rc; size_t i; @@ -478,6 +487,8 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len, return -EINVAL; } + cmd_type = byte_request[1]; + /* Checksum the request, ignoring first byte (sequence number). */ for (i = 1; i < req_len - 2; ++i) checksum += byte_request[i]; @@ -509,51 +520,61 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len, if (rc) goto done; - /* Read occ response header */ - start = jiffies; - do { + end = jiffies + timeout; + while (true) { + /* Read occ response header */ rc = occ_getsram(occ, 0, resp, 8); if (rc) goto done; - if (resp->return_status == OCC_RESP_CMD_IN_PRG || - resp->return_status == OCC_RESP_CRIT_INIT || - resp->seq_no != seq_no) { - rc = -ETIMEDOUT; - - if (time_after(jiffies, start + timeout)) { - dev_err(occ->dev, "resp timeout status=%02x " - "resp seq_no=%d our seq_no=%d\n", + if (fsi_occ_response_not_ready(resp, seq_no, cmd_type)) { + if (time_after(jiffies, end)) { + dev_err(occ->dev, + "resp timeout status=%02x seq=%d cmd=%d, our seq=%d cmd=%d\n", resp->return_status, resp->seq_no, - seq_no); + resp->cmd_type, seq_no, cmd_type); + rc = -ETIMEDOUT; goto done; } set_current_state(TASK_UNINTERRUPTIBLE); schedule_timeout(wait_time); - } - } while (rc); - - /* Extract size of response data */ - resp_data_length = get_unaligned_be16(&resp->data_length); + } else { + /* Extract size of response data */ + resp_data_length = + get_unaligned_be16(&resp->data_length); + + /* + * Message size is data length + 5 bytes header + 2 + * bytes checksum + */ + if ((resp_data_length + 7) > user_resp_len) { + rc = -EMSGSIZE; + goto done; + } - /* Message size is data length + 5 bytes header + 2 bytes checksum */ - if ((resp_data_length + 7) > user_resp_len) { - rc = -EMSGSIZE; - goto done; + /* + * Get the entire response including the header again, + * in case it changed + */ + if (resp_data_length > 1) { + rc = occ_getsram(occ, 0, resp, + resp_data_length + 7); + if (rc) + goto done; + + if (!fsi_occ_response_not_ready(resp, seq_no, + cmd_type)) + break; + } else { + break; + } + } } dev_dbg(dev, "resp_status=%02x resp_data_len=%d\n", resp->return_status, resp_data_length); - /* Grab the rest */ - if (resp_data_length > 1) { - /* already got 3 bytes resp, also need 2 bytes checksum */ - rc = occ_getsram(occ, 8, &resp->data[3], resp_data_length - 1); - if (rc) - goto done; - } - occ->client_response_size = resp_data_length + 7; rc = occ_verify_checksum(occ, resp, resp_data_length); @@ -598,7 +619,11 @@ static int occ_probe(struct platform_device *pdev) occ->version = (uintptr_t)of_device_get_match_data(dev); occ->dev = dev; occ->sbefifo = dev->parent; - occ->sequence_number = 1; + /* + * Quickly derive a pseudo-random number from jiffies so that + * re-probing the driver doesn't accidentally overlap sequence numbers. + */ + occ->sequence_number = (u8)((jiffies % 0xff) + 1); mutex_init(&occ->occ_lock); if (dev->of_node) { |