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Diffstat (limited to 'drivers/fsi/fsi-occ.c')
-rw-r--r--drivers/fsi/fsi-occ.c87
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) {