ipmi: Fix multi-part message handling

[pandora-kernel.git] / drivers / char / ipmi / ipmi_ssif.c

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 5b82d99..207689c 100644 (file)
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -489,13 +489,13 @@ static int ipmi_ssif_thread(void *data)
 
                if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
                        result = i2c_smbus_write_block_data(
-                               ssif_info->client, SSIF_IPMI_REQUEST,
+                               ssif_info->client, ssif_info->i2c_command,
                                ssif_info->i2c_data[0],
                                ssif_info->i2c_data + 1);
                        ssif_info->done_handler(ssif_info, result, NULL, 0);
                } else {
                        result = i2c_smbus_read_block_data(
-                               ssif_info->client, SSIF_IPMI_RESPONSE,
+                               ssif_info->client, ssif_info->i2c_command,
                                ssif_info->i2c_data);
                        if (result < 0)
                                ssif_info->done_handler(ssif_info, result,
@@ -534,6 +534,7 @@ static void start_get(struct ssif_info *ssif_info)
        int rv;
 
        ssif_info->rtc_us_timer = 0;
+       ssif_info->multi_pos = 0;
 
        rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
                          SSIF_IPMI_RESPONSE,
@@ -631,9 +632,9 @@ static void msg_done_handler(struct ssif_info *ssif_info, int result,
                ssif_inc_stat(ssif_info, received_message_parts);
 
                /* Remove the multi-part read marker. */
-               for (i = 0; i < (len-2); i++)
-                       ssif_info->data[i] = data[i+2];
                len -= 2;
+               for (i = 0; i < len; i++)
+                       ssif_info->data[i] = data[i+2];
                ssif_info->multi_len = len;
                ssif_info->multi_pos = 1;
 
@@ -660,9 +661,9 @@ static void msg_done_handler(struct ssif_info *ssif_info, int result,
                        goto continue_op;
                }
 
-               blocknum = data[ssif_info->multi_len];
+               blocknum = data[0];
 
-               if (ssif_info->multi_len+len-1 > IPMI_MAX_MSG_LENGTH) {
+               if (ssif_info->multi_len + len - 1 > IPMI_MAX_MSG_LENGTH) {
                        /* Received message too big, abort the operation. */
                        result = -E2BIG;
                        if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
@@ -672,15 +673,15 @@ static void msg_done_handler(struct ssif_info *ssif_info, int result,
                }
 
                /* Remove the blocknum from the data. */
-               for (i = 0; i < (len-1); i++)
-                       ssif_info->data[i+ssif_info->multi_len] = data[i+1];
                len--;
+               for (i = 0; i < len; i++)
+                       ssif_info->data[i + ssif_info->multi_len] = data[i + 1];
                ssif_info->multi_len += len;
                if (blocknum == 0xff) {
                        /* End of read */
                        len = ssif_info->multi_len;
                        data = ssif_info->data;
-               } else if ((blocknum+1) != ssif_info->multi_pos) {
+               } else if (blocknum + 1 != ssif_info->multi_pos) {
                        /*
                         * Out of sequence block, just abort.  Block
                         * numbers start at zero for the second block,
@@ -880,7 +881,11 @@ static void msg_written_handler(struct ssif_info *ssif_info, int result,
        }
 
        if (ssif_info->multi_data) {
-               /* In the middle of a multi-data write. */
+               /*
+                * In the middle of a multi-data write.  See the comment
+                * in the SSIF_MULTI_n_PART case in the probe function
+                * for details on the intricacies of this.
+                */
                int left;
 
                ssif_inc_stat(ssif_info, sent_messages_parts);
@@ -984,7 +989,7 @@ static int start_send(struct ssif_info *ssif_info,
                return -E2BIG;
 
        ssif_info->retries_left = SSIF_SEND_RETRIES;
-       memcpy(ssif_info->data+1, data, len);
+       memcpy(ssif_info->data + 1, data, len);
        ssif_info->data_len = len;
        return start_resend(ssif_info);
 }
@@ -1487,13 +1492,33 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
                        break;
 
                case SSIF_MULTI_2_PART:
-                       if (ssif_info->max_xmit_msg_size > 64)
-                               ssif_info->max_xmit_msg_size = 64;
+                       if (ssif_info->max_xmit_msg_size > 63)
+                               ssif_info->max_xmit_msg_size = 63;
                        if (ssif_info->max_recv_msg_size > 62)
                                ssif_info->max_recv_msg_size = 62;
                        break;
 
                case SSIF_MULTI_n_PART:
+                       /*
+                        * The specification is rather confusing at
+                        * this point, but I think I understand what
+                        * is meant.  At least I have a workable
+                        * solution.  With multi-part messages, you
+                        * cannot send a message that is a multiple of
+                        * 32-bytes in length, because the start and
+                        * middle messages are 32-bytes and the end
+                        * message must be at least one byte.  You
+                        * can't fudge on an extra byte, that would
+                        * screw up things like fru data writes.  So
+                        * we limit the length to 63 bytes.  That way
+                        * a 32-byte message gets sent as a single
+                        * part.  A larger message will be a 32-byte
+                        * start and the next message is always going
+                        * to be 1-31 bytes in length.  Not ideal, but
+                        * it should work.
+                        */
+                       if (ssif_info->max_xmit_msg_size > 63)
+                               ssif_info->max_xmit_msg_size = 63;
                        break;
 
                default: