From: Kamlakant Patel kamlakantp@marvell.com

According to ipmi spec, block number is a number that is incremented, starting with 0, for each new block of message data returned using the middle transaction.

Here, the 'blocknum' is data[0] which always starts from zero(0) and 'ssif_info->multi_pos' starts from 1. So, we need to add +1 to blocknum while comparing with multi_pos.

Fixes: 7d6380cd40f79 ("ipmi:ssif: Fix handling of multi-part return messages"). Reported-by: Kiran Kolukuluru kirank@ami.com Signed-off-by: Kamlakant Patel kamlakantp@marvell.com Message-Id: 1556106615-18722-1-git-send-email-kamlakantp@marvell.com [Also added a debug log if the block numbers don't match.] Signed-off-by: Corey Minyard cminyard@mvista.com Cc: stable@vger.kernel.org # 4.4 --- drivers/char/ipmi/ipmi_ssif.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c index 8b5aec5430f1..aaccb0ff1ea6 100644 --- a/drivers/char/ipmi/ipmi_ssif.c +++ b/drivers/char/ipmi/ipmi_ssif.c @@ -727,12 +727,16 @@ static void msg_done_handler(struct ssif_info *ssif_info, int result, /* End of read */ len = ssif_info->multi_len; data = ssif_info->data; - } else if (blocknum != 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, * but multi_pos starts at one, so the +1. */ + if (ssif_info->ssif_debug & SSIF_DEBUG_MSG) + dev_dbg(&ssif_info->client->dev, + "Received message out of sequence, expected %u, got %u\n", + ssif_info->multi_pos - 1, blocknum); result = -EIO; } else { ssif_inc_stat(ssif_info, received_message_parts);