The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.14.y git checkout FETCH_HEAD git cherry-pick -x 6d2555cde2918409b0331560e66f84a0ad4849c6 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023050640-art-jumbo-6ff0@gregkh' --subject-prefix 'PATCH 4.14.y' HEAD^..

Possible dependencies:

6d2555cde291 ("ipmi: fix SSIF not responding under certain cond.")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6d2555cde2918409b0331560e66f84a0ad4849c6 Mon Sep 17 00:00:00 2001 From: Zhang Yuchen zhangyuchen.lcr@bytedance.com Date: Wed, 12 Apr 2023 15:49:07 +0800 Subject: [PATCH] ipmi: fix SSIF not responding under certain cond.

The ipmi communication is not restored after a specific version of BMC is upgraded on our server. The ipmi driver does not respond after printing the following log:

ipmi_ssif: Invalid response getting flags: 1c 1

I found that after entering this branch, ssif_info->ssif_state always holds SSIF_GETTING_FLAGS and never return to IDLE.

As a result, the driver cannot be loaded, because the driver status is checked during the unload process and must be IDLE in shutdown_ssif():

while (ssif_info->ssif_state != SSIF_IDLE) schedule_timeout(1);

The process trigger this problem is:

1. One msg timeout and next msg start send, and call ssif_set_need_watch().

2. ssif_set_need_watch()->watch_timeout()->start_flag_fetch() change ssif_state to SSIF_GETTING_FLAGS.

3. In msg_done_handler() ssif_state == SSIF_GETTING_FLAGS, if an error message is received, the second branch does not modify the ssif_state.

4. All retry action need IS_SSIF_IDLE() == True. Include retry action in watch_timeout(), msg_done_handler(). Sending msg does not work either. SSIF_IDLE is also checked in start_next_msg().

5. The only thing that can be triggered in the SSIF driver is watch_timeout(), after destory_user(), this timer will stop too.

So, if enter this branch, the ssif_state will remain SSIF_GETTING_FLAGS and can't send msg, no timer started, can't unload.

We did a comparative test before and after adding this patch, and the result is effective.

Fixes: 259307074bfc ("ipmi: Add SMBus interface driver (SSIF)")

Cc: stable@vger.kernel.org Signed-off-by: Zhang Yuchen zhangyuchen.lcr@bytedance.com Message-Id: 20230412074907.80046-1-zhangyuchen.lcr@bytedance.com Signed-off-by: Corey Minyard minyard@acm.org

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c index e4f6ecc12ed7..0eca46eea35c 100644 --- a/drivers/char/ipmi/ipmi_ssif.c +++ b/drivers/char/ipmi/ipmi_ssif.c @@ -786,9 +786,9 @@ static void msg_done_handler(struct ssif_info *ssif_info, int result, } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 || data[1] != IPMI_GET_MSG_FLAGS_CMD) { /* - * Don't abort here, maybe it was a queued - * response to a previous command. + * Recv error response, give up. */ + ssif_info->ssif_state = SSIF_IDLE; ipmi_ssif_unlock_cond(ssif_info, flags); dev_warn(&ssif_info->client->dev, "Invalid response getting flags: %x %x\n",