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| author | Zhang Yuchen <zhangyuchen.lcr@bytedance.com> | 2023-04-12 09:49:07 +0200 |
|---|---|---|
| committer | Corey Minyard <minyard@acm.org> | 2023-04-12 14:33:34 +0200 |
| commit | 6d2555cde2918409b0331560e66f84a0ad4849c6 (patch) | |
| tree | f30b51bb824c4514d9438168fa1b0b1b51bc1e6f /drivers/char | |
| parent | ipmi:ssif: Add send_retries increment (diff) | |
| download | linux-6d2555cde2918409b0331560e66f84a0ad4849c6.tar.xz linux-6d2555cde2918409b0331560e66f84a0ad4849c6.zip | |
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>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/ipmi/ipmi_ssif.c | 4 |
1 files changed, 2 insertions, 2 deletions
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", |