Messages in this thread | | | Date | Wed, 12 Apr 2023 07:34:49 -0500 | From | Corey Minyard <> | Subject | Re: [PATCH] ipmi: fix SSIF not responding under certain cond. |
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On Wed, Apr 12, 2023 at 03:49:07PM +0800, Zhang Yuchen wrote: > 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:
Excellent explaination, this is queued in my branch for the next release and marked for backport.
Thank you,
-corey
> > 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)") > > Signed-off-by: Zhang Yuchen <zhangyuchen.lcr@bytedance.com> > --- > drivers/char/ipmi/ipmi_ssif.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c > index a5ddebb1edea..48be3694fa64 100644 > --- a/drivers/char/ipmi/ipmi_ssif.c > +++ b/drivers/char/ipmi/ipmi_ssif.c > @@ -784,9 +784,9 @@ 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", > -- > 2.20.1 >
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