Date: Thu, 5 Jan 2012 20:41:38 +0530 From: "Desai, Kashyap" <Kashyap.Desai@lsi.com> To: "scsi@freebsd.org" <scsi@freebsd.org>, "Kenneth D. Merry" <ken@FreeBSD.org> Cc: "gibbs@FreeBSD.org" <gibbs@FreeBSD.org>, "McConnell, Stephen" <Stephen.McConnell@lsi.com> Subject: kldunload hangs on FreeBSD with camcontrol debug on Message-ID: <B2FD678A64EAAD45B089B123FDFC3ED7299CF90945@inbmail01.lsi.com>
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While doing some sanity test on "mps" driver, I found kldunload hangs in be=
low condition.
Case-1
1. Connect LSI 2008 controller(any SAS2 card). Load there mps driver and de=
tect the controller.
2. unload driver/load driver in loop. There will not be any problem.
Case-2=20
Run above Case-1 with below settings.
"camcontorl debug -IT <bus>"
A moment I enable CAM debug level -I and -T, kldunload always hangs on "sim=
->refcount"
Here is relavent output for reference.
Jan 5 06:42:08 dhcp-135-24-192-146 kernel: mpslsi30: mps_detach_sas:754 re=
f count 2
Jan 5 06:42:08 dhcp-135-24-192-146 kernel: mpslsi30: path ID 6
Jan 5 06:42:08 dhcp-135-24-192-146 kernel: (noperiph:mpslsi30:0:-1:-1): xp=
t_compile_path
Jan 5 06:42:08 dhcp-135-24-192-146 kernel: (noperiph:mpslsi30:0:-1:-1): xp=
t_async
Jan 5 06:42:08 dhcp-135-24-192-146 kernel: (noperiph:mpslsi30:0:-1:-1): xp=
t_async
Jan 5 06:42:08 dhcp-135-24-192-146 kernel: (noperiph:mpslsi30:0:-1:-1): xp=
t_release_path
Jan 5 06:42:08 dhcp-135-24-192-146 kernel: mpslsi30: mps_detach_sas:757 re=
f count 2
I have added few prints in detach routine (mps_detach_sas) as below.
if (sassc->sim !=3D NULL) {
mps_dprint(sc, MPS_INFO, "%s:%d ref count %d\n", __func__,__LINE__,=
sassc->sim->refcount);
mps_dprint(sc, MPS_INFO, "path ID %d\n",cam_sim_path(sassc->sim));
xpt_bus_deregister(cam_sim_path(sassc->sim));
mps_dprint(sc, MPS_INFO, "%s:%d ref count %d\n", __func__,__LINE__,=
sassc->sim->refcount);
cam_sim_free(sassc->sim, FALSE);
}
Before entering into " xpt_bus_deregister" sim->refcount is 2 and which nev=
er goes to 0. And eventually Driver unloading hangs at
Cam_sim_free() at below location....
error =3D msleep(sim, sim->mtx, PRIBIO, "simfree", 0);
Any idea about this issue ?
Regards, Kashyap
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