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From:   xiang xiao <xiaoxiang781216@gmail.com>
Date:   Tue, 15 Jan 2019 14:46:04 +0800
Message-ID: <CAH2Cfb-jgvGWoQ+gim_17bEeg65Kh8=KDDtpe8LZCp=LAr_OLQ@mail.gmail.com>
Subject: Re: [PATCH 1/1] remoteproc: fix recovery procedure
To:     Loic PALLARDY <loic.pallardy@st.com>
Cc:     "bjorn.andersson@linaro.org" <bjorn.andersson@linaro.org>,
        "ohad@wizery.com" <ohad@wizery.com>,
        "linux-remoteproc@vger.kernel.org" <linux-remoteproc@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Arnaud POULIQUEN <arnaud.pouliquen@st.com>,
        "benjamin.gaignard@linaro.org" <benjamin.gaignard@linaro.org>,
        "s-anna@ti.com" <s-anna@ti.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Here is my output after apply your patch, the duplication device still exist:
[   48.012300] remoteproc remoteproc0: crash detected in
f9210000.toppwr:tl421-rproc: type watchdog
[   48.023473] remoteproc remoteproc0: handling crash #1 in
f9210000.toppwr:tl421-rproc
[   48.037504] remoteproc remoteproc0: recovering f9210000.toppwr:tl421-rproc
[   48.048837] remoteproc remoteproc0: stopped remote processor
f9210000.toppwr:tl421-rproc
[   48.061969] virtio_rpmsg_bus virtio2: rpmsg host is online
[   48.061976] virtio_rpmsg_bus virtio2: creating channel rpmsg-ttyADSP addr 0x1
[   48.062956] virtio_rpmsg_bus virtio2: creating channel rpmsg-clk addr 0x2
[   48.063489] virtio_rpmsg_bus virtio2: creating channel rpmsg-syslog addr 0x3
[   48.063815] virtio_rpmsg_bus virtio2: creating channel rpmsg-rtc addr 0x4
[   48.064064] virtio_rpmsg_bus virtio2: creating channel rpmsg-ttyADSP addr 0x1
[   48.064080] virtio_rpmsg_bus virtio2: channel
rpmsg-ttyADSP:ffffffff:1 already exist
[   48.064087] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.064102] virtio_rpmsg_bus virtio2: creating channel rpmsg-ttyADSP addr 0x1
[   48.064118] virtio_rpmsg_bus virtio2: channel
rpmsg-ttyADSP:ffffffff:1 already exist
[   48.064127] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.064139] virtio_rpmsg_bus virtio2: creating channel rpmsg-clk addr 0x2
[   48.064153] virtio_rpmsg_bus virtio2: channel rpmsg-clk:ffffffff:2
already exist
[   48.064159] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.064174] virtio_rpmsg_bus virtio2: creating channel rpmsg-syslog addr 0x3
[   48.064192] virtio_rpmsg_bus virtio2: channel
rpmsg-syslog:ffffffff:3 already exist
[   48.064200] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.064213] virtio_rpmsg_bus virtio2: creating channel rpmsg-rtc addr 0x4
[   48.064229] virtio_rpmsg_bus virtio2: channel rpmsg-rtc:ffffffff:4
already exist
[   48.064235] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.064286] virtio_rpmsg_bus virtio2: creating channel rpmsg-syslog addr 0x3
[   48.064302] virtio_rpmsg_bus virtio2: channel
rpmsg-syslog:ffffffff:3 already exist
[   48.064306] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.064318] virtio_rpmsg_bus virtio2: creating channel rpmsg-rtc addr 0x4
[   48.064334] virtio_rpmsg_bus virtio2: channel rpmsg-rtc:ffffffff:4
already exist
[   48.064339] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.064351] virtio_rpmsg_bus virtio2: creating channel rpmsg-hostfs addr 0x5
[   48.064773] virtio_rpmsg_bus virtio2: creating channel rpmsg-hostfs addr 0x5
[   48.064789] virtio_rpmsg_bus virtio2: channel
rpmsg-hostfs:ffffffff:5 already exist
[   48.064797] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.064930] virtio_rpmsg_bus virtio2: creating channel  addr 0x5f7361
[   48.064945] virtio_rpmsg_bus virtio2: rpmsg_find_device failed
[   48.064957] virtio_rpmsg_bus virtio2: creating channel rpmsg-rtc addr 0x4
[   48.064973] virtio_rpmsg_bus virtio2: channel rpmsg-rtc:ffffffff:4
already exist
[   48.064979] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.065015] virtio_rpmsg_bus virtio2: creating channel rpmsg-hostfs addr 0x5
[   48.065030] virtio_rpmsg_bus virtio2: channel
rpmsg-hostfs:ffffffff:5 already exist
[   48.065035] virtio_rpmsg_bus virtio2: rpmsg_create_channel failed
[   48.352150] remoteproc remoteproc0: registered virtio2 (type 7)
[   48.358813] remoteproc remoteproc0: remote processor
f9210000.toppwr:tl421-rproc is now up
do I still miss any additional patch?

Thanks
Xiang

On Tue, Jan 15, 2019 at 4:23 AM Loic PALLARDY <loic.pallardy@st.com> wrote:
>
> Hi Xiang,
>
> > -----Original Message-----
> > From: xiang xiao <xiaoxiang781216@gmail.com>
> > Sent: samedi 12 janvier 2019 19:29
> > To: Loic PALLARDY <loic.pallardy@st.com>
> > Cc: bjorn.andersson@linaro.org; ohad@wizery.com; linux-
> > remoteproc@vger.kernel.org; linux-kernel@vger.kernel.org; Arnaud
> > POULIQUEN <arnaud.pouliquen@st.com>; benjamin.gaignard@linaro.org; s-
> > anna@ti.com
> > Subject: Re: [PATCH 1/1] remoteproc: fix recovery procedure
> >
> > Hi Loic,
> > The change just hide the problem, I think. The big issue is:
> > 1.virtio devices aren't destroyed by rpproc_stop
> Virtio devices are destroyed by rproc_stop() as vdev is registered as rproc sub device.
> rproc_stop() is calling rproc_stop_subdevices() which is in charge of removing virtio device and associated children.
> rproc_vdev_do_stop() --> rproc_remove_virtio_dev() --> unregister_virtio_device()
>
> Please find below trace of a recovery on my ST SOC. My 2 rpmsg tty are removed and re-inserted correctly
> root@stm32mp1:~# ls /dev/ttyRPMSG*
> /dev/ttyRPMSG0  /dev/ttyRPMSG1
> root@stm32mp1:~# [  154.832523] remoteproc remoteproc0: crash detected in m4: type watchdog
> [  154.837725] remoteproc remoteproc0: handling crash #2 in m4
> [  154.843319] remoteproc remoteproc0: recovering m4
> [  154.849185] rpmsg_tty virtio0.rpmsg-tty-channel.-1.0: rpmsg tty device 0 is removed
> [  154.857572] rpmsg_tty virtio0.rpmsg-tty-channel.-1.1: rpmsg tty device 1 is removed
> [  155.382327] remoteproc remoteproc0: warning: remote FW shutdown without ack
> [  155.387857] remoteproc remoteproc0: stopped remote processor m4
> [  155.398988]  m4@0#vdev0buffer: assigned reserved memory node vdev0buffer@10044000
> [  155.405910] virtio_rpmsg_bus virtio0: creating channel rpmsg-tty-channel addr 0x0
> [  155.413422] rpmsg_tty virtio0.rpmsg-tty-channel.-1.0: new channel: 0x400 -> 0x0 : ttyRPMSG0
> [  155.421038] virtio_rpmsg_bus virtio0: creating channel rpmsg-tty-channel addr 0x1
> [  155.429088] rpmsg_tty virtio0.rpmsg-tty-channel.-1.1: new channel: 0x401 -> 0x1 : ttyRPMSG1
> [  155.437338] virtio_rpmsg_bus virtio0: rpmsg host is online
> [  155.442401]  m4@0#vdev0buffer: registered virtio0 (type 7)
> [  155.461154] remoteproc remoteproc0: remote processor m4 is now up
> ls /dev/ttyRPMSG*
> /dev/ttyRPMSG0  /dev/ttyRPMSG1
> root@stm32mp1:~#
>
> As vdev is including in a larger struct allocated by rproc, it is safe to set it to 0 before initializing virtio device while rproc subdevice sequence is respected.
>
> > 2.and then rpmsg child devices aren't destroyed too
> > Then, when the remote start and create rpmsg channel again, the
> > duplicated channel will appear in kernel.
> > To fix this problem, we need go through rpproc_shutdown/rproc_boot to
> > destroy all devices(virtio and rpmsg) and create them again.
> Rproc_shutdown/rproc_boot is solving the issue too, except if rproc_boot() was called several times and so rproc->power atomic not equal to 1.
> Using only rproc_stop() and rproc_start() allows to preserve rproc->power and so to be silent from rproc user pov.
>
> Regards,
> Loic
> >
> > Thanks
> > Xiang
> >
> > On Wed, Jan 9, 2019 at 6:56 PM Loic Pallardy <loic.pallardy@st.com> wrote:
> > >
> > > Commit 7e83cab824a87e83cab824a8 ("remoteproc: Modify recovery path
> > > to use rproc_{start,stop}()") replaces rproc_{shutdown,boot}() with
> > > rproc_{stop,start}(), which skips destroy the virtio device at stop
> > > but re-initializes it again at start.
> > >
> > > Issue is that struct virtio_dev is not correctly reinitialized like done
> > > at initial allocation thanks to kzalloc() and kobject is considered as
> > > already initialized by kernel. That is due to the fact struct virtio_dev
> > > is allocated and released at vdev resource handling level managed and
> > > virtio device is registered and unregistered at rproc subdevices level.
> > >
> > > This patch initializes struct virtio_dev to 0 before using it and
> > > registering it.
> > >
> > > Fixes: 7e83cab824a8 ("remoteproc: Modify recovery path to use
> > rproc_{start,stop}()")
> > >
> > > Reported-by: Xiang Xiao <xiaoxiang781216@gmail.com>
> > > Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
> > > ---
> > >  drivers/remoteproc/remoteproc_virtio.c | 2 ++
> > >  1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/remoteproc/remoteproc_virtio.c
> > b/drivers/remoteproc/remoteproc_virtio.c
> > > index 183fc42a510a..88eade99395c 100644
> > > --- a/drivers/remoteproc/remoteproc_virtio.c
> > > +++ b/drivers/remoteproc/remoteproc_virtio.c
> > > @@ -332,6 +332,8 @@ int rproc_add_virtio_dev(struct rproc_vdev *rvdev,
> > int id)
> > >         struct virtio_device *vdev = &rvdev->vdev;
> > >         int ret;
> > >
> > > +       /* Reset vdev struct as you don't know how it has been previously
> > used */
> > > +       memset(vdev, 0, sizeof(struct virtio_device));
> > >         vdev->id.device = id,
> > >         vdev->config = &rproc_virtio_config_ops,
> > >         vdev->dev.parent = dev;
> > > --
> > > 2.7.4
> > >