RE: [PATCH 1/1] remoteproc: fix recovery procedure

[Loic PALLARDY]

Hi Xiang,

> -----Original Message-----
> From: linux-remoteproc-owner@xxxxxxxxxxxxxxx <linux-remoteproc-
> owner@xxxxxxxxxxxxxxx> On Behalf Of xiang xiao
> Sent: mardi 15 janvier 2019 07:46
> To: Loic PALLARDY <loic.pallardy@xxxxxx>
> Cc: bjorn.andersson@xxxxxxxxxx; ohad@xxxxxxxxxx; linux-
> remoteproc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Arnaud
> POULIQUEN <arnaud.pouliquen@xxxxxx>; benjamin.gaignard@xxxxxxxxxx; s-
> anna@xxxxxx
> Subject: Re: [PATCH 1/1] remoteproc: fix recovery procedure
> 
> 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
First rpmsg-ttyADSP announcement

> [   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
Second rpmsg-ttyADSP announcement

> [   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?

In your trace, I can see that your rpmsg device are announced twice and error is on the second announcement which is normal as endpoint ID is already used.
virtio_rpmsg_bus virtio2: rpmsg_create_channel failed --> means you can't get the requested idr.

In code you pointing in [1] I can see that you are using optimized version of rpmsg, having zero copy features and maybe others coming from rpmsg-lite.
On my side I'm testing with official release from OpenAMP and I have no modification on Linux rpmsg (on the top of kernel 5.0-rc0).
Could you check content of the shared memory after recovery sequence? Maybe previous messages are still present leading to double announcement.
Could you please retry on a mainline kernel without rpmsg optimization ?

On my side I tried the rpmsg_tty driver you pointed in [1] (I just add some stubs for zero copy) and I succeed to recover on my platform with it, so no issue on rpmsg client implementation side.

Regards,
Loic

[1] https://github.com/thesofproject/linux/pull/177


> 
> Thanks
> Xiang
> 
> On Tue, Jan 15, 2019 at 4:23 AM Loic PALLARDY <loic.pallardy@xxxxxx>
> wrote:
> >
> > Hi Xiang,
> >
> > > -----Original Message-----
> > > From: xiang xiao <xiaoxiang781216@xxxxxxxxx>
> > > Sent: samedi 12 janvier 2019 19:29
> > > To: Loic PALLARDY <loic.pallardy@xxxxxx>
> > > Cc: bjorn.andersson@xxxxxxxxxx; ohad@xxxxxxxxxx; linux-
> > > remoteproc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Arnaud
> > > POULIQUEN <arnaud.pouliquen@xxxxxx>;
> benjamin.gaignard@xxxxxxxxxx; s-
> > > anna@xxxxxx
> > > 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@xxxxxx>
> 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@xxxxxxxxx>
> > > > Signed-off-by: Loic Pallardy <loic.pallardy@xxxxxx>
> > > > ---
> > > >  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
> > > >