On 7/2/25 2:18 AM, Arnaud POULIQUEN wrote:
On 7/1/25 23:19, Tanmay Shah wrote:
On 7/1/25 1:06 PM, Tanmay Shah wrote:
On 7/1/25 12:56 PM, Tanmay Shah wrote:
On 7/1/25 12:18 PM, Arnaud POULIQUEN wrote:
On 7/1/25 17:16, Tanmay Shah wrote:
On 7/1/25 3:07 AM, Arnaud POULIQUEN wrote: > Hi Tanmay, > > On 6/27/25 23:29, Tanmay Shah wrote: >> Hello all, >> >> I am implementing remoteproc recovery on attach-detach use case. >> I have implemented the feature in the platform driver, and it works for boot >> recovery. > > Few questions to better understand your use case. > > 1) The linux remoteproc firmware attach to a a remote processor, and you > generate a crash of the remote processor, right? >
Yes correct.
> 1) How does the remoteprocessor reboot? On a remoteproc request or it is an > autoreboot independent from the Linux core? >
It is auto-reboot independent from the linux core.
> 2) In case of auto reboot, when does the remoteprocessor send an even to the > Linux remoteproc driver ? beforeor after the reset? >
Right now, when Remote reboots, it sends crash event to remoteproc driver after reboot.
> 3) Do you expect to get core dump on crash? >
No coredump expected as of now, but only recovery. Eventually will implement coredump functionality as well.
>> >> However, I am stuck at the testing phase. >> >> When should firmware report the crash ? After reboot ? or during some >> kind of >> crash handler ? >> >> So far, I am reporting crash after rebooting remote processor, but it >> doesn't >> seem to work i.e. I don't see rpmsg devices created after recovery.> >> What should be the correct process to test this feature ? How other >> platforms >> are testing this? > > I have never tested it on ST board. As a first analysis, in case of > autoreboot > of the remote processor, it look like you should detach and reattach to > recover.
That is what's done from the remoteproc framework.
> - On detach the rpmsg devices should be unbind > - On attach the remote processor should request RPmsg channels using the NS > announcement mechanism >
Main issue is, Remote firmware needs to wait till all above happens. Then only initialize virtio devices. Currently we don't have any way to notify recovery progress from linux to remote fw in the remoteproc framework. So I might have to introduce some platform specific mechanism in remote firmware to wait for recovery to complete successfully.
I guess the rproc->clean_table contains a copy of the resource table that is reapplied on attach, and the virtio devices should be re-probed, right?
During the virtio device probe, the vdev status in the resource table is updated to 7 when virtio is ready to communicate. Virtio should then call rproc_virtio_notify() to inform the remote processor of the status update. At this stage, your remoteproc driver should be able to send a mailbox message to inform the remote side about the recovery completion.
I think I spot the problem now.
Linux side: file: remoteproc_core.c rproc_attach_recovery __rproc_detach cleans up the resource table and re-loads it __rproc_attach stops and re-starts subdevices
Remote side: Remote re-boots after crash Detects crash happened previously notify crash to Linux (Linux is executing above flow meanwhile) starts creating virtio devices **rproc_virtio_create_vdev - parse vring & create vdev device** **rproc_virtio_wait_remote_ready - wait for remote ready** [1]
I think Remote should wait on DRIVER_OK bit, before creating virtio devices. The temporary solution I implemented was to make sure vrings addresses are not 0xffffffff like following:
while(rsc->rpmsg_vring0.da == FW_RSC_U32_ADDR_ANY || rsc->rpmsg_vring1.da == FW_RSC_U32_ADDR_ANY) { usleep(100); metal_cache_invalidate(rsc, rproc->rsc_len); }
Above works, but I think better solution is to change sequence where remote waits before creating virtio devices.
I am sorry, I should have said, remote should wait before parsing and assigning vrings to virtio device.
[1] https://github.com/OpenAMP/open-amp/ blob/391671ba24840833d882c1a75c5d7307703b1cf1/lib/remoteproc/ remoteproc.c#L994
Actually upon further checking, I think above code is okay. I see that wait_remote_ready is called before vrings are setup on remote fw side.
However, during recovery time on remote side, somehow I still have to implement platform specific wait for vrings to setup correctly.
From linux side, DRIVER_OK bit is set before vrings are setup correctly. Because of that, when remote firmware sets up wrong vring addresses and then rpmsg channels are not created.
I am investigating on this further.
Do you reset the vdev status as requested by the virtio spec? https://docs.oasis-open.org/virtio/virtio/v1.3/csd01/virtio-v1.3-csd01.html#...
Regards, Arnaud
Yes I do. I am actually restoring deafult resource table on firmware side, which will set rpmsg_vdev status to 0.
However, when printing vrings right before wait_remote_ready, I see vrings are not set correctly from linux side:
`vring0 = 0xFFFFFFFF, vring1 = 0xFFFFFFFF`
However, the rproc state was still moved to attach when checked from remoteproc sysfs.
`cat /sys/class/remoteproc/remoteproc0/state` attached
Somehow the sync between remote fw and linux isn't right.
Thanks, Tanmay
Regards Arnaud
> Regards, > Arnaud > >> >> >> Thanks, >> Tanmay