Re: [PATCH 1/2] soc: ti: Use remoteproc auto_boot feature

[Sarangdhar Joshi]

On 12/23/2016 03:57 PM, Suman Anna wrote:
> On 12/23/2016 11:05 AM, Suman Anna wrote:
> > Hi Sarang,
> >
> > > > On 12/15/2016 06:03 PM, Sarangdhar Joshi wrote:
> > > > > The function wkup_m3_rproc_boot_thread waits for asynchronous
> > > > > firmware loading to complete successfully before calling
> > > > > rproc_boot(). The same can be achieved by just setting
> > > > > rproc->auto_boot flag. Change this. As a result this change
> > > > > removes wkup_m3_rproc_boot_thread and moves m3_ipc->sync_complete
> > > > > initialization to the wkup_m3_ipc_probe().
> > > > >
> > > > > Other than the current usage, the firmware_loading_complete is
> > > > > only used in rproc_del() where it's no longer needed.  This
> > > > > change is in preparation for removing firmware_loading_complete
> > > > > completely.
> > > >
> > > > Based on the comments so far, I am assuming that you are dropping this
> > > > series.
> > >
> > > No, may not be dropping this. Will try to handle it differently in
> > > rproc_del() (probably by making use of some state flag).
> > > > In any case, this series did break our PM stack. We definitely don't
> > > > want to auto-boot the wkup_m3_rproc device, that responsibility will
> > > > need to stay with the wkup_m3_ipc driver.
> > >
> > > Which scenario did it break? Booting up rproc device before
> > > wkup_m3_ipc_probe() causes issues?
> >
> > Yes, our state machine requires the wkup_m3_ipc driver to control the
> > boot of the wkup_m3 remoteproc. The wkup_m3 is not a typical remoteproc,
> > it is our PM master and is responsible for putting the host processor
> > into suspend and waking it up in system suspend/cpuidle paths.
> > The remoteproc infrastructure is only used for load/boot, but the Linux
> > PM state machine and communication is all controlled by the wkup_m3_ipc
> > driver.

Thanks for explaining. I was missing the fact that the resource table 
parsing during asynchronous call and the one in rproc_boot() are 
different.

> > > Nevertheless, I think Bjorn's suggestion of just dropping the call to
> > > wait_for_completion() and keeping kthread looks good, also because of
> > > the fact that rproc_boot() anyways calls request_firmware() and no
> > > longer needed to wait on asynchronous loading of firmware.
> >
> > Yeah, I will have to test this, but looking at current code, this should
> > mostly be ok because of the remoteproc core changes w.r.t resource table
> > parsing.
>
> Tested with just the wait_for_completion() removed and it works fine. I
> can send a patch for the same if you prefer me to send it.

Thanks for testing it. I have sent the patch.

Regards,
Sarang

> regards
> Suman
>
> > regards
> > Suman
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