Re: [RFC PATCH v2] soc: qcom: rmtfs_mem: Control remoteproc from rmtfs_mem

[Sibi Sankar]

Hi Bjorn,
Thanks for the review!

On 2018-10-22 01:46, Bjorn Andersson wrote:
> On Sun 30 Sep 08:56 PDT 2018, Sibi Sankar wrote:
>
> > From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> >
> > rmtfs_mem provides access to physical storage and is crucial for the
> > operation of the Qualcomm modem subsystem.
> >
> > The rmtfs_mem implementation must be available before the modem
> > subsystem is booted and a solution where the modem remoteproc will
> > verify that the rmtfs_mem is available has been discussed in the past.
> > But this would not handle the case where the rmtfs_mem provider is
> > restarted, which would cause fatal loss of access to the storage 
> > device
> > for the modem.
> >
> > The suggestion is therefore to link the rmtfs_mem to its associated
> > remote processor instance and control it based on the availability of
> > the rmtfs_mem implementation.
> >
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > [sibis: Added qmi lookup for Remote file system service]
> > Signed-off-by: Sibi Sankar <sibis@xxxxxxxxxxxxxx>
>
> Thanks Sibi,
>
> This looks clean and straight forward, but I think the logic should be
> moved into the qcom_q6v5_mss driver itself - as we now only care about
> the QMI service being present, not the rmtfs_memory driver.

Will move it to qcom_q6v5_mss in the next re-spin.

The only drawback I found is that occasionally we receive the
the watchdog immediately after we kill the rmtfs application.
But eventually it gets handled as expected.

SDM845 Logs:
2360 root       0:00 rmtfs
/ # kill 2360

remoteproc: watchdog received: sys_m_smsm_mpss.c:285:APPS force stop
remoteproc0: crash detected in 4080000.remoteproc: type watchdog
qcom-q6v5-mss 4080000.remoteproc: timed out on wait
qcom-q6v5-mss 4080000.remoteproc: port failed halt
remoteproc remoteproc0: stopped remote processor 4080000.remoteproc


> There's nothing left of my original patch, so please credit yourself as
> author of v3.
>
> [..]
> > diff --git a/drivers/soc/qcom/rmtfs_mem.c 
> > b/drivers/soc/qcom/rmtfs_mem.c
> [..]
> > @@ -181,6 +217,22 @@ static int qcom_rmtfs_mem_probe(struct 
> > platform_device *pdev)
> >  	rmtfs_mem->client_id = client_id;
> >  	rmtfs_mem->size = rmem->size;
> >
> > +	ret = of_property_read_u32(node, "rproc", &rproc_phandle);
> > +	if (!ret) {
> > +		rmtfs_mem->rproc = rproc_get_by_phandle(rproc_phandle);
> > +		if (!rmtfs_mem->rproc)
> > +			return -EPROBE_DEFER;
> > +	}
> > +
> > +	ret = qmi_handle_init(&rmtfs_mem->rmtfs_hdl, 0,
> > +			      &rmtfs_lookup_ops, NULL);
> > +	if (ret < 0)
> > +		goto put_rproc;
> > +
> > +	ret = qmi_add_lookup(&rmtfs_mem->rmtfs_hdl, 14, 0, 0);
>
> The 14 here deserves a define and the whole thing would benefit from a
> comment describing the remoteproc's dependency on the RMTFS service
> being present.

Will add it in the respin

> > +	if (ret < 0)
> > +		goto err_release_qmi_handle;
> > +
> >  	device_initialize(&rmtfs_mem->dev);
> >  	rmtfs_mem->dev.parent = &pdev->dev;
> >  	rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups;
>
> Looking forward to v3!

Done :)

> Regards,
> Bjorn

-- Sibi Sankar --
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