Re: [PATCH 1/2] remoteproc: qcom: pas: Decide early_boot attach at probe time

[Shawn Guo <shengchao.guo@oss.qualcomm.com>]

On Fri, Oct 09, 2026 at 04:20:58PM +0200, Stephan Gerhold wrote:
> On Tue, Oct 06, 2026 at 11:35:49AM +0800, Shawn Guo wrote:
> > For early_boot subsystems, probe unconditionally marks the rproc
> > RPROC_DETACHED and qcom_pas_attach() discovers from SMP2P whether the
> > bootloader actually started the remote. If it did not, attach sets the
> > state back to RPROC_OFFLINE and fails, expecting the core to boot the
> > firmware instead. The core does not do that: rproc_boot() treats the
> > attach failure as fatal and the remote is never started.
> > 
> > This is hit on Nord with firmware where XBL no longer brings ADSP out
> > of reset. The remote never publishes its inbound SMP2P entries, so the
> > very first state read fails (debug print below) and the ADSP stays down:
> > 
> >   qcom_q6v5_pas 4c00000.remoteproc: Failed to get fatal_irq state: -19
> >   remoteproc remoteproc0: can't attach to rproc adsp: -19
> > 
> > The ready, stop-ack and sysmon shutdown-ack signals cannot change while
> > Linux has not yet interacted with the remote, so there is no reason to
> > defer the decision to attach time. Check them in probe and only mark
> > the rproc RPROC_DETACHED when the remote is up and has not been asked
> > to stop; otherwise leave it RPROC_OFFLINE so the regular firmware boot
> > path is taken. The ready state is read first so that a missing SMP2P
> > entry -ENODEV is treated as "not running" before sysmon is queried.
> > 
> > qcom_pas_attach() keeps only the fatal check, since that is the one
> > signal that has to be acted upon once the rproc is attached.
> > 
> > Assisted-by: LLM
> > Signed-off-by: Shawn Guo <shengchao.guo@oss.qualcomm.com>
> > ---
> >  drivers/remoteproc/qcom_q6v5_pas.c | 64 +++++++++++++++---------------
> >  1 file changed, 33 insertions(+), 31 deletions(-)
> > 
> > diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
> > index 2e1e39826ffa..8f3d45c604c9 100644
> > --- a/drivers/remoteproc/qcom_q6v5_pas.c
> > +++ b/drivers/remoteproc/qcom_q6v5_pas.c
> > @@ -550,9 +550,7 @@ static unsigned long qcom_pas_panic(struct rproc *rproc)
> >  static int qcom_pas_attach(struct rproc *rproc)
> >  {
> >  	struct qcom_pas *pas = rproc->priv;
> > -	bool ready_state;
> >  	bool crash_state;
> > -	bool stop_state;
> >  	int ret;
> >  
> >  	pas->q6v5.handover_issued = true;
> > @@ -570,42 +568,46 @@ static int qcom_pas_attach(struct rproc *rproc)
> >  		goto disable_running;
> >  	}
> >  
> > -	ret = irq_get_irqchip_state(pas->q6v5.stop_irq,
> > -				    IRQCHIP_STATE_LINE_LEVEL, &stop_state);
> > -	if (ret)
> > -		goto disable_running;
> > -
> > -	if (stop_state || qcom_sysmon_shutdown_irq_state(pas->sysmon)) {
> > -		dev_info(pas->dev, "Subsystem found stop state set. Falling back to start.\n");
> > -		goto unroll_attach;
> > -	}
> > -
> > -	ret = irq_get_irqchip_state(pas->q6v5.ready_irq,
> > -				    IRQCHIP_STATE_LINE_LEVEL, &ready_state);
> > -	if (ret)
> > -		goto disable_running;
> > -
> > -	if (unlikely(!ready_state)) {
> > -		/*
> > -		 * The bootloader may not support early boot, mark the state as
> > -		 * RPROC_OFFLINE so that the PAS driver can load the firmware and
> > -		 * start the remoteproc.
> > -		 */
> > -		dev_err(pas->dev, "Failed to get subsystem ready interrupt\n");
> > -		goto unroll_attach;
> > -	}
> > -
> >  	return 0;
> >  
> > -unroll_attach:
> > -	pas->rproc->state = RPROC_OFFLINE;
> > -	ret = -EINVAL;
> >  disable_running:
> >  	pas->q6v5.running = false;
> >  
> >  	return ret;
> >  }
> >  
> > +/*
> > + * The bootloader may or may not have started the subsystem. Inspect the
> > + * SMP2P state, which is static until Linux interacts with the remote, to
> > + * decide whether to attach or to load and start the firmware.
> > + */
> > +static bool qcom_pas_is_running(struct qcom_pas *pas)
> > +{
> > +	bool ready_state;
> > +	bool stop_state;
> > +	int ret;
> > +
> > +	/*
> > +	 * Check ready first: if the remote never published its SMP2P
> > +	 * entries the state read fails with -ENODEV.
> > +	 */
> > +	ret = irq_get_irqchip_state(pas->q6v5.ready_irq,
> > +				    IRQCHIP_STATE_LINE_LEVEL, &ready_state);
> > +	if (ret || !ready_state) {
> > +		dev_info(pas->dev, "Subsystem not running. Falling back to start.\n");
> > +		return false;
> > +	}
> > +
> > +	ret = irq_get_irqchip_state(pas->q6v5.stop_irq,
> > +				    IRQCHIP_STATE_LINE_LEVEL, &stop_state);
> > +	if (ret || stop_state || qcom_sysmon_shutdown_irq_state(pas->sysmon)) {
> > +		dev_info(pas->dev, "Subsystem found stop state set. Falling back to start.\n");
> > +		return false;
> > +	}
> 
> Nitpick: Both of these messages are a bit imprecise. desc->early_boot
> does not necessarily imply desc->auto_boot, so they may just be marked
> as offline and not automatically started.
> 
> But you just moved this code and I don't think it's worth resending just
> to polish these messages a bit more. :-)

Since I need to send v2 to address your comments on patch 2/2, I will
change both messages to "…, not attaching".

> 
> In any case:
> 
> Reviewed-by: Stephan Gerhold <stephan.gerhold@linaro.org>

Thank you, Stephan!

Shawn