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

[Stephan Gerhold <stephan.gerhold@linaro.org>]

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. :-)

In any case:

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

Thanks,
Stephan