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Date:   Tue, 6 Apr 2021 17:28:37 -0600
From:   Mathieu Poirier <mathieu.poirier@linaro.org>
To:     Suman Anna <s-anna@ti.com>
Cc:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>,
        Jan Kiszka <jan.kiszka@siemens.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Lokesh Vutla <lokeshvutla@ti.com>,
        linux-remoteproc@vger.kernel.org, linux-omap@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] remoteproc: pru: Fixup interrupt-parent logic for fw
 events
Message-ID: <20210406232837.GA330882@xps15>
References: <20210323223839.17464-1-s-anna@ti.com>
 <20210323223839.17464-2-s-anna@ti.com>
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On Tue, Mar 23, 2021 at 05:38:37PM -0500, Suman Anna wrote:
> The PRU firmware interrupt mapping logic in pru_handle_intrmap() uses
> of_irq_find_parent() with PRU device node to get a handle to the PRUSS
> Interrupt Controller at present. This logic however requires that the
> PRU nodes always define a interrupt-parent property. This property is
> neither a required/defined property as per the PRU remoteproc binding,
> nor is relevant from a DT node point of view without any associated
> interrupts. The curret logic finds a wrong interrupt controller and
> fails to perform proper mapping without any interrupt-parent property
> in the PRU nodes.
> 
> Fix this logic to always find and use the sibling interrupt controller.
> Also, while at this, fix the acquired interrupt controller device node
> reference properly.
> 
> Fixes: c75c9fdac66e ("remoteproc: pru: Add support for PRU specific interrupt configuration")
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/remoteproc/pru_rproc.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
> index 16979c1cd2f4..a9d07c0751be 100644
> --- a/drivers/remoteproc/pru_rproc.c
> +++ b/drivers/remoteproc/pru_rproc.c
> @@ -284,7 +284,7 @@ static int pru_handle_intrmap(struct rproc *rproc)
>  	struct pru_rproc *pru = rproc->priv;
>  	struct pru_irq_rsc *rsc = pru->pru_interrupt_map;
>  	struct irq_fwspec fwspec;
> -	struct device_node *irq_parent;
> +	struct device_node *parent, *irq_parent;
>  	int i, ret = 0;
>  
>  	/* not having pru_interrupt_map is not an error */
> @@ -312,9 +312,16 @@ static int pru_handle_intrmap(struct rproc *rproc)
>  
>  	/*
>  	 * parse and fill in system event to interrupt channel and
> -	 * channel-to-host mapping
> +	 * channel-to-host mapping. The interrupt controller to be used
> +	 * for these mappings for a given PRU remoteproc is always its
> +	 * corresponding sibling PRUSS INTC node.
>  	 */
> -	irq_parent = of_irq_find_parent(pru->dev->of_node);

If I understand correctly when an interrupt controller node wasn't speficied in
the parent this was unwinding until it found one...

> +	parent = of_get_parent(dev_of_node(pru->dev));
> +	if (!parent)
> +		return -ENODEV;
> +
> +	irq_parent = of_get_child_by_name(parent, "interrupt-controller");
> +	of_node_put(parent);
>  	if (!irq_parent) {
>  		kfree(pru->mapped_irq);
>  		return -ENODEV;
> @@ -337,11 +344,13 @@ static int pru_handle_intrmap(struct rproc *rproc)
>  			goto map_fail;
>  		}
>  	}
> +	of_node_put(irq_parent);
>  
>  	return ret;
>  
>  map_fail:
>  	pru_dispose_irq_mapping(pru);
> +	of_node_put(irq_parent);

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

>  
>  	return ret;
>  }
> -- 
> 2.30.1
>