Re: [PATCH v12 08/13] arm_mpam: propagate MSC access errors for interrupt control

[Ben Horgan]

Hi Andre,

On 01/10/2026 16:34, Andre Przywara wrote:
> Allow the functions dealing with interrupt registration and enablement
> to check for and return errors, and propagate MSC read and write errors
> from the lower level up.
> This does not cover the IRQ handler yet, as this needs some more
> attention.
> 
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> Reviewed-by: Srivathsa L Rao <srivathsa.rao@xxxxxxxxxxxxxxxx>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxxxxxxxx>

Reviewed-by: Ben Horgan <ben.horgan@xxxxxxx>

Thanks,

Ben

> ---
>  drivers/resctrl/mpam_devices.c | 23 +++++++++++------------
>  1 file changed, 11 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
> index b876f4d2e9a77..60f6a39176ea1 100644
> --- a/drivers/resctrl/mpam_devices.c
> +++ b/drivers/resctrl/mpam_devices.c
> @@ -1118,7 +1118,9 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc)
>  	}
>  
>  	/* Clear any stale errors */
> -	mpam_msc_clear_esr(msc);
> +	ret = mpam_msc_clear_esr(msc);
> +	if (ret)
> +		return ret;
>  
>  	spin_lock(&partid_max_lock);
>  	mpam_partid_max = min(mpam_partid_max, msc->partid_max);
> @@ -2681,9 +2683,7 @@ static int mpam_enable_msc_ecr(void *_msc)
>  {
>  	struct mpam_msc *msc = _msc;
>  
> -	__mpam_write_reg(msc, MPAMF_ECR, MPAMF_ECR_INTEN);
> -
> -	return 0;
> +	return __mpam_write_reg(msc, MPAMF_ECR, MPAMF_ECR_INTEN);
>  }
>  
>  /* This can run in mpam_disable(), and the interrupt handler on the same CPU */
> @@ -2691,9 +2691,7 @@ static int mpam_disable_msc_ecr(void *_msc)
>  {
>  	struct mpam_msc *msc = _msc;
>  
> -	__mpam_write_reg(msc, MPAMF_ECR, 0);
> -
> -	return 0;
> +	return __mpam_write_reg(msc, MPAMF_ECR, 0);
>  }
>  
>  static irqreturn_t __mpam_irq_handler(int irq, struct mpam_msc *msc)
> @@ -2790,11 +2788,12 @@ static int mpam_register_irqs(void)
>  				return err;
>  		}
>  
> -		mutex_lock(&msc->error_irq_lock);
> +		guard(mutex)(&msc->error_irq_lock);
>  		msc->error_irq_req = true;
> -		mpam_touch_msc(msc, mpam_enable_msc_ecr, msc);
> +		err = mpam_touch_msc(msc, mpam_enable_msc_ecr, msc);
> +		if (err)
> +			return err;
>  		msc->error_irq_hw_enabled = true;
> -		mutex_unlock(&msc->error_irq_lock);
>  	}
>  
>  	return 0;
> @@ -2815,8 +2814,8 @@ static void mpam_unregister_irqs(void)
>  
>  		mutex_lock(&msc->error_irq_lock);
>  		if (msc->error_irq_hw_enabled) {
> -			mpam_touch_msc(msc, mpam_disable_msc_ecr, msc);
> -			msc->error_irq_hw_enabled = false;
> +			if (!mpam_touch_msc(msc, mpam_disable_msc_ecr, msc))
> +				msc->error_irq_hw_enabled = false;
>  		}
>  
>  		if (msc->error_irq_req) {