Re: [PATCH v2 1/2] bus: mhi: core: Allow shared IRQ for event rings

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Mon, Sep 21, 2020 at 09:36:58AM +0200, Loic Poulain wrote:
> There is no requirement for using a dedicated IRQ per event ring.
> Some systems does not support multiple MSI vectors (e.g. intel
> without CONFIG_IRQ_REMAP), In that case the MHI controller can
> configure all the event rings to use the same interrupt (as fallback).
> 
> Allow this by removing the nr_irqs = ev_ring test and add extra check
> in the irq_setup function.
> 
> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Thanks,
Mani

> ---
>  v2: keep nr_irqs check early in init sequence
> 
>  drivers/bus/mhi/core/init.c | 7 +++++++
>  drivers/bus/mhi/core/pm.c   | 2 +-
>  2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 19ade8a..31961af 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -125,6 +125,13 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
>  		if (mhi_event->offload_ev)
>  			continue;
>  
> +		if (mhi_event->irq >= mhi_cntrl->nr_irqs) {
> +			dev_err(dev, "irq %d not available for event ring\n",
> +				mhi_event->irq);
> +			ret = -EINVAL;
> +			goto error_request;
> +		}
> +
>  		ret = request_irq(mhi_cntrl->irq[mhi_event->irq],
>  				  mhi_irq_handler,
>  				  IRQF_SHARED | IRQF_NO_SUSPEND,
> diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
> index ce4d969..3de7b16 100644
> --- a/drivers/bus/mhi/core/pm.c
> +++ b/drivers/bus/mhi/core/pm.c
> @@ -918,7 +918,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
>  
>  	dev_info(dev, "Requested to power ON\n");
>  
> -	if (mhi_cntrl->nr_irqs < mhi_cntrl->total_ev_rings)
> +	if (mhi_cntrl->nr_irqs < 1)
>  		return -EINVAL;
>  
>  	/* Supply default wake routines if not provided by controller driver */
> -- 
> 2.7.4
>