Re: [PATCH 7/8] PCI: designware: make MSI isr shared irq aware

[Jingoo Han <jg1.han@samsung.com>]

On Saturday, March 29, 2014 1:53 AM, Lucas Stach wrote:
> 
> On i.MX6 the host controller MSI irq is shared
> with PCI legacy INTD. Make sure we don't bail too
> early from the irq handler.
> 
> The issue is fairly theoretical as it would require
> a system setup with a PCIe switch where one connected
> device is using legacy INTD and another one using
> MSI, but better fix it now.
> 
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

(+cc Mohit KUMAR DCG, Pratyush ANAND)

Acked-by: Jingoo Han <jg1.han@samsung.com>

Best regards,
Jingoo Han

> ---
>  drivers/pci/host/pci-exynos.c      | 4 +---
>  drivers/pci/host/pcie-designware.c | 6 +++++-
>  drivers/pci/host/pcie-designware.h | 2 +-
>  3 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c
> index 3de6bfbbe8e9..b616d34922d8 100644
> --- a/drivers/pci/host/pci-exynos.c
> +++ b/drivers/pci/host/pci-exynos.c
> @@ -415,9 +415,7 @@ static irqreturn_t exynos_pcie_msi_irq_handler(int irq, void *arg)
>  {
>  	struct pcie_port *pp = arg;
> 
> -	dw_handle_msi_irq(pp);
> -
> -	return IRQ_HANDLED;
> +	return dw_handle_msi_irq(pp);
>  }
> 
>  static void exynos_pcie_msi_init(struct pcie_port *pp)
> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
> index 98c118e04dba..cbce9b04b13d 100644
> --- a/drivers/pci/host/pcie-designware.c
> +++ b/drivers/pci/host/pcie-designware.c
> @@ -156,15 +156,17 @@ static struct irq_chip dw_msi_irq_chip = {
>  };
> 
>  /* MSI int handler */
> -void dw_handle_msi_irq(struct pcie_port *pp)
> +irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
>  {
>  	unsigned long val;
>  	int i, pos, irq;
> +	irqreturn_t ret = IRQ_NONE;
> 
>  	for (i = 0; i < MAX_MSI_CTRLS; i++) {
>  		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS + i * 12, 4,
>  				(u32 *)&val);
>  		if (val) {
> +			ret = IRQ_HANDLED;
>  			pos = 0;
>  			while ((pos = find_next_bit(&val, 32, pos)) != 32) {
>  				irq = irq_find_mapping(pp->irq_domain,
> @@ -177,6 +179,8 @@ void dw_handle_msi_irq(struct pcie_port *pp)
>  			}
>  		}
>  	}
> +
> +	return ret;
>  }
> 
>  void dw_pcie_msi_init(struct pcie_port *pp)
> diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-designware.h
> index 3063b3594d88..a169d22d517e 100644
> --- a/drivers/pci/host/pcie-designware.h
> +++ b/drivers/pci/host/pcie-designware.h
> @@ -68,7 +68,7 @@ struct pcie_host_ops {
> 
>  int dw_pcie_cfg_read(void __iomem *addr, int where, int size, u32 *val);
>  int dw_pcie_cfg_write(void __iomem *addr, int where, int size, u32 val);
> -void dw_handle_msi_irq(struct pcie_port *pp);
> +irqreturn_t dw_handle_msi_irq(struct pcie_port *pp);
>  void dw_pcie_msi_init(struct pcie_port *pp);
>  int dw_pcie_link_up(struct pcie_port *pp);
>  void dw_pcie_setup_rc(struct pcie_port *pp);
> --
> 1.9.0