Re: [PATCH v3 2/2] pci/aer: interrupt fixup in the quirk

From: Bjorn Helgaas <helgaas@kernel.org>
To: Po Liu <po.liu@nxp.com>
Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
	Roy Zang <roy.zang@nxp.com>, Arnd Bergmann <arnd@arndb.de>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Stuart Yoder <stuart.yoder@nxp.com>,
	Yang-Leo Li <leoyang.li@nxp.com>,
	Minghuan Lian <minghuan.lian@nxp.com>,
	Murali Karicheri <m-karicheri2@ti.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Shawn Guo <shawnguo@kernel.org>, Mingkai Hu <mingkai.hu@nxp.com>
Subject: Re: [PATCH v3 2/2] pci/aer: interrupt fixup in the quirk
Date: Fri, 29 Jul 2016 17:41:54 -0500	[thread overview]
Message-ID: <20160729224154.GC13632@localhost> (raw)
In-Reply-To: <1465892645-32381-2-git-send-email-po.liu@nxp.com>

On Tue, Jun 14, 2016 at 04:24:05PM +0800, Po Liu wrote:
> On some platforms, root port doesn't support MSI/MSI-X/INTx in RC mode.
> When chip support the aer interrupt with none MSI/MSI-X/INTx mode,
> maybe there is interrupt line for aer pme etc. Search the interrupt
> number in the fdt file. Then fixup the dev->irq with it.
> 
> Signed-off-by: Po Liu <po.liu@nxp.com>

I'm not sure where we're at with this.  Dongdong had some issue
(possibly with a version of the quirk on a different platform?), and I
think the suggestion of explicitly checking for a root port device was
a good one.

So please update and repost this for next cycle.

> ---
> changes for V3:
> 	- Move to quirk;
> 	- Only correct the irq in RC mode;
> 
>  drivers/pci/quirks.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index ee72ebe..8b39cce 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -25,6 +25,7 @@
>  #include <linux/sched.h>
>  #include <linux/ktime.h>
>  #include <linux/mm.h>
> +#include <linux/of_irq.h>
>  #include <asm/dma.h>	/* isa_dma_bridge_buggy */
>  #include "pci.h"
>  
> @@ -4419,3 +4420,31 @@ static void quirk_intel_qat_vf_cap(struct pci_dev *pdev)
>  	}
>  }
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x443, quirk_intel_qat_vf_cap);
> +
> +/* If root port doesn't support MSI/MSI-X/INTx in RC mode,
> + * but use standalone irq. Read the device tree for the aer
> + * interrupt number.
> + */
> +static void quirk_aer_interrupt(struct pci_dev *dev)
> +{
> +	int ret;
> +	u8 header_type;
> +	struct device_node *np = NULL;
> +
> +	/* Only for the RC mode device */
> +	pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
> +	if ((header_type & 0x7F) != PCI_HEADER_TYPE_BRIDGE)
> +		return;
> +
> +	if (dev->bus->dev.of_node)
> +		np = dev->bus->dev.of_node;
> +
> +	if (IS_ENABLED(CONFIG_OF_IRQ) && np) {
> +		ret = of_irq_get_byname(np, "aer");
> +		if (ret > 0) {
> +			dev->no_msi = 1;
> +			dev->irq = ret;
> +		}
> +	}
> +}
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_FREESCALE, PCI_ANY_ID, quirk_aer_interrupt);
> -- 
> 2.1.0.27.g96db324
> 
> 
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