Re: [PATCH v4 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property

From: Will Deacon
Date: Mon Sep 07 2015 - 05:15:49 EST


On Fri, Sep 04, 2015 at 05:50:09PM +0100, Marc Zyngier wrote:
> When pci-host-generic looks for the probe-only property, it seems
> to trust the DT to be correctly written, and assumes that there
> is a parameter to the property.
>
> Unfortunately, this is not always the case, and some firmware expose
> this property naked. The driver ends up making a decision based on
> whatever the property pointer points to, which is likely to be junk.
>
> Switch to the common of_pci.c implementation that doesn't suffer
> from this problem.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
> drivers/pci/host/pci-host-generic.c | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
> index 265dd25..224303d 100644
> --- a/drivers/pci/host/pci-host-generic.c
> +++ b/drivers/pci/host/pci-host-generic.c
> @@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
> int err;
> const char *type;
> const struct of_device_id *of_id;
> - const int *prop;
> struct device *dev = &pdev->dev;
> struct device_node *np = dev->of_node;
> struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
> @@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
> return -EINVAL;
> }
>
> - prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
> - if (prop) {
> - if (*prop)
> - pci_add_flags(PCI_PROBE_ONLY);
> - else
> - pci_clear_flags(PCI_PROBE_ONLY);
> - }
> + of_pci_check_probe_only();

Looks good to me:

Acked-by: Will Deacon <will.deacon@xxxxxxx>

Thanks, Marc.

Will
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