Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
From: Bjorn Helgaas <bhelgaas@google.com>
Date: 2015-08-14 16:40:59
Also in:
linux-arm-kernel, linux-devicetree, linux-pci, lkml
On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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..545ff4e 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(of_chosen);
Do we need support for pci-probe-only in pci-host-generic at all? You're removing the use in amd-overdrive.dts, and there are no other DTs in the kernel tree that mention it. If we can live without it, that would be nice. It seems like a relic from days when we couldn't reliably assign resources. (I'm not saying we can do that reliably even today, but I'd rather make it reliable than turn it off.)
of_id = of_match_node(gen_pci_of_match, np); pci->cfg.ops = of_id->data; -- 2.1.4