On Fri, Mar 29, 2013 at 11:10 AM, Bjorn Helgaas <bhelg...@google.com> wrote:
> On Wed, Mar 27, 2013 at 10:28 PM, Yinghai Lu <ying...@kernel.org> wrote:
>> Matthem found that 3.8.3 is having problems with an old (ancient)
>> PCI-to-EISA bridge, the Intel 82375. It worked with the 3.2 kernel.
>> He identified the 82375, but doesn't assign the struct resource *res
>> pointer inside the struct eisa_root_device, and panics.
>>
>> After looking at pci_eisa_init(), found it referring bus resource
>> directly instead of pci_bus_resource_n().
>>
>> After commit 45ca9e97 (PCI: add helpers for building PCI bus resource lists)
>> and commit 0efd5aab (PCI: add struct pci_host_bridge_window with CPU/bus
>> address offset), bus->resource[] is not used for pci root bus any more.
>>
>> Fix it by using pci_bus_resource_n() and correct idx for root bus.
>>
>> Reported-by: Matthew Whitehead <mwhit...@redhat.com>
>> Tested-by: Matthew Whitehead <mwhit...@redhat.com>
>> Signed-off-by: Yinghai Lu <ying...@kernel.org>
>> Cc: sta...@kernel.org
>>
>> ---
>> drivers/eisa/pci_eisa.c | 10 +++++++---
>> 1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> Index: linux-2.6/drivers/eisa/pci_eisa.c
>> ===================================================================
>> --- linux-2.6.orig/drivers/eisa/pci_eisa.c
>> +++ linux-2.6/drivers/eisa/pci_eisa.c
>> @@ -22,7 +22,8 @@ static struct eisa_root_device pci_eisa_
>> static int __init pci_eisa_init(struct pci_dev *pdev,
>> const struct pci_device_id *ent)
>> {
>> - int rc;
>> + int rc, n = 0;
>> + struct resource *bus_res;
>>
>> if ((rc = pci_enable_device (pdev))) {
>> printk (KERN_ERR "pci_eisa : Could not enable device %s\n",
>> @@ -30,9 +31,12 @@ static int __init pci_eisa_init(struct p
>> return rc;
>> }
>>
>> + if (pci_is_root_bus(pdev->bus))
>> + n = PCI_BRIDGE_RESOURCE_NUM;
>> + bus_res = pci_bus_resource_n(pdev->bus, n);
>
> I haven't figured out why the pci_is_root_bus() test is here. Can you
> explain, maybe with a sample dmesg log and "lspci -vvx" output?
Just forwarded two boot.log.
for root bus, pci_bus_resource_n[0, PCI_BRIDGE_RESOURCE_NUM) all
equal to 0.
>
> Doesn't the 82375 subtractively decode this PCI memory space, the same
> way a subtractive-decode P2P bridge does? Can we make this code look
> like the "if (dev->transparent)" block in pci_read_bridge_bases(),
> just breaking after the first resource we find, since
> eisa_root_register() can only deal with a single resource on the EISA
> bus?
they are using extra resource in pci_eisa_root.eisa_root_res to prevent multiple
registering between pci_eisa and virtual platform.
and later eisa resource does get registered under system root ioport resource.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
