commit: 2cfda637e29ce9e3df31b59f64516b2e571cc985
From: Yinghai Lu <yinghai@xxxxxxxxxx>
Date: Mon, 1 Apr 2013 11:48:59 -0600
Subject: EISA/PCI: Fix bus res reference
Matthew 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.
pci_eisa_init() was using bus->resource[] directly instead of
pci_bus_resource_n(). The bus->resource[] array is a PCI-internal
implementation detail, and 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 buses any more.
The 82375 is a subtractive-decode PCI device, so handle it the same
way we handle PCI-PCI bridges in subtractive-decode mode in
pci_read_bridge_bases().
[bhelgaas: changelog]
Reported-by: Matthew Whitehead <mwhitehe@xxxxxxxxxx>
Tested-by: Matthew Whitehead <mwhitehe@xxxxxxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v3.3+
---
drivers/eisa/pci_eisa.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/drivers/eisa/pci_eisa.c b/drivers/eisa/pci_eisa.c
index cdae207..ef5c3ec 100644
--- a/drivers/eisa/pci_eisa.c
+++ b/drivers/eisa/pci_eisa.c
@@ -22,7 +22,8 @@ static struct eisa_root_device pci_eisa_root;
static int __init pci_eisa_init(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
- int rc;
+ int rc, i;
+ struct resource *res, *bus_res = NULL;
if ((rc = pci_enable_device (pdev))) {
printk (KERN_ERR "pci_eisa : Could not enable device %s\n",
@@ -30,9 +31,30 @@ static int __init pci_eisa_init(struct pci_dev *pdev,
return rc;
}
+ /*
+ * The Intel 82375 PCI-EISA bridge is a subtractive-decode PCI
+ * device, so the resources available on EISA are the same as those
+ * available on the 82375 bus. This works the same as a PCI-PCI
+ * bridge in subtractive-decode mode (see pci_read_bridge_bases()).
+ * We assume other PCI-EISA bridges are similar.
+ *
+ * eisa_root_register() can only deal with a single io port resource,
+ * so we use the first valid io port resource.
+ */
+ pci_bus_for_each_resource(pdev->bus, res, i)
+ if (res && (res->flags & IORESOURCE_IO)) {
+ bus_res = res;
+ break;
+ }
+
+ if (!bus_res) {
+ dev_err(&pdev->dev, "No resources available\n");
+ return -1;
+ }
+
pci_eisa_root.dev = &pdev->dev;
- pci_eisa_root.res = pdev->bus->resource[0];
- pci_eisa_root.bus_base_addr = pdev->bus->resource[0]->start;
+ pci_eisa_root.res = bus_res;
+ pci_eisa_root.bus_base_addr = bus_res->start;
pci_eisa_root.slots = EISA_MAX_SLOTS;
pci_eisa_root.dma_mask = pdev->dma_mask;
dev_set_drvdata(pci_eisa_root.dev, &pci_eisa_root);
--
1.7.10.4
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