From 2cfda637e29ce9e3df31b59f64516b2e571cc985 Mon Sep 17 00:00:00 2001 From: Yinghai Lu 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 Tested-by: Matthew Whitehead Signed-off-by: Yinghai Lu Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org # v3.3+ --- drivers/eisa/pci_eisa.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) (limited to 'drivers/eisa') diff --git a/drivers/eisa/pci_eisa.c b/drivers/eisa/pci_eisa.c index cdae207028a7..ef5c3ec87432 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); -- cgit v1.2.1