PCI: Don't print anything while decoding is disabled

If we try to print to the console device while its decoding is disabled,
the system will hang.

Reported-and-tested-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Olof Johansson <olof@lixom.net>

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 6c143b4497ca4381677dcc34459ecf269e5cdc88..9f8a6b79a8ecf22d604056a902e7ca7adee8520a 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -144,15 +144,13 @@ static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar)
        case PCI_BASE_ADDRESS_MEM_TYPE_32:
                break;
        case PCI_BASE_ADDRESS_MEM_TYPE_1M:
-               dev_info(&dev->dev, "1M mem BAR treated as 32-bit BAR\n");
+               /* 1M mem BAR treated as 32-bit BAR */
                break;
        case PCI_BASE_ADDRESS_MEM_TYPE_64:
                flags |= IORESOURCE_MEM_64;
                break;
        default:
-               dev_warn(&dev->dev,
-                        "mem unknown type %x treated as 32-bit BAR\n",
-                        mem_type);
+               /* mem unknown type treated as 32-bit BAR */
                break;
        }
        return flags;
@@ -173,9 +171,11 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
        u32 l, sz, mask;
        u16 orig_cmd;
        struct pci_bus_region region;
+       bool bar_too_big = false, bar_disabled = false;
 
        mask = type ? PCI_ROM_ADDRESS_MASK : ~0;
 
+       /* No printks while decoding is disabled! */
        if (!dev->mmio_always_on) {
                pci_read_config_word(dev, PCI_COMMAND, &orig_cmd);
                pci_write_config_word(dev, PCI_COMMAND,
@@ -240,8 +240,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
                        goto fail;
 
                if ((sizeof(resource_size_t) < 8) && (sz64 > 0x100000000ULL)) {
-                       dev_err(&dev->dev, "reg %x: can't handle 64-bit BAR\n",
-                               pos);
+                       bar_too_big = true;
                        goto fail;
                }
 
@@ -252,12 +251,11 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
                        region.start = 0;
                        region.end = sz64;
                        pcibios_bus_to_resource(dev, res, &region);
+                       bar_disabled = true;
                } else {
                        region.start = l64;
                        region.end = l64 + sz64;
                        pcibios_bus_to_resource(dev, res, &region);
-                       dev_printk(KERN_DEBUG, &dev->dev, "reg %x: %pR\n",
-                                  pos, res);
                }
        } else {
                sz = pci_size(l, sz, mask);
@@ -268,18 +266,23 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
                region.start = l;
                region.end = l + sz;
                pcibios_bus_to_resource(dev, res, &region);
-
-               dev_printk(KERN_DEBUG, &dev->dev, "reg %x: %pR\n", pos, res);
        }
 
- out:
+       goto out;
+
+
+fail:
+       res->flags = 0;
+out:
        if (!dev->mmio_always_on)
                pci_write_config_word(dev, PCI_COMMAND, orig_cmd);
 
+       if (bar_too_big)
+               dev_err(&dev->dev, "reg %x: can't handle 64-bit BAR\n", pos);
+       if (res->flags && !bar_disabled)
+               dev_printk(KERN_DEBUG, &dev->dev, "reg %x: %pR\n", pos, res);
+
        return (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
- fail:
-       res->flags = 0;
-       goto out;
 }
 
 static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)