[Karmic] SRU: PCI/cardbus: Add a fixup hook and fix powerpc

Stefan Bader stefan.bader at canonical.com
Tue Jan 19 11:48:21 UTC 2010

SRU Justication:

Impact: On powerpc, the cardbus code needs to run through fixup code,
otherwise the kernel will crash with inserted cards.

Fix: The patch, backported from upstream, will create a fixup function
which is doing nothing on all architectures but powerpc. And for powerpc
it will call the required fixup code.
For Lucid this has been forwarded to stable at kernel.org, but the 2.6.31.y
support ended now.

Testcase: see bug report.

>From 8a76c709711ef4d555baa1ba540f45a6c6d8b440 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Date: Wed, 9 Dec 2009 17:52:13 +1100
Subject: [PATCH] PCI/cardbus: Add a fixup hook and fix powerpc

BugLink: http://bugs.launchpad.net/bugs/455723

commit 2d1c861871d767153538a77c498752b36d4bb4b8 upstream

The cardbus code creates PCI devices without ever going through the
necessary fixup bits and pieces that normal PCI devices go through.

There's in fact a commented out call to pcibios_fixup_bus() in there,
it's commented because ... it doesn't work.

I could make pcibios_fixup_bus() do the right thing on powerpc easily
but I felt it cleaner instead to provide a specific hook pci_fixup_cardbus
for which a weak empty implementation is provided by the PCI core.

This fixes cardbus on powerbooks and probably all other PowerPC
platforms which was broken completely for ever on some platforms and
since 2.6.31 on others such as PowerBooks when we made the DMA ops
mandatory (since those are setup by the fixups).

Acked-by: Dominik Brodowski <linux at dominikbrodowski.net>
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
Signed-off-by: Stefan Bader <stefan.bader at canonical.com>
Acked-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Acked-by: Jesse Barnes <jbarnes at virtuousgeek.org>
 arch/powerpc/kernel/pci-common.c |   13 +++++++++++++
 drivers/pci/pci.c                |    5 +++++
 drivers/pcmcia/cardbus.c         |    2 +-
 include/linux/pci.h              |    3 +++
 4 files changed, 22 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index e8dfdbd..cadbed6 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1107,6 +1107,12 @@ void __devinit pcibios_setup_bus_devices(struct pci_bus *bus)
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		struct dev_archdata *sd = &dev->dev.archdata;
+		/* Cardbus can call us to add new devices to a bus, so ignore
+		 * those who are already fully discovered
+		 */
+		if (dev->is_added)
+			continue;
 		/* Setup OF node pointer in archdata */
 		sd->of_node = pci_device_to_OF_node(dev);
@@ -1147,6 +1153,13 @@ void __devinit pcibios_fixup_bus(struct pci_bus *bus)
+void __devinit pci_fixup_cardbus(struct pci_bus *bus)
+	/* Now fixup devices on that bus */
+	pcibios_setup_bus_devices(bus);
 static int skip_isa_ioresource_align(struct pci_dev *dev)
 	if ((ppc_pci_flags & PPC_PCI_CAN_SKIP_ISA_ALIGN) &&
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 4e4c295..6477722 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2723,6 +2723,11 @@ int __attribute__ ((weak)) pci_ext_cfg_avail(struct pci_dev *dev)
 	return 1;
+void __weak pci_fixup_cardbus(struct pci_bus *bus)
 static int __init pci_setup(char *str)
 	while (str) {
diff --git a/drivers/pcmcia/cardbus.c b/drivers/pcmcia/cardbus.c
index db77e1f..5c26793 100644
--- a/drivers/pcmcia/cardbus.c
+++ b/drivers/pcmcia/cardbus.c
@@ -214,7 +214,7 @@ int __ref cb_alloc(struct pcmcia_socket * s)
 	unsigned int max, pass;
 	s->functions = pci_scan_slot(bus, PCI_DEVFN(0, 0));
-//	pcibios_fixup_bus(bus);
+	pci_fixup_cardbus(bus);
 	max = bus->secondary;
 	for (pass = 0; pass < 2; pass++)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index f5c7cd3..2547515 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -564,6 +564,9 @@ void pcibios_align_resource(void *, struct resource *, resource_size_t,
 void pcibios_update_irq(struct pci_dev *, int irq);
+/* Weak but can be overriden by arch */
+void pci_fixup_cardbus(struct pci_bus *);
 /* Generic PCI functions used internally */
 extern struct pci_bus *pci_find_bus(int domain, int busnr);

More information about the kernel-team mailing list