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[PATCH] yenta: fix hidden PCI bus numbers

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Fixup the subordinate number parent bridge of yenta Cardbus Bridges
before the PCI bus scan starts to make the cardbus cards which are
otherwise hidden for PCI scans work.

Signed-off-by: Bernhard Kaindl <bk@suse.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This commit is contained in:
Bernhard Kaindl 2006-05-30 18:00:34 +02:00 committed by Dominik Brodowski
parent d250a48104
commit b435261b1e
1 changed files with 73 additions and 0 deletions
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73
drivers/pcmcia/yenta_socket.c
View file

@ -1005,6 +1005,77 @@ static void yenta_config_init(struct yenta_socket *socket)
config_writew(socket, CB_BRIDGE_CONTROL, bridge);
}
/**
* yenta_fixup_parent_subordinate - Fix subordinate bus# of the parent bridge
* @cardbus_bridge: The PCI bus which the CardBus bridge bridges to
*
* Checks if devices on the bus which the CardBus bridge bridges to would be
* invisible during PCI scans because of a misconfigured subordinate number
* of the parent brige - some BIOSes seem to be too lazy to set it right.
* Does the fixup carefully by checking how far it can go without conflicts.
* See http://bugzilla.kernel.org/show_bug.cgi?id=2944 for more information.
*/
static void yenta_fixup_parent_bridge(struct pci_bus *cardbus_bridge)
{
struct list_head *tmp;
unsigned char upper_limit;
/*
* We only check and fix the parent bridge: All systems which need
* this fixup that have been reviewed are laptops and the only bridge
* which needed fixing was the parent bridge of the CardBus bridge:
*/
struct pci_bus *bridge_to_fix = cardbus_bridge->parent;
/* Check bus numbers are already set up correctly: */
if (bridge_to_fix->subordinate >= cardbus_bridge->subordinate)
return; /* The subordinate number is ok, nothing to do */
if (!bridge_to_fix->parent)
return; /* Root bridges are ok */
/* stay within the limits of the bus range of the parent: */
upper_limit = bridge_to_fix->parent->subordinate;
/* check the bus ranges of all silbling bridges to prevent overlap */
list_for_each(tmp, &bridge_to_fix->parent->children) {
struct pci_bus * silbling = pci_bus_b(tmp);
/*
* If the silbling has a higher secondary bus number
* and it's secondary is equal or smaller than our
* current upper limit, set the new upper limit to
* the bus number below the silbling's range:
*/
if (silbling->secondary > bridge_to_fix->subordinate
&& silbling->secondary <= upper_limit)
upper_limit = silbling->secondary - 1;
}
/* Show that the wanted subordinate number is not possible: */
if (cardbus_bridge->subordinate > upper_limit)
printk(KERN_WARNING "Yenta: Upper limit for fixing this "
"bridge's parent bridge: #%02x\n", upper_limit);
/* If we have room to increase the bridge's subordinate number, */
if (bridge_to_fix->subordinate < upper_limit) {
/* use the highest number of the hidden bus, within limits */
unsigned char subordinate_to_assign =
min(cardbus_bridge->subordinate, upper_limit);
printk(KERN_INFO "Yenta: Raising subordinate bus# of parent "
"bus (#%02x) from #%02x to #%02x\n",
bridge_to_fix->number,
bridge_to_fix->subordinate, subordinate_to_assign);
/* Save the new subordinate in the bus struct of the bridge */
bridge_to_fix->subordinate = subordinate_to_assign;
/* and update the PCI config space with the new subordinate */
pci_write_config_byte(bridge_to_fix->self,
PCI_SUBORDINATE_BUS, bridge_to_fix->subordinate);
}
}
/*
* Initialize a cardbus controller. Make sure we have a usable
* interrupt, and that we can map the cardbus area. Fill in the
@ -1120,6 +1191,8 @@ static int __devinit yenta_probe (struct pci_dev *dev, const struct pci_device_i
yenta_get_socket_capabilities(socket, isa_interrupts);
printk(KERN_INFO "Socket status: %08x\n", cb_readl(socket, CB_SOCKET_STATE));
yenta_fixup_parent_bridge(dev->subordinate);
/* Register it with the pcmcia layer.. */
ret = pcmcia_register_socket(&socket->socket);
if (ret == 0) {