path: root/drivers/pci/setup-bus.c
diff options
authorAndrew Morton <akpm@osdl.org>2006-12-22 01:11:36 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-22 08:55:51 -0800
commitfe0e5c4d947d34f10002b4cf272f0ebf110305b7 (patch)
tree0f514dc726ab1fa80386dc2a3827661eb6e34b37 /drivers/pci/setup-bus.c
parent192636ad9097b13d58310a6358fd512d3084c09a (diff)
Linus sayeth: Google knows everything, and finds, on MS own site no less: "Windows 2000 default resources: One 4K memory window One 2 MB memory window Two 256-byte I/O windows" which is clearly utterly bogus and insufficient. But Microsoft apparently realized this, and: "Windows XP default resources: Because one memory window of 4K and one window of 2 MB are not sufficient for CardBus controllers in many configurations, Windows XP allocates larger memory windows to CardBus controllers where possible. However, resource windows are static (that is, the operating system does not dynamically allocate larger memory windows if new devices appear.) Under Windows XP, CardBus controllers will be assigned the following resources: One 4K memory window, as in Windows 2000 64 MB memory, if that amount of memory is available. If 64 MB is not available the controller will receive 32 MB; if 32 MB is not available, the controller will receive 16 MB; if 16 MB is not available, the bridge will receive 8 MB; and so on down to a minimum assignment of 1 MB in configurations where memory is too constrained for the operating system to provide a larger window. Two 256-byte I/O windows" So I think we have our answer. Windows uses one 4k window, and one 64MB window. And they are no more dynamic than we are (we _could_ try to do it dynamically, but let's face it, it's fairly painful to dynamically expand PCI bus resources - you may need to reprogram everything up to the root, so it would be absolutely crazy to do that unless you have some serious masochistic tendencies). So let's just increase our default value to 64M too. Cc: Markus Rechberger <mrechberger@gmail.com> Cc: Daniel Ritz <daniel.ritz@gmx.ch> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/pci/setup-bus.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 8f7bcf56f14..89f3036f0de 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -41,7 +41,7 @@
* have a P2P bridge below a cardbus bridge, we need 4K.
#define CARDBUS_IO_SIZE (256)
-#define CARDBUS_MEM_SIZE (32*1024*1024)
+#define CARDBUS_MEM_SIZE (64*1024*1024)
static void __devinit
pbus_assign_resources_sorted(struct pci_bus *bus)