PCI: Disable cardbus bridge MEM1 prefetchable bit
Some BIOSes enable prefetch on both MEM0 and MEM1. But the cardbus code
assumes MEM1 is non-pref...
Discussion could be found at:
https://lkml.org/lkml/2012/1/12/1
https://bugzilla.kernel.org/show_bug.cgi?id=41622#c23
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 090217a..d5897c3 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -914,6 +914,14 @@
if (realloc_head)
add_to_list(realloc_head, bridge, b_res+1, pci_cardbus_io_size, 0 /* dont care */);
+ /* MEM1 must not be pref mmio */
+ pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+ if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM1) {
+ ctrl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
+ pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
+ pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+ }
+
/*
* Check whether prefetchable memory is supported
* by this bridge.