Commit 96941026 authored by mark gross's avatar mark gross Committed by Linus Torvalds

[PATCH] EDAC Coexistence with BIOS

Address the issue of EDAC/BIOS coexistence for the e752x chip-sets.

We have found a problem where the BIOS will start the system with the error
registers (dev0:fun1) hidden and assuming it has exclusive access to them.
The edac driver violates this assumption.

The workaround this patch offers is to honor the hidden-ness as an
indication that it is not safe to use those registers.
Signed-off-by: default avatarMark Gross <mark.gross@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6760da01
...@@ -25,6 +25,8 @@ ...@@ -25,6 +25,8 @@
#include <linux/slab.h> #include <linux/slab.h>
#include "edac_mc.h" #include "edac_mc.h"
static int force_function_unhide;
#define e752x_printk(level, fmt, arg...) \ #define e752x_printk(level, fmt, arg...) \
edac_printk(level, "e752x", fmt, ##arg) edac_printk(level, "e752x", fmt, ##arg)
...@@ -782,8 +784,16 @@ static int e752x_probe1(struct pci_dev *pdev, int dev_idx) ...@@ -782,8 +784,16 @@ static int e752x_probe1(struct pci_dev *pdev, int dev_idx)
debugf0("%s(): mci\n", __func__); debugf0("%s(): mci\n", __func__);
debugf0("Starting Probe1\n"); debugf0("Starting Probe1\n");
/* enable device 0 function 1 */ /* check to see if device 0 function 1 is enabled; if it isn't, we
* assume the BIOS has reserved it for a reason and is expecting
* exclusive access, we take care not to violate that assumption and
* fail the probe. */
pci_read_config_byte(pdev, E752X_DEVPRES1, &stat8); pci_read_config_byte(pdev, E752X_DEVPRES1, &stat8);
if (!force_function_unhide && !(stat8 & (1 << 5))) {
printk(KERN_INFO "Contact your BIOS vendor to see if the "
"E752x error registers can be safely un-hidden\n");
goto fail;
}
stat8 |= (1 << 5); stat8 |= (1 << 5);
pci_write_config_byte(pdev, E752X_DEVPRES1, stat8); pci_write_config_byte(pdev, E752X_DEVPRES1, stat8);
...@@ -1063,3 +1073,8 @@ module_exit(e752x_exit); ...@@ -1063,3 +1073,8 @@ module_exit(e752x_exit);
MODULE_LICENSE("GPL"); MODULE_LICENSE("GPL");
MODULE_AUTHOR("Linux Networx (http://lnxi.com) Tom Zimmerman\n"); MODULE_AUTHOR("Linux Networx (http://lnxi.com) Tom Zimmerman\n");
MODULE_DESCRIPTION("MC support for Intel e752x memory controllers"); MODULE_DESCRIPTION("MC support for Intel e752x memory controllers");
module_param(force_function_unhide, int, 0444);
MODULE_PARM_DESC(force_function_unhide, "if BIOS sets Dev0:Fun1 up as hidden:"
" 1=force unhide and hope BIOS doesn't fight driver for Dev0:Fun1 access");
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