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

[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

drivers/edac/e752x_edac.c

+16 −1
Original line number Diff line number Diff line
@@ -25,6 +25,8 @@ 
#include <linux/slab.h>

#include "edac_mc.h"



static int force_function_unhide;



#define e752x_printk(level, fmt, arg...) \

	edac_printk(level, "e752x", fmt, ##arg)
@@ -782,8 +784,16 @@ static int e752x_probe1(struct pci_dev *pdev, int dev_idx) 
	debugf0("%s(): mci\n", __func__);

	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);

	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);

	pci_write_config_byte(pdev, E752X_DEVPRES1, stat8);
@@ -1063,3 +1073,8 @@ module_exit(e752x_exit); 
MODULE_LICENSE("GPL");

MODULE_AUTHOR("Linux Networx (http://lnxi.com) Tom Zimmerman\n");

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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