Commit f4df73c2 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Thomas Gleixner

x86: add hpet sanity checks

Some BIOSes advertise HPET at 0x0. We really do no want to 
allocate a resource there. Check for it and leave early.

Other BIOSes tell us the HPET is at 0xfed0000000000000 
instead of 0xfed00000. Add a check and fix it up with a warning
on user request.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent bbbd9995
......@@ -637,6 +637,38 @@ static int __init acpi_parse_hpet(struct acpi_table_header *table)
}
hpet_address = hpet_tbl->address.address;
/*
* Some broken BIOSes advertise HPET at 0x0. We really do not
* want to allocate a resource there.
*/
if (!hpet_address) {
printk(KERN_WARNING PREFIX
"HPET id: %#x base: %#lx is invalid\n",
hpet_tbl->id, hpet_address);
return 0;
}
#ifdef CONFIG_X86_64
/*
* Some even more broken BIOSes advertise HPET at
* 0xfed0000000000000 instead of 0xfed00000. Fix it up and add
* some noise:
*/
if (hpet_address == 0xfed0000000000000UL) {
if (!hpet_force_user) {
printk(KERN_WARNING PREFIX "HPET id: %#x "
"base: 0xfed0000000000000 is bogus\n "
"try hpet=force on the kernel command line to "
"fix it up to 0xfed00000.\n", hpet_tbl->id);
hpet_address = 0;
return 0;
}
printk(KERN_WARNING PREFIX
"HPET id: %#x base: 0xfed0000000000000 fixed up "
"to 0xfed00000.\n", hpet_tbl->id);
hpet_address >>= 32;
}
#endif
printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
hpet_tbl->id, hpet_address);
......
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