Merge branch 'timers-for-linus-hpet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-for-linus-hpet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, hpet: Add reference to chipset erratum documentation for disable-hpet-msi-quirk x86, hpet: Restrict read back to affected ATI chipsets
This commit is contained in:
commit
6fa0fddd5f
3 changed files with 26 additions and 12 deletions
|
@ -68,6 +68,7 @@ extern unsigned long force_hpet_address;
|
||||||
extern u8 hpet_blockid;
|
extern u8 hpet_blockid;
|
||||||
extern int hpet_force_user;
|
extern int hpet_force_user;
|
||||||
extern u8 hpet_msi_disable;
|
extern u8 hpet_msi_disable;
|
||||||
|
extern u8 hpet_readback_cmp;
|
||||||
extern int is_hpet_enabled(void);
|
extern int is_hpet_enabled(void);
|
||||||
extern int hpet_enable(void);
|
extern int hpet_enable(void);
|
||||||
extern void hpet_disable(void);
|
extern void hpet_disable(void);
|
||||||
|
|
|
@ -36,6 +36,7 @@
|
||||||
unsigned long hpet_address;
|
unsigned long hpet_address;
|
||||||
u8 hpet_blockid; /* OS timer block num */
|
u8 hpet_blockid; /* OS timer block num */
|
||||||
u8 hpet_msi_disable;
|
u8 hpet_msi_disable;
|
||||||
|
u8 hpet_readback_cmp;
|
||||||
|
|
||||||
#ifdef CONFIG_PCI_MSI
|
#ifdef CONFIG_PCI_MSI
|
||||||
static unsigned long hpet_num_timers;
|
static unsigned long hpet_num_timers;
|
||||||
|
@ -395,19 +396,23 @@ static int hpet_next_event(unsigned long delta,
|
||||||
* at that point and we would wait for the next hpet interrupt
|
* at that point and we would wait for the next hpet interrupt
|
||||||
* forever. We found out that reading the CMP register back
|
* forever. We found out that reading the CMP register back
|
||||||
* forces the transfer so we can rely on the comparison with
|
* forces the transfer so we can rely on the comparison with
|
||||||
* the counter register below. If the read back from the
|
* the counter register below.
|
||||||
* compare register does not match the value we programmed
|
*
|
||||||
* then we might have a real hardware problem. We can not do
|
* That works fine on those ATI chipsets, but on newer Intel
|
||||||
* much about it here, but at least alert the user/admin with
|
* chipsets (ICH9...) this triggers due to an erratum: Reading
|
||||||
* a prominent warning.
|
* the comparator immediately following a write is returning
|
||||||
* An erratum on some chipsets (ICH9,..), results in comparator read
|
* the old value.
|
||||||
* immediately following a write returning old value. Workaround
|
*
|
||||||
* for this is to read this value second time, when first
|
* We restrict the read back to the affected ATI chipsets (set
|
||||||
* read returns old value.
|
* by quirks) and also run it with hpet=verbose for debugging
|
||||||
|
* purposes.
|
||||||
*/
|
*/
|
||||||
if (unlikely((u32)hpet_readl(HPET_Tn_CMP(timer)) != cnt)) {
|
if (hpet_readback_cmp || hpet_verbose) {
|
||||||
WARN_ONCE(hpet_readl(HPET_Tn_CMP(timer)) != cnt,
|
u32 cmp = hpet_readl(HPET_Tn_CMP(timer));
|
||||||
KERN_WARNING "hpet: compare register read back failed.\n");
|
|
||||||
|
if (cmp != cnt)
|
||||||
|
printk_once(KERN_WARNING
|
||||||
|
"hpet: compare register read back failed.\n");
|
||||||
}
|
}
|
||||||
|
|
||||||
return (s32)(hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
|
return (s32)(hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
|
||||||
|
|
|
@ -495,10 +495,18 @@ void force_hpet_resume(void)
|
||||||
/*
|
/*
|
||||||
* HPET MSI on some boards (ATI SB700/SB800) has side effect on
|
* HPET MSI on some boards (ATI SB700/SB800) has side effect on
|
||||||
* floppy DMA. Disable HPET MSI on such platforms.
|
* floppy DMA. Disable HPET MSI on such platforms.
|
||||||
|
* See erratum #27 (Misinterpreted MSI Requests May Result in
|
||||||
|
* Corrupted LPC DMA Data) in AMD Publication #46837,
|
||||||
|
* "SB700 Family Product Errata", Rev. 1.0, March 2010.
|
||||||
|
*
|
||||||
|
* Also force the read back of the CMP register in hpet_next_event()
|
||||||
|
* to work around the problem that the CMP register write seems to be
|
||||||
|
* delayed. See hpet_next_event() for details.
|
||||||
*/
|
*/
|
||||||
static void force_disable_hpet_msi(struct pci_dev *unused)
|
static void force_disable_hpet_msi(struct pci_dev *unused)
|
||||||
{
|
{
|
||||||
hpet_msi_disable = 1;
|
hpet_msi_disable = 1;
|
||||||
|
hpet_readback_cmp = 1;
|
||||||
}
|
}
|
||||||
|
|
||||||
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS,
|
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS,
|
||||||
|
|
Reference in a new issue