[PATCH] x86: Fix verify_quirk_intel_irqbalance()
Fix verify_quirk_intel_irqbalance(). genapic checks should really
happen only on affected versions of the E7520/E7320/E7525 based platforms.
AK: This should akpm's Coyote SDV
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/arch/i386/kernel/quirks.c b/arch/i386/kernel/quirks.c
index a01320a..34874c3 100644
--- a/arch/i386/kernel/quirks.c
+++ b/arch/i386/kernel/quirks.c
@@ -10,13 +10,38 @@
#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
static void __devinit verify_quirk_intel_irqbalance(struct pci_dev *dev)
{
+ u8 config, rev;
+ u32 word;
+
+ /* BIOS may enable hardware IRQ balancing for
+ * E7520/E7320/E7525(revision ID 0x9 and below)
+ * based platforms.
+ * For those platforms, make sure that the genapic is set to 'flat'
+ */
+ pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev);
+ if (rev > 0x9)
+ return;
+
+ /* enable access to config space*/
+ pci_read_config_byte(dev, 0xf4, &config);
+ pci_write_config_byte(dev, 0xf4, config|0x2);
+
+ /* read xTPR register */
+ raw_pci_ops->read(0, 0, 0x40, 0x4c, 2, &word);
+
+ if (!(word & (1 << 13))) {
#ifdef CONFIG_X86_64
- if (genapic != &apic_flat)
- panic("APIC mode must be flat on this system\n");
+ if (genapic != &apic_flat)
+ panic("APIC mode must be flat on this system\n");
#elif defined(CONFIG_X86_GENERICARCH)
- if (genapic != &apic_default)
- panic("APIC mode must be default(flat) on this system. Use apic=default\n");
+ if (genapic != &apic_default)
+ panic("APIC mode must be default(flat) on this system. Use apic=default\n");
#endif
+ }
+
+ /* put back the original value for config space*/
+ if (!(config & 0x2))
+ pci_write_config_byte(dev, 0xf4, config);
}
void __init quirk_intel_irqbalance(void)