Comment 128 for bug 755791

2.6.32 with pci=nomsi:

It's "bad". irq # 19 count is frozen. glxgears draws, but the FPS is reduced 70, while without "nomsi" it was 240. Xorg log is the same. dmesg is same except "irq for nomsi".

I haven't reported this before, but when it's "bad", redraw of my x terminal, urxvt, is snail-slow, and I saw it with "nomsi", too. (I don't need opengl, so this is the biggest trouble for me.)

3.0.4: no much difference with pci=nomsi, it's anyway bad. (In 2.6.39 and 3.0.4, in most cases glxgears is not drawn, showing only black box. But in 2.6.32, every time I tried gears were drawn even with nomsi, but the test is not thorough.)

Most of dmesg differences are trivial, but I quote one hunk here FYI:
------------------------------------------------------------------------
--- dmesg-3.0.4 2011-10-18 17:02:54.743566206 +0900
+++ dmesg-3.0.4-nomsi 2011-10-18 16:57:38.871537255 +0900
@@ -268,9 +266,7 @@
 ACPI: PCI Interrupt Routing Table [\_SB_.C08B._PRT]
 ACPI: PCI Interrupt Routing Table [\_SB_.C08B.C08C._PRT]
 ACPI: PCI Interrupt Routing Table [\_SB_.C08B.C0FC._PRT]
- pci0000:00: Requesting ACPI _OSC control (0x1d)
- pci0000:00: ACPI _OSC request failed (AE_NOT_FOUND), returned control mask: 0x1d
-ACPI _OSC control for PCIe not granted, disabling ASPM
+ pci0000:00: Unable to request _OSC control (_OSC support mask: 0x0f)
 ACPI: PCI Interrupt Link [C145] (IRQs 10 11) *0, disabled.
 ACPI: PCI Interrupt Link [C146] (IRQs 10 11) *0, disabled.
 ACPI: PCI Interrupt Link [C147] (IRQs 10 11) *0, disabled.
------------------------------------------------------------------------