From: Tear <tarrqt@xxxxxxxxx> I have a Dell Optiplex GX240 and when I boot Linux, ACPI gets set up by only acpi=ht. dmesg shows the following line: DELL GX240 detected: force use of acpi=ht Everything seemed to be fine. However, I discovered that everything is not fine. The USB controller works so slowly that copying a few (uncached) 1 megabyte large photos from a USB-enabled digital camera takes many minutes instead of a couple of seconds. I am using Linux 2.6.21.1 on a Debian 4.0 ("Etch") system. I thought that this might be related to ACPI. So I tried to boot with _only_ "acpi=force" appended to the kernel command line. Voila, the USB controller started to work at full speed and copying photos from my digital camera took only seconds. I tested the system with "acpi=force" and could not find anything which did not work. I thought that this might be related to interrupts and APIC as well. (Note that this is APIC, not ACPI.) I tried booting with _only_ "noapic" and "nolapic" appended to the command line. Again, the USB controller started to work at full speed. Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Len Brown <len.brown@xxxxxxxxx> --- arch/i386/kernel/acpi/boot.c | 8 -------- 1 files changed, 0 insertions(+), 8 deletions(-) diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c index 280898b..a2c8b9e 100644 --- a/arch/i386/kernel/acpi/boot.c +++ b/arch/i386/kernel/acpi/boot.c @@ -971,14 +971,6 @@ static struct dmi_system_id __initdata acpi_dmi_table[] = { }, { .callback = force_acpi_ht, - .ident = "DELL GX240", - .matches = { - DMI_MATCH(DMI_BOARD_VENDOR, "Dell Computer Corporation"), - DMI_MATCH(DMI_BOARD_NAME, "OptiPlex GX240"), - }, - }, - { - .callback = force_acpi_ht, .ident = "HP VISUALIZE NT Workstation", .matches = { DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"), -- 1.5.3.rc2.22.g69a9b - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html