Re: [PATCH] x86: Add Dell E5420 reboot quirk

[Daniel J Blueman]

On 13 May 2011 10:44, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> Daniel J Blueman <daniel.blueman@xxxxxxxxx> wrote:
>> Rebooting on the Dell E5420 often hangs with the keyboard method, but is
>> reliable via the PCI method. Signed-off-by: Daniel J Blueman
>> <daniel.blueman@xxxxxxxxx> --- arch/x86/kernel/reboot.c | 8 ++++++++ 1 files
>> changed, 8 insertions(+), 0 deletions(-) diff --git
>> a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 08c44b0..b16032d
>> 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@
>> -411,6 +411,14 @@ static struct dmi_system_id __initdata
>> pci_reboot_dmi_table[] = { DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"), }, }, + {
>> + .callback = set_pci_reboot, + .ident = "Dell Latitude E5420", + .matches =
>> { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME,
>> "Latitude E5420"), + }, + }, { } }; -- 1.7.4.1

> How does it work with ACPI?

All other reboot methods including ACPI are unreliable and seem to
demonstrate the same failure probability; PCI is the only reliable
method alas.

I guess the ACPI reboot method is the supported 'official' vector (and
is what Windows uses [1]), so there must be some other constraints
preventing it work as expected, unless the ACPI tables delivered to
Linux are broken, would you say?

Daniel

[1] http://comments.gmane.org/gmane.linux.kernel/1122388
-- 
Daniel J Blueman
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