: ACPI: Add the dmi check to make acpi_enforce_resources strict

PATCH Matthew Garrett 3 participants 3 messages Mar 10, 2009 – Apr 2, 2009 1 message not in the archive ACPI

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Matthew Garrett

author

2009-03-10 12:39 UTC #1 lore raw

Quoted 10 lines · yakui_zhao

Subject: ACPI: Add the dmi check to make acpi_enforce_resources strict
From: Zhao Yakui <[email protected]>
On some boxes the SMBus PCI controller is not hidden. The SMbus I/O port
will be accessed in AML code. If the i2c driver is still loaded for the SMbus PCI device, there is no synchronization between OS and BIOS. And the conflict will happen.
So the dmi check is added so that the acpi_enforce_resources is strict when
the box falls into the dmi check table. In such case the i2c driver won't be loaded for the SMbus pci device.

I think the only safe behaviour here is to default to strict on all hardware.

Signature · 1 line

Matthew Garrett | [email protected]

Zhang Rui

2009-03-11 02:33 UTC #2 lore raw

Quoted 12 lines · Matthew Garrett

Quoted 10 lines · yakui_zhao
Subject: ACPI: Add the dmi check to make acpi_enforce_resources strict
From: Zhao Yakui <[email protected]>
On some boxes the SMBus PCI controller is not hidden. The SMbus I/O port
will be accessed in AML code. If the i2c driver is still loaded for the SMbus PCI device, there is no synchronization between OS and BIOS. And the conflict will happen.
So the dmi check is added so that the acpi_enforce_resources is strict when
the box falls into the dmi check table. In such case the i2c driver won't be loaded for the SMbus pci device.

Quoted 3 lines

I think the only safe behaviour here is to default to strict on all hardware.

we've discussed this with Len,
he thinks that we should first generate a DMI patch to fix the eeepc901 regression, which can be shipped upstream soon.
then we'll cook up another patch, to set acpi_enforce_resources=strict by default, which should be shipped to len's test tree first, and see if there are any objections from the SMBus driver side.

Yakui will send the second patch out soon.

thanks,
rui.

Len Brown

reviewer

2009-04-02 21:19 UTC #3 lore raw

Quoted 16 lines · Zhang Rui

Quoted 12 lines · Matthew Garrett
Quoted 10 lines · yakui_zhao
Subject: ACPI: Add the dmi check to make acpi_enforce_resources strict
From: Zhao Yakui <[email protected]>
On some boxes the SMBus PCI controller is not hidden. The SMbus I/O port
will be accessed in AML code. If the i2c driver is still loaded for the SMbus PCI device, there is no synchronization between OS and BIOS. And the conflict will happen.
So the dmi check is added so that the acpi_enforce_resources is strict when
the box falls into the dmi check table. In such case the i2c driver won't be loaded for the SMbus pci device.
Quoted 3 lines
I think the only safe behaviour here is to default to strict on all hardware.

Quoted 8 lines

we've discussed this with Len,
he thinks that we should first generate a DMI patch to fix the eeepc901 regression, which can be shipped upstream soon.
then we'll cook up another patch, to set acpi_enforce_resources=strict by default, which should be shipped to len's test tree first, and see if there are any objections from the SMBus driver side.
Yakui will send the second patch out soon.

I agree with Matthew.

What I asked for what the DMI patch first -- something we could send to .29 and .stable w/ minimum risk.

Then (later) on top of that...
a patch to make the DMI unnecessary and switch the
default -- something we can revert upstream if it turns into a disaster.

at this point, "later" is "now":-)

So I'm going to dump the DMI patch and apply Luca's patch for 2.6.30.

for 2.6.29 we can either go low risk (dmi patch) or change the default after it cooks in 2.6.30 for a bit.

thanks,
-Len