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ACPI / scan: set status to 0 if _STA failed

PATCH Applied Aaron Lu 4 participants 4 messages Nov 19, 2015 – Dec 14, 2015 1 message not in the archive

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Aaron Lu

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#0 lore raw

PATCH 1/1 ACPI / scan: set status to 0 if _STA failed

Some ACPI node's _STA will touch operation region field, since the evaluation of _STA in acpi_bus_type_and_status is very early, the operation region handler is not ready yet. Instead of fail that function and not creating the acpi_device node consequently, set status to 0 so that later when the driver for that device is probing, it can find the acpi_device node and proceed normally. And at that time, the handler for the operation region is ready and its _STA evaluation will succeed, its present status can be checked there.

Even there will be no driver using this node later, it doesn't seem hurt to have one more acpi_device node created with status set to 0.

This happens on Microsoft Surface 3, where the SPI device node NTRG's _STA touches GPIO fields and the SPI core driver will only enumerate SPI devices from ACPI if the acpi_device node is 1: created; 2: _STA indicates it's present.

Note that due to another problem in SPI driver, for NTRG to be actually enumerated, some changes have to be made in the SPI layer, which is addressed by Mika(not send out yet):
https://bugzilla.kernel.org/show_bug.cgi?id=104291#c23

Buglink https://bugzilla.kernel.org/show_bug.cgi?id=104291
Reported-by Bastien Nocera <[email protected]>
Signed-off-by Aaron Lu <[email protected]>
---
 drivers/acpi/scan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/acpi/scan.c +1 -1
index 78d5f02a073b..ddfed0d407e5 100644
@@ -1461,7 +1461,7 @@ static int acpi_bus_type_and_status(acpi_handle handle, int *type,
 		*type = ACPI_BUS_TYPE_DEVICE;
 		status = acpi_bus_get_status_handle(handle, sta);
 		if (ACPI_FAILURE(status))
-			return -ENODEV;
+			*sta = 0;
 		break;
 	case ACPI_TYPE_PROCESSOR:
 		*type = ACPI_BUS_TYPE_PROCESSOR;
Signature · 6 lines
2.5.0

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Reviewed-by on v1 1/1
#1 lore raw
Quoted 17 lines · Aaron Lu

Some ACPI node's _STA will touch operation region field, since the evaluation of _STA in acpi_bus_type_and_status is very early, the operation region handler is not ready yet. Instead of fail that function and not creating the acpi_device node consequently, set status to 0 so that later when the driver for that device is probing, it can find the acpi_device node and proceed normally. And at that time, the handler for the operation region is ready and its _STA evaluation will succeed, its present status can be checked there.

Even there will be no driver using this node later, it doesn't seem hurt to have one more acpi_device node created with status set to 0.

This happens on Microsoft Surface 3, where the SPI device node NTRG's _STA touches GPIO fields and the SPI core driver will only enumerate SPI devices from ACPI if the acpi_device node is 1: created; 2: _STA indicates it's present.

Quoted 8 lines

Note that due to another problem in SPI driver, for NTRG to be actually enumerated, some changes have to be made in the SPI layer, which is addressed by Mika(not send out yet):
https://bugzilla.kernel.org/show_bug.cgi?id=104291#c23

Buglink https://bugzilla.kernel.org/show_bug.cgi?id=104291
Reported-by Bastien Nocera <[email protected]>
Signed-off-by Aaron Lu <[email protected]>

I don't know any better solution to this,

Reviewed-by Mika Westerberg <[email protected]>
Tested-by on v1 1/1
#4 lore raw
In reply to Aaron Lu
Quoted 27 lines · Aaron Lu

Some ACPI node's _STA will touch operation region field, since the evaluation of _STA in acpi_bus_type_and_status is very early, the operation region handler is not ready yet. Instead of fail that function
and not creating the acpi_device node consequently, set status to 0 so
that later when the driver for that device is probing, it can find the acpi_device node and proceed normally. And at that time, the handler for the operation region is ready and its _STA evaluation will
succeed, its present status can be checked there.

Even there will be no driver using this node later, it doesn't seem hurt to have one more acpi_device node created with status set to 0.

This happens on Microsoft Surface 3, where the SPI device node NTRG's _STA touches GPIO fields and the SPI core driver will only enumerate SPI
devices from ACPI if the acpi_device node is 1: created; 2: _STA indicates it's present.

Note that due to another problem in SPI driver, for NTRG to be actually
enumerated, some changes have to be made in the SPI layer, which is addressed by Mika(not send out yet):
https://bugzilla.kernel.org/show_bug.cgi?id=104291#c23

Quoted 3 lines
Buglink https://bugzilla.kernel.org/show_bug.cgi?id=104291
Reported-by Bastien Nocera <[email protected]>
Signed-off-by Aaron Lu <[email protected]>

Worked for me with the additional SPI patch on a Surface 3.

Tested-by Bastien Nocera <[email protected]>
Applied
#3 lore raw
In reply to a message not in the archive
Quoted 23 lines · Mika Westerberg
Quoted 22 lines · Aaron Lu

Some ACPI node's _STA will touch operation region field, since the evaluation of _STA in acpi_bus_type_and_status is very early, the operation region handler is not ready yet. Instead of fail that function and not creating the acpi_device node consequently, set status to 0 so that later when the driver for that device is probing, it can find the acpi_device node and proceed normally. And at that time, the handler for the operation region is ready and its _STA evaluation will succeed, its present status can be checked there.

Even there will be no driver using this node later, it doesn't seem hurt to have one more acpi_device node created with status set to 0.

This happens on Microsoft Surface 3, where the SPI device node NTRG's _STA touches GPIO fields and the SPI core driver will only enumerate SPI devices from ACPI if the acpi_device node is 1: created; 2: _STA indicates it's present.

Note that due to another problem in SPI driver, for NTRG to be actually enumerated, some changes have to be made in the SPI layer, which is addressed by Mika(not send out yet):
https://bugzilla.kernel.org/show_bug.cgi?id=104291#c23

Quoted 7 lines
Quoted 3 lines
Buglink https://bugzilla.kernel.org/show_bug.cgi?id=104291
Reported-by Bastien Nocera <[email protected]>
Signed-off-by Aaron Lu <[email protected]>

I don't know any better solution to this,

Reviewed-by Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/[email protected]>

Applied, thanks!

Rafael

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