Re: [PATCH] ACPI: scan: Ignore MAGN0001

From: Marius Hoch
Date: Sat Apr 22 2023 - 12:48:03 EST


Hi Hans,

On 21/04/2023 20:07, Hans de Goede wrote:
Hi Marius,

On 4/21/23 18:27, Marius Hoch wrote:
The LSM303D on the Lenovo Yoga Tablet 2 series is present
as both ACCL0001 and MAGN0001. As we can only ever register an
i2c client for one of them, ignore MAGN0001.

Currently this errors:
i2c i2c-4: Failed to register i2c client MAGN0001:00 at 0x1d (-16)

Tested on a Lenovo Yoga Tablet 2 1051-F.

Signed-off-by: Marius Hoch <mail@xxxxxxxxxxxxx>
By adding the HID to the ignore_serial_bus_ids[] list, you are
causing the ACPI code to instead instantiate a platform_device
for it.

This will successfully silence the error you are trying to silence,
but I don't think it really is what you intent / want to do ?
It is not, no. Given we will only ever care for ACCL0001, we can entirely skip MAGN0001.

IMHO it would be better to add a NOT_PRESENT_ENTRY_HID() entry
to the override_status_ids[] table in drivers/acpi/x86/utils.c,
this will override the return of _STA, causing neither a
platform_device not an i2c_client to get instantiated for
the duplicate MAGN0001 device.
That sounds much better, thanks for the pointer!
I've send a new patch (20230422164401.5986-1-mail@xxxxxxxxxxxxx).

Cheers,
Marius

(please keep the comment above the entry why the entry is there)

Regards,

Hans







---
drivers/acpi/scan.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 0c6f06abe3f4..d21c411e9719 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1730,6 +1730,12 @@ static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
*/
{"BCM4752", },
{"LNV4752", },
+ /*
+ * The LSM303D on the Lenovo Yoga Tablet 2 series is present
+ * as both ACCL0001 and MAGN0001. As we can only ever register an
+ * i2c client for one of them, ignore MAGN0001.
+ */
+ {"MAGN0001", },
{}
};

base-commit: cb0856346a60fe3eb837ba5e73588a41f81ac05f