Skip to content

Commit

Permalink
i2c: acpi: Do not instantiate I2C-clients on boards with known bogus …
Browse files Browse the repository at this point in the history
…DSDT entries

x86 ACPI devices which ship with only Android as their factory image
usually declare a whole bunch of bogus I2C devices in their ACPI tables.

Instantiating I2C clients for these bogus devices causes various issues,
e.g. GPIO/IRQ resource conflicts because sometimes drivers do bind to them.
The Android x86 kernel fork shipped on these devices has some special code
to remove these bogus devices, instead of just fixing the DSDT <sigh>.

Use the new acpi_quirk_skip_i2c_client_enumeration() helper to identify
known boards / acpi devices with this issue, and skip enumerating these.

Note these boards typically do actually have I2C devices, just
different ones then the ones described in their DSDT. The devices
which are actually present are manually instantiated by the
drivers/platform/x86/x86-android-tablets.c kernel module.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  • Loading branch information
Hans de Goede authored and Rafael J. Wysocki committed Dec 30, 2021
1 parent 35f9e77 commit a6e1445
Showing 1 changed file with 7 additions and 0 deletions.
7 changes: 7 additions & 0 deletions drivers/i2c/i2c-core-acpi.c
Original file line number Diff line number Diff line change
Expand Up @@ -254,6 +254,13 @@ static void i2c_acpi_register_device(struct i2c_adapter *adapter,
struct acpi_device *adev,
struct i2c_board_info *info)
{
/*
* Skip registration on boards where the ACPI tables are
* known to contain bogus I2C devices.
*/
if (acpi_quirk_skip_i2c_client_enumeration(adev))
return;

adev->power.flags.ignore_parent = true;
acpi_device_set_enumerated(adev);

Expand Down

0 comments on commit a6e1445

Please sign in to comment.