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authorHans de Goede <hdegoede@redhat.com>2017-07-04 15:04:48 +0200
committerWolfram Sang <wsa@the-dreams.de>2017-07-04 15:57:34 +0200
commit3a4991a9864cb6b98bb9c7cf47854ffe2a79805a (patch)
treeca03be91e4c224df47b89fe3a565caf6ec605436 /drivers/i2c/i2c-core-acpi.c
parent5b6d721b266acaef411520e28066e4624c6619e7 (diff)
i2c: acpi: Do not create i2c-clients for LNXVIDEO ACPI devices
ACPI video devices get tagged by the kernel with the custom LNXVIDEO HID so that normal pnp-id matching can be used and are handled by the acpi-video driver. Sometimes the ACPI nodes describing these contain a SERIAL_TYPE_I2C ACPI resource. Before this commit the presence of this resource would cause the i2c-core to create a /sys/bus/i2c/devices/i2c-LNXVIDEO:00 device for this with a modalias of: "i2c:LNXVIDEO:00". There is no i2c driver for this custom HID, the acpi-video driver binds directly to the ACPI device /sys/bus/acpi/devices/LNXVIDEO\:00 which has a modalias of "acpi:LNXVIDEO:" . Not only is the creation of an i2c-client for this undesirable, it is actually causing problems. This weird pseudo-resource claims an i2c speed of 100KHz and typically points to the i2c bus which is used by the touchscreen controller. Some touchscreen controllers only work properly at 400KHz, at 100KHz they cause errors like these: i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration silead_ts i2c-MSSL1680:00: Registers clear error -11 This commit makes the i2c-core ignore LNXVIDEO compatible ACPI devices which has 2 positive results: 1) The bogus i2c-client for these is no longer created. 2) i2c_acpi_lookup_speed now ignores the 100KHz speed from the pseudo i2c-resouce and properly returns 400KHz as speed for the touchscreen i2c bus, fixing the touchscreen not working on various devies. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/i2c-core-acpi.c')
-rw-r--r--drivers/i2c/i2c-core-acpi.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 052005579ed6..4842ec3a5451 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -76,6 +76,15 @@ static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
return 1;
}
+static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
+ /*
+ * ACPI video acpi_devices, which are handled by the acpi-video driver
+ * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.
+ */
+ { ACPI_VIDEO_HID, 0 },
+ {}
+};
+
static int i2c_acpi_do_lookup(struct acpi_device *adev,
struct i2c_acpi_lookup *lookup)
{
@@ -87,6 +96,9 @@ static int i2c_acpi_do_lookup(struct acpi_device *adev,
acpi_device_enumerated(adev))
return -EINVAL;
+ if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
+ return -ENODEV;
+
memset(info, 0, sizeof(*info));
lookup->device_handle = acpi_device_handle(adev);

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