Unfortunately some DSDTs issue bogus i2c reads to non existing devices
resulting in -EREMOTEIO errors because the non existing device of course
does not ack.
This happens e.g. from the The Asus T100TA's _BIX method, the DSDT on
the T100TA defines 2 resources on the I2C1 bus:
Name (EHID, ResourceTemplate ()
{
I2cSerialBusV2 (0x005B, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.I2C1",
0x00, ResourceConsumer, , Exclusive,
)
})
OperationRegion (EHOR, GenericSerialBus, Zero, 0x0100)
Field (EHOR, BufferAcc, NoLock, Preserve)
{
Connection (EHID),
Offset (0x01),
AccessAs (BufferAcc, AttribBytes (0x10)),
ABCD, 8
}
Name (UMPC, ResourceTemplate ()
{
I2cSerialBusV2 (0x0066, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.I2C1",
0x00, ResourceConsumer, , Exclusive,
)
})
The _BIX method does a single read (on each BIX() call) from the EHID
device through the ABCD Field, only to completely ignore the result.
This read always fails as there is no i2c client at address 0x5b.
The _BIX method also does several reads from the UMPC device and actually
uses the results of those to provide battery information.
IIRC I've also seen some DSTDs which do an i2c read to detect if a device
is present, also leading to false positive errors being logged.
Esp. the _BIX use is problematic as the _BIX method gets called
periodically to monitor battery status.
This commit stops the logs from filling up with errors like these:
[ 57.327858] i2c i2c-0: i2c read 16 bytes from client@0x5b starting at
reg 0x1 failed, error: -121
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When we get an error doing an ACPI SerialBus I2C OpRegion read log some
useful details, like the client address and which register is being
read.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
For now empty ID table is not allowed with ACPI and prevents driver to
be probed.
Add a check to allow empty ID table.
This introduces a helper i2c_acpi_match_device().
Note, we rename some static function in i2c-core-acpi.c to distinguish
with public API.
Fixes: da10c06a04 ("i2c: Make I2C ID tables non-mandatory for DT'ed devices")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Rajmohan Mani <rajmohan.mani@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[wsa: needed to get some drivers probed again]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>
Removes some ifdeffery. Also add the new file to the relevant
MAINTAINERS section.
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
