Hi,
03.03.2021 04:26, Dmitry Torokhov пишет:
> Hi Uwe,
>
> On Tue, Mar 02, 2021 at 10:09:34PM +0100, Uwe Kleine-König wrote:
>> Hello,
>>
>> I just installed Linux on a new Thinkpad E15 and I experience a
>> non-working touchpad. I can move the mouse just fine, but when I press
>> one of the three buttons or move the trackpoint the kernel log gets
>> flooded with:
>>
>> elan_i2c 0-0015: failed to read report data: -71
>>
>> and nothing happens in the GUI.
>>
>> This is a kernel from Debian testing, i.e. 5.10.13, during probe of the
>> device the following is reported:
>>
>> elan_i2c 0-0015: supply vcc not found, using dummy regulator
>> elan_i2c 0-0015: Elan Touchpad: Module ID: 0x000e, Firmware: 0x0001, Sample: 0x0000, IAP: 0x0000
>> input: Elan Touchpad as /devices/pci0000:00/0000:00:1f.4/i2c-0/0-0015/input/input21
>> input: Elan TrackPoint as /devices/pci0000:00/0000:00:1f.4/i2c-0/0-0015/input/input22
>>
>> I backported commits
>>
>> 056115daede8 Input: elan_i2c - add new trackpoint report type 0x5F
>> c7f0169e3bd2 Input: elan_i2c_core - move header inclusion inside
Uwe, you might miss
e4c9062717fe Input: elantech - fix protocol errors for some trackpoints
in SMBus mode
>>
>> to this kernel, but this didn't help.
>>
>> When enabling smbus tracing the matching events are:
>>
>> irq/159-elan_i2-2207 [003] .... 963.625641: smbus_read: i2c-0 a=015 f=0040 c=a8 BLOCK_DATA
>> irq/159-elan_i2-2207 [003] .... 963.629247: smbus_result: i2c-0 a=015 f=0000 c=a8 BLOCK_DATA rd res=-71
>>
>> The relevant code is:
>>
>> len = i2c_smbus_read_block_data(client,
>> ETP_SMBUS_PACKET_QUERY,
>> &report[ETP_SMBUS_REPORT_OFFSET]);
>> if (len < 0) {
>> dev_err(&client->dev, "failed to read report data: %d\n", len);
>> return len;
>> }
>>
>> I think the failing location in the i2c driver is
>>
>> if (read_write == I2C_SMBUS_READ ||
>> command == I2C_SMBUS_BLOCK_PROC_CALL) {
>> len = inb_p(SMBHSTDAT0(priv));
>> if (len < 1 || len > I2C_SMBUS_BLOCK_MAX)
>> return -EPROTO;
>>
>> data->block[0] = len;
>> for (i = 0; i < len; i++)
>> data->block[i + 1] = inb_p(SMBBLKDAT(priv));
>> }
>>
>> in i801_block_transaction_by_block().
>>
>> Does this ring a bell? Does someone know if there is documentation
>> available?
> I believe Nikolai also run into this issue and is saying that
>
> modprobe i2c_i801 disable_features=0x2
>
> cures the touchpad.
Yes, but the really rock solid solution is already in 5.11 (thanks to
Jingle and Dmitry):
https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=next&id=056115daede8d01f71732bc7d778fb85acee8eb6
https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=next&id=e4c9062717feda88900b566463228d1c4910af6d
which solves the issue for me as I mentioned in the original thread
>
> Thanks.
>
--
Best regards,
Nikolai Kostrigin
