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
>
> 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.
Thanks.
--
Dmitry
