Re: [PATCH] Input: elantech - add LEN2146 to SMBus blacklist for ThinkPad L13 Gen2

From: Nikolai Kostrigin
Date: Mon Feb 08 2021 - 04:13:50 EST


Hi, Benjamin!

08.02.2021 11:06, Benjamin Tissoires пишет:
> Hi Nikolai,
>
> On Mon, Feb 8, 2021 at 9:01 AM Nikolai Kostrigin <nickel@xxxxxxxxxxxx> wrote:
>> ThinkPad L13 Gen2 has both touchpad and trackpoint.
>> PNP: LEN2146 PNP0f13
>> With the default protocol (elantech-smbus) trackpoint is not operating,
>> while touchpad does. Changing to elantech renders both operational.
>>
>> Signed-off-by: Nikolai Kostrigin <nickel@xxxxxxxxxxxx>
> Instead of downgrading the capabilities of the touchpad, couldn't we
> fix the trackpoint issues?
Yes, I consider fixing the issue would be better than downgrading
touchpad capabilities.
Blacklisting was the first and most obvious idea to test.

I'm eager to perform additional diagnostics to choose a better solution.
Your advice would be appreciated.

>
> I am surprised elantech doesn't work with the trackpoint, because I am
> pretty sure I wrote patches in that regard. Which kernel version have
> you been testing?
The patch was tested with 5.10.13 only, but the trackpoint behaviour is
the same on 5.4.92.
> Cheers,
> Benjamin
>

>
>> ---
>> drivers/input/mouse/elantech.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
>> index 90f8765f9efc..c4c3fa5828d8 100644
>> --- a/drivers/input/mouse/elantech.c
>> +++ b/drivers/input/mouse/elantech.c
>> @@ -1776,6 +1776,7 @@ static const char * const i2c_blacklist_pnp_ids[] = {
>> * These are known to not be working properly as bits are missing
>> * in elan_i2c.
>> */
>> + "LEN2146", /* ThinkPad L13 Gen2 */
>> NULL
>> };
>>
>> --
>> 2.29.2
>>
--
Best regards,
Nikolai Kostrigin