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

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

[Nikolai Kostrigin]

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@altlinux.org>
---
 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

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

[Benjamin Tissoires]

Hi Nikolai,

On Mon, Feb 8, 2021 at 9:01 AM Nikolai Kostrigin <nickel@altlinux.org> 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@altlinux.org>

Instead of downgrading the capabilities of the touchpad, couldn't we
fix the trackpoint issues?

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?

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
>

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

[Nikolai Kostrigin]

Hi, Benjamin!

08.02.2021 11:06, Benjamin Tissoires пишет:
> Hi Nikolai,
>
> On Mon, Feb 8, 2021 at 9:01 AM Nikolai Kostrigin <nickel@altlinux.org> 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@altlinux.org>
> 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