linux-kernel - Re: [PATCH] Input: ALPS - add support for 73 03 28 devices (Thinkpad L570)

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Date:   Tue, 27 Mar 2018 15:56:15 +0200
From:   Dennis Wassenberg <dennis.wassenberg@...unet.com>
To:     Pali Rohár <pali.rohar@...il.com>
CC:     Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Masaki Ota <masaki.ota@...alps.com>,
        Takashi Iwai <tiwai@...e.de>,
        Kees Cook <keescook@...omium.org>,
        Nir Perry <nirperry@...il.com>, <linux-input@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] Input: ALPS - add support for 73 03 28 devices (Thinkpad
 L570)

Hi,

oh ok, understood. Thanks for this hint.

So maybe there is something wrong with the alps_update_dual_info_ss4_v2
function or the reporting of the hardware.

alps_update_dual_info_ss4_v2 detects the ThinkPad L570 as ss4plus device
but not as dualpoint device. This means that the ALPS_DUALPOINT and the
ALPS_DUALPOINT_WITH_PRESSURE flag will not be set which results in a non
function trackstick and hardware mouse buttons. Each time I touch the
trackstick I get the message: "alps: Rejected trackstick packet from non
DualPoint device".

The value of otp[0][0] inside alps_update_dual_info_ss4_v2 is 0xCE. Are
there any ideas why it is not detected as dualpoint device?

Thank you & best regards,

Dennis

On 23.03.2018 15:33, Pali Rohár wrote:
> On Friday 23 March 2018 15:23:55 Dennis Wassenberg wrote:
>> The Lenovo Thinkpad L570 uses V8 protocol.
>> Add 0x73 0x03 0x28 devices to use V8 protovol which makes
>> trackstick and mouse buttons work with Lenovo Thinkpad L570.
>>
>> Signed-off-by: Dennis Wassenberg <dennis.wassenberg@...unet.com>
>> ---
>>  drivers/input/mouse/alps.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
>> index dbe57da..5523d4e 100644
>> --- a/drivers/input/mouse/alps.c
>> +++ b/drivers/input/mouse/alps.c
>> @@ -136,6 +136,8 @@
>>  	{ { 0x73, 0x02, 0x0a }, { ALPS_PROTO_V2, 0xf8, 0xf8, 0 } },
>>  	{ { 0x73, 0x02, 0x14 }, { ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_FW_BK_2 } },			/* Ahtec Laptop */
>>  	{ { 0x73, 0x02, 0x50 }, { ALPS_PROTO_V2, 0xcf, 0xcf, ALPS_FOUR_BUTTONS } },		/* Dell Vostro 1400 */
>> +	{ { 0x73, 0x03, 0x28 }, { ALPS_PROTO_V8, 0x18, 0x18,
>> +		ALPS_DUALPOINT | ALPS_DUALPOINT_WITH_PRESSURE | ALPS_BUTTONPAD } },		/* Lenovo L570 */
>>  };
>>  
>>  static const struct alps_protocol_info alps_v3_protocol_data = {
> 
> Hi! alps_model_data table is used for fixed identification of v1 and v2
> protocols. Why you need to add there v8 protocol which autodetection is
> already done in alps_identify() function? There is already code:
> 
> 		} else if (e7[0] == 0x73 && e7[1] == 0x03 &&
> 			   (e7[2] == 0x14 || e7[2] == 0x28)) {
> 			protocol = &alps_v8_protocol_data;
> 
> Which matches above your E7 detection 0x73, 0x03, 0x28.
> 
> Also you patch matches basically all v8 device and therefore has
> potential to break proper v8 autodetection for other v8 devices...
>