linux-kernel - Re: [PATCH] Input: elan_i2c - add ASUS EeeBook X205TA special touchpad fw

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Date:   Tue, 7 Mar 2017 11:51:56 +0100
From:   Matjaž Hegedič <matjaz.hegedic@...il.com>
To:     廖崇榮 <kt.liao@....com.tw>,
        'Dmitry Torokhov' <dmitry.torokhov@...il.com>
Cc:     linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
        黃世鵬 經理 <phoenix@....com.tw>,
        miller_wang@....com.tw
Subject: Re: [PATCH] Input: elan_i2c - add ASUS EeeBook X205TA special
 touchpad fw

Hi Dmitry, KT!

On 2017-03-07 08:05, 廖崇榮 wrote:
> Hi Dmitry
>
> -----Original Message-----
> From: Dmitry Torokhov [mailto:dmitry.torokhov@...il.com]
> Sent: Tuesday, March 07, 2017 3:55 AM
> To: KT Liao
> Cc: linux-input@...r.kernel.org; linux-kernel@...r.kernel.org; Matjaz
> Hegedic
> Subject: Re: [PATCH] Input: elan_i2c - add ASUS EeeBook X205TA special
> touchpad fw
>
> On Sun, Mar 05, 2017 at 03:13:02AM +0100, Matjaz Hegedic wrote:
>> EeeBook X205TA is yet another ASUS device with a special touchpad
>> firmware that needs to be accounted for during initialization, or else
>> the touchpad will go into an invalid state upon suspend/resume.
>> Adding the appropriate ic_type and product_id check fixes the problem.
>
> KT, does this look reasonable? Are there more ASUS models that need such
> handling?
> [KT] : I just discuss it with FW team.
> We can't confirm it right now because it's an old product. And the solution
> focus on power-on issue, not suspend/resume.
> I will let you know once we figure it out.
>
> Our FW has modified, the issue should not happen on new models.
>
> Thanks		KT

As it is now, the touchpad will stop working upon resume, returning an
invalid id (and requires a cumbersome workaround of reloading the 
module). As the touchpad FW is opaque to me, the only way I could 
resolve the bug was through trial-and-error. Including the touchpad in 
the 'special fw' resolves the bug and the touchpad resumes without issue.

Now, even if the function is indeed used to resolve a different issue on 
other ASUS touchpads, I would argue that this is the most pragmatic way 
of resolving the problem on X205TA, X205TAW and F205TA (and possibly 
also X200HA & X206HA, though I don't have those to test).

It shouldn't affect any other models or touchpad products.

Thanks!

>>
>> Signed-off-by: Matjaz Hegedic <matjaz.hegedic@...il.com>
>> ---
>>  drivers/input/mouse/elan_i2c_core.c | 22 ++++++++++++----------
>>  1 file changed, 12 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/input/mouse/elan_i2c_core.c
>> b/drivers/input/mouse/elan_i2c_core.c
>> index 2c7d287..dde3ad7 100644
>> --- a/drivers/input/mouse/elan_i2c_core.c
>> +++ b/drivers/input/mouse/elan_i2c_core.c
>> @@ -218,17 +218,19 @@ static int elan_query_product(struct
>> elan_tp_data *data)
>>
>>  static int elan_check_ASUS_special_fw(struct elan_tp_data *data)  {
>> -	if (data->ic_type != 0x0E)
>> -		return false;
>> -
>> -	switch (data->product_id) {
>> -	case 0x05 ... 0x07:
>> -	case 0x09:
>> -	case 0x13:
>> -		return true;
>> -	default:
>> -		return false;
>> +	if (data->ic_type == 0x0E) {
>> +		switch (data->product_id) {
>> +		case 0x05 ... 0x07:
>> +		case 0x09:
>> +		case 0x13:
>> +			return true;
>> +		}
>>  	}
>> +	/* ASUS EeeBook X205TA */
>> +	else if (data->ic_type == 0x8 && data->product_id == 0x26)
>> +		return true;
>> +
>> +	return false;
>>  }
>>
>>  static int __elan_initialize(struct elan_tp_data *data)
>> --
>> 2.7.4
>>
>
> Thanks.
>