Re: [PATCH] Input: alps - Demystify trackstick initialization for v3 and v6 protocols

Great, thank you. Enabling that RAW/extended/SP4 mode is done by
sequence E6, E6, E6, F3, C8, F3, 14 (written in page 35) and it matches
what function alps_trackstick_enter_extended_mode_v3_v6() in my patch is
doing. So is correct.

On page 36 I see that there is described Method 1 for reporting stick
data which prevents cursor jumps. Seems that kernel uses Method 2.
Method 1 depends on some prioritization.

Do you have some information how to activate Method 1? Sometimes I
observe that problem with "cursor jumps" and from Method 1 could prevent
it. So I would like to try experimenting...

On Wednesday 14 March 2018 23:56:46 Masaki Ota wrote:

Hi, Pali,

I have added Appendix.
According to this spec documents, SP raw mode is SP 4 byte mode.
I think Extended mode meaning is almost all the same as Raw mode.
The description of how to set is written in Page 35.

Best Regards,
Masaki Ota
-----Original Message-----
From: Pali Rohár [mailto:pali.rohar@gmail.com] 
Sent: Thursday, March 15, 2018 7:58 AM
To: 太田 真喜 Masaki Ota <redacted>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>; linux-input@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Input: alps - Demystify trackstick initialization for v3 and v6 protocols

Hi! Thank you for information.

Your PS/2 Aux Port Control description seems to really matches. Just there is reverse order of bits. Bit 0 in description is highest, therefore matches BIT(7) macro.

Bit 6 in description (BIT(1) in code) describes SP Extended Mode which alps.c enabled. And in that description is written:

"If 1 SP is extended packet format (driver must set SP raw mode and GP absolute mode)."

Do you have any idea what "SP raw mode" is? How to set it? For me it looks like it could be that extended mode of trackstick itself.

"GP absolute mode" I guess is GlidePoint absolute mode, therefore enable
6 byte absolute mode for touchpad.

And for Bit 7 (BIT(0)) is written:

This bit is used with the PS/2 Aux port to use the Pass-Thru mode ( see appendix A ). Do you have some information about this appendix A?

On Wednesday 14 March 2018 10:21:43 Masaki Ota wrote:

quoted

Hi, Pali,

I just picked up the spec which relates with trackstic.

Best Regards,
Masaki Ota
-----Original Message-----
From: Pali Rohár [mailto:pali.rohar@gmail.com]
Sent: Tuesday, March 13, 2018 8:14 AM
To: 太田 真喜 Masaki Ota <redacted>; Dmitry Torokhov 
[off-list ref]
Cc: linux-input@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Input: alps - Demystify trackstick initialization 
for v3 and v6 protocols

Masaki, if you have access to the internal ALPS v3 / Rushmore 
documentation, I would like to have a review of this patch or 
confirmation of those information :-)

--
Pali Rohár
pali.rohar@gmail.com

-- 
Pali Rohár
pali.rohar@gmail.com