linux-kernel - Re: [REGRESSION] Touchpad failure after e7348396c6d5 ("Input: ALPS

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Date:   Mon, 19 Jun 2017 19:20:26 -0400
From:   Paul Donohue <linux-kernel@...lSD.com>
To:     Laura Abbott <labbott@...hat.com>
Cc:     Masaki Ota <masaki.ota@...alps.com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Pali Rohar <pali.rohar@...il.com>,
        Nick Fletcher <nick.m.fletcher@...il.com>,
        "linux-input@...r.kernel.org" <linux-input@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "scott.s.lowe@...il.com" <scott.s.lowe@...il.com>
Subject: Re: [REGRESSION] Touchpad failure after e7348396c6d5 ("Input: ALPS -
 fix V8+ protocol handling (73 03 28)")

On Mon, Jun 19, 2017 at 01:02:18PM -0700, Laura Abbott wrote:
> On 06/19/2017 11:43 AM, Paul Donohue wrote:
> > I get the same results as you - x_max and y_max affect cursor speed, and x_res and y_res seem to have no effect.  I can't seem to come up with any values that cause intermittent cursor issues on one side of the touchpad.
> > Both max and res do get passed up to the X driver, and I do see references to both max and resolution in xf86-input-evdev, although I haven't actually traced it through to see if/where each value is actually consumed with my setup.
> > 
> > Maybe we should ask the user to try a few more tests?
> > 1) Using the original code (without the modifications from bug 195215), add the following before 'return 0' at the end of alps_update_device_area_ss4_v2(), then run `dmesg | grep num-electrodes` after loading the alps kernel module to get the output.  This should tell us what values the user is actually reading from the hardware:
> > psmouse_err(psmouse,
> >     "pitch %dx%d num-electrodes %dx%d physical size %dx%dmm res %dx%d max %dx%d\n",
> >     x_pitch, y_pitch, num_x_electrode, num_y_electrode,
> >     x_phys / 10, y_phys / 10, priv->x_res, priv->y_res, priv->x_max, priv->y_max);
> > 2) Use the old electrode count code but the new pitch code:
> > 	if (IS_SS4PLUS_DEV(priv->dev_id)) {
> > 		num_x_electrode =
> > 			SS4_NUMSENSOR_XOFFSET + (otp[1][0] & 0x0F);
> > 		num_y_electrode =
> > 			SS4_NUMSENSOR_YOFFSET + ((otp[1][0] >> 4) & 0x0F);
> > 
> > 		priv->x_max =
> > 			(num_x_electrode - 1) * SS4_COUNT_PER_ELECTRODE;
> > 		priv->y_max =
> > 			(num_y_electrode - 1) * SS4_COUNT_PER_ELECTRODE;
> > 
> > 		x_pitch = (otp[0][1] & 0x0F) + SS4PLUS_MIN_PITCH_MM;
> > 		y_pitch = ((otp[0][1] >> 4) & 0x0F) + SS4PLUS_MIN_PITCH_MM;
> > 
> > 	} else {
> > 3) Use the new electrode count code but the old pitch code:
> > 	if (IS_SS4PLUS_DEV(priv->dev_id)) {
> > 		num_x_electrode =
> > 			SS4PLUS_NUMSENSOR_XOFFSET + (otp[0][2] & 0x0F);
> > 		num_y_electrode =
> > 			SS4PLUS_NUMSENSOR_YOFFSET + ((otp[0][2] >> 4) & 0x0F);
> > 
> > 		priv->x_max =
> > 			(num_x_electrode - 1) * SS4PLUS_COUNT_PER_ELECTRODE;
> > 		priv->y_max =
> > 			(num_y_electrode - 1) * SS4PLUS_COUNT_PER_ELECTRODE;
> > 
> > 		x_pitch = ((otp[1][2] >> 2) & 0x07) + SS4_MIN_PITCH_MM;
> > 		y_pitch = ((otp[1][2] >> 5) & 0x07) + SS4_MIN_PITCH_MM;
> > 
> > 	} else {
> > 
> 
> Can you produce patches for these test cases?

I've reduced it to two test cases.  Patches attached.


View attachment "patch1" of type "text/plain" (1429 bytes)

View attachment "patch2" of type "text/plain" (1102 bytes)