Re: [cros-discuss] Re: Acer CB Spin 513: Touchpad jumpy and unusable after OS update

[Mr Anderson]

I did attempt to do this with a 103 image, but the recovery screen rejected it as outdated.  Same out-of-date error for versions 107-110 from the provided link.

The first version that was accepted was 111.  After rebooting it showed the same grey screen saying 'Your system is applying a critical update'.  I didn't see any errors and the machine rebooted to the welcome screen.

From guest mode I can see:

1) ChromeOS version 111.0.5563.118

2) Diagnostics correctly shows the CPU as 'Qualcomm 7180' instead of the odd 01a9 value on ChromeOS 115.

Unfortunately, the touchpad issue still persists, so I think the critical system update might have introduced the problem.  However, I can't verify this because I can't get back to a ChromeOS version prior to the critical system update.

On Wed, Aug 2, 2023 at 12:01 PM Nom De Plume <david....@gmail.com> wrote:

You can relatively easily go back a few versions by creating a recovery image from https://chromiumdash.appspot.com/serving-builds?deviceCategory=Chrome%20OS On the right side of the page for your device there are downloads for earlier versions

You would need to get the recovery creation extension from the webstore and use the local downloaded image

On Wed, Aug 2, 2023 at 1:51 PM Mr Anderson <acer...@gmail.com> wrote:

Is there any way for me to return this Chromebook back to ChromeOS 103 so I can see if the touchpad is or is not functional at that version?

What about the system firmware update that was applied?  I presume that was written somewhere other than the internal eMMC (e.g. CrOS EC, trackpad/keyboard firmware, Qualcomm SoC)?

It is possible I bought a defective unit with a malfunctioning touchpad, that is why I really want to test it out again on ChromeOS 103 where I am pretty sure it was working correctly.  The highly unreliable behavior of the touchpad is very noticeable so I am pretty confident I would have immediately noticed it on ChromeOS 103, even in the limited 10-15 minutes of use I had before rebooting to apply the ChromeOS update.  I recall it working correctly even on the ChromeOS 105 update, which was the first to apply.  After that, when it went 105 -> 115 (with the system firmware update), the touchpad became essentially unusable.

On Tue, Aug 1, 2023 at 1:56 PM Mr Anderson <acer...@gmail.com> wrote:

Hi All,

I just recently purchased an Acer Chromebook Spin 513 (lazor) used.  Upon first booting the device the ChromeOS version was at 103.  I decided to update it to the newest version possible.  It first updated to 105 and then to 115 after that.  However, after the 105 -> 115 update the touchpad is borderline unusable causing the cursor to frequently jump and/or just move unreliably despite a consistent finger velocity.

I have already submitted feedback for ChromeOS 115 and 117 (dev channel) where the problem exists.  I am hoping to narrow the problem down further to determine if the unit is defective or if the system updates introduced a problem.

Observations:

1) In the 10-15 minutes spent at ChromeOS 103, before updating, the touchpad worked as expected.  Not jumpy or unreliable, so I am pretty sure I didn't buy a unit with a defective touchpad.

2) Going from ChromeOS 105 -> 115 showed a grey screen at reboot indicating an 'important system firmware update' was being applied.  It looked like it succeeded as there was no clear indication of a failure/error message and the machine booted normally afterwards.

3) The About ChromeOS > Diagnostics screen correctly showed a 'Qualcomm sc7180' CPU before updating, now it oddly shows 'Qualcomm 01a9'.

In particular, (3) makes me think the firmware update didn't go as intended despite the machine working fine otherwise.  I have no idea how to check this further.  I also wonder if forcing the firmware update to apply again might clear up the issue, but I have no idea how to do so, if it is even possible?

Any help or guidance on what I can look at next is much appreciated!

Thanks,

Anderson

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[Mr Anderson]

Everything is up to date.  The hardware reset didn't do anything.  The touchpad is still unusable.

I can see that lazor has Closed Case Debugging (CCD) capabilities.  If I were to open the device and disable write-protect would it be possible to flash the device back to ChromeOS 103?

Again, I am pretty certain that the touchpad was working fine on ChromeOS 103, but I can't verify this now because the machine won't let me use any recovery image prior to 111.  Is there a check I can disable in dev mode and/or GBB flags that will allow me to temporarily revert back to ChromeOS 103?

On Wed, Aug 2, 2023 at 1:01 PM Dusk k <tejaksh...@gmail.com> wrote:

Hi there,

Based on your observations, it seems that the critical system update might have introduced the touchpad issue. Since you were unable to revert back to a ChromeOS version prior to the update, I recommend trying a few additional troubleshooting steps.

First, make sure that all of your Chromebook's drivers and firmware are up to date. You can do this by going to Settings > About Chrome OS > Check for updates.

If that doesn't resolve the issue, you can try performing a hardware reset on your Chromebook. To do this, power off your device and then press and hold the Refresh + Power buttons simultaneously for about 10-15 seconds. Release the buttons, then power on your Chromebook and see if the touchpad behavior improves.

If none of these steps work, it may be worth reaching out to the Chromebook manufacturer or a professional computer technician for further assistance. They may be able to provide more specific guidance or diagnose any potential hardware issues.

I hope this helps, and please let me know if you have any further questions.

[dragon788]

Is the touchpad only unusable while charging, or if you move to a different location like the couch or a table and aren't plugged into a charger, does it behave better?

[Mr Anderson]

The touchpad behaves the same way whether plugged in or not.

[Mr Anderson]

Yea, I have already put the device in developer mode (without opening it).  Specifically, I did so to enable USB boot so I could try a Debian Linux image.  The touchpad behaves the same way under Debian, but I am not sure this test ruled anything out because I think the CrOS EC and/or Qualcomm firmware play some role in the touchpad inputs.  If someone with more knowledge on this point could weigh in that would be great.

I just ordered a replacement touchpad, so hopefully by next week it should be clear whether or not the touchpad is the culprit.

On Wed, Aug 2, 2023 at 2:17 PM Nom De Plume <david....@gmail.com> wrote:

Your device is new enough that you can put it into developer mode without opening it up.  
To put your Chromebook into developer mode, you need to power it on while holding two additional keys. Hold Esc + Refresh, and then hit the Power button. Let go of the Escape and Refresh keys once it powers on. As soon as the "ChromeOS is missing or damaged" screen shows up, press Ctrl + D

[dragon788]

If you are in developer mode, access the crosh shell via Ctrl+Alt+t then type shell and enter and then `sudo evtest` and select the number for your trackpad and see if light and heavy events respond the way you'd expect.

There are config files in /etc/gesture/ and /opt/google/touch that have firmware and scripts but I'm not sure if those are used for touchpads or just touch screens.

I did stumble across this while trying to figure out how to query the /etc/udev/hwdb.bin that is the compiled version of what would normally exist in /etc/udev/hwdb.d and various /var and /usr places.

https://chromium.googlesource.com/chromiumos/docs/+/HEAD/input_stack.md#and-the-gestures-library

And this is the HORRIBLE UGLY GROSS hack I came up with to look at a little bit of what is in the hwdb.bin. It may not work on your system and it might eat your cat, YMMV.

# This is the board name NOT the model name, because drivers are generic for the BOARD not specific models in most cases.

export CBNAME=$(env | grep CHROMEOS_RELEASE_BOARD | sed -rn 's/.*=([[:alpha:]]+)-.*/\1/p')

# This fun hack splits the binary file on nulls and replaces them with newlines and then searches for the $CBNAME and looks around a couple lines to give a bit of context if there are specific rules for your board.

sed 's%\x00%\n%g' /etc/udev/hwdb.bin | grep -C 10 -i $CBNAME

# You can use this same search with the name of your touchpad to see if there are any specific rules for it in this file. Once upon a time you could examine or pull out the /etc/udev/hwdb.d files to use with Linux on the same hardware without reinventing the wheel, but they have hardened/minified the system more and that doesn't work anymore.

[Mr Anderson]

Thanks Torsha for alerting me to that flag, it will no doubt prove useful in troubleshooting these kinds of issues going forward!

The new touchpad arrived over the weekend.  After installing it everything appears to be normal at ChromeOS 115.0.5790.160.  Just to be sure I used recovery to put the machine back to ChromeOS 111.0.5563.118, upon reboot the device immediately showed the 'Your system is applying a critical update' message.  Afterwards the touchpad remained functional as expected.  Finally, I went into "About ChromeOS" and updated the device back to the latest version of ChromeOS (115.0.5790.160), it again showed the critical update screen.  After the update the touchpad is still working as expected.

So, it appears conclusive at this point that I bought a unit with a bad touchpad.  The seller was not upfront about this, so I will be in contact with them.  Such is the risk of buying used devices, but at least it was a quick and inexpensive fix.

Thank you everyone for your responses and guidance.  By far the most positive aspect of this experience was interacting with the ChromeOS community!  It helped me learn a few new things about troubleshooting issues in ChromeOS, so thanks!

-Anderson

On Thu, Aug 3, 2023 at 8:57 AM Torsha Banerjee <tor...@google.com> wrote:

if you are still able to reproduce the issue, we would need the the logs with  “Enable input event logging” flag at os://flags enabled. Do share the logs after you have enabled the flag.