Test sample

[kdj0c]

This is a test sample to show what kind of data can be put in a drm_panic qr code, and decoded with this web project.

[kdj0c]

A new test sample with V40 QR code

[kdj0c]

Test sample with uncompressed kmsg.

[qwertychouskie]

Test sample with uncompressed kmsg.

This one I can't scan with my phone.

[kdj0c]

This one I can't scan with my phone.

Sometime it also depends on the app you're using. The first app I used on my Android phone was only able to scan the first screenshot (with ascii Tux), bigger QR-code never worked. I'm now using the app from gamma play, and it scan all three.

[qwertychouskie]

Some quick testing with the 2 troublesome QR codes:

• Barcode Scanner: Did not work, occasionally "scanned" a few numbers as a "UPC code"
• Barcode Scanner (different app, same name): Also did not work, also occasionally "scanned" a few numbers as a "UPC code"
• Binary Eye: Worked pretty much instantly

Might be worth investigating what's different between these, maybe there's some sort of subtle bug in the QR code that makes it not work on all apps, or maybe some of these apps have some sort of bug with large codes.

[OptikITLik]

How do you upload data if there is no internet connection?

[tq-steina]

I can't scan the last one (Test sample with uncompressed kmsg) with my Android phone

[NikitaBeloglazov]

Test sample with uncompressed kmsg scans normally with Samsung Camera

[lucmann]

I can't scan the last one (Test sample with uncompressed kmsg) with my Android phone

I can also scan that normally with my Android phone (Redmi Note 11T Pro), using WeChat app.

[microhobby]

This remember me of this: https://www.youtube.com/watch?v=KriAX7FxhZw

[Andy3153]

Test sample with uncompressed kmsg.

It scans normally for me. I'm on LineageOS and I'm using the default camera app.

[g0t4]

@kdj0c what are you using to generate the QR codes above?

I've got panic screen working. And I've compiled the kernel with DRM_PANIC_SCREEN_QR_CODE=y and booted it, but I still get the panic screen w/o QR codes. Is resolution a factor? IIAC the QR codes require a rather high resolution display to fit?

[kdj0c]

@g0t4 You also need to set DRM_PANIC_SCREEN=qr_code (or at runtime, as root:)
echo -n "qr_code" > /sys/module/drm/parameters/panic_screen

[g0t4]

@kdj0c you just made my day (actually my weekend)! THANK YOU

[g0t4]

here's a blue version, triggered via DRM_PANIC_DEBUG