Re: [PATCH v7 0/4] drm/panic: Add a QR code panic screen

From: Jocelyn Falempe
Date: Fri Aug 23 2024 - 11:27:34 EST


On 22/08/2024 09:33, Jocelyn Falempe wrote:
This series adds a new panic screen, with the kmsg data embedded in a QR code.

The main advantage of QR code, is that you can copy/paste the debug data to a bug report.

The QR code encoder is written in rust, and is very specific to drm panic.
The reason is that it is called in a panic handler, and thus can't allocate memory, or use locking.
The rust code uses a few rust core API, and provides only two C entry points.
There is no particular reason to do it in rust, I just wanted to learn rust, and see if it can work in the kernel.

If you want to see what it looks like, I've put a few screenshots here:
https://github.com/kdj0c/panic_report/issues/1

I just pushed it to drm-misc-next

Thank you all for your reviews.

Best regards,

--

Jocelyn


v2:
* Rewrite the rust comments with Markdown (Alice Ryhl)
* Mark drm_panic_qr_generate() as unsafe (Alice Ryhl)
* Use CStr directly, and remove the call to as_str_unchecked()
(Alice Ryhl)
* Add a check for data_len <= data_size (Greg KH)

v3:
* Fix all rust comments (typo, punctuation) (Miguel Ojeda)
* Change the wording of safety comments (Alice Ryhl)
* Add a link to the javascript decoder in the Kconfig (Greg KH)
* Fix data_size and tmp_size check in drm_panic_qr_generate()

v4:
* Fix the logic to find next line and skip the '\n' (Alic Ryhl)
* Remove __LOG_PREFIX as it's not used (Alice Ryhl)

v5:
* Move drm_panic_[init|exit]() prototype to drm_crtc_internal.h
(Daniel Vetter)

v6:
* rebase, and handle conflict with 5d45c01dea6f ("drm/panic: Add panic description")
* Fix qr_width should be a signed int, to handle error code.

v7:
* rename r1/r2 to a/b in drm_rect_overlap() (Jani Nikula)

Jocelyn Falempe (4):
drm/panic: Add integer scaling to blit()
drm/rect: Add drm_rect_overlap()
drm/panic: Simplify logo handling
drm/panic: Add a QR code panic screen

drivers/gpu/drm/Kconfig | 31 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/drm_crtc_internal.h | 4 +
drivers/gpu/drm/drm_drv.c | 3 +
drivers/gpu/drm/drm_panic.c | 340 +++++++--
drivers/gpu/drm/drm_panic_qr.rs | 1003 +++++++++++++++++++++++++++
include/drm/drm_rect.h | 15 +
7 files changed, 1357 insertions(+), 40 deletions(-)
create mode 100644 drivers/gpu/drm/drm_panic_qr.rs


base-commit: 04b5b362bc2a36f1dfe5cad52c83b1ea9d25b87c