Reopening per the maintainer's request in the closing message — this
reproduces exactly on the current bookworm-backports kernel.
Hardware: Samsung Galaxy Book 4 (DMI: SAMSUNG ELECTRONICS CO., LTD.
750XGK/NP750XGJ-KG5IT)
Reader: Realtek RTS5129 (usb 0bda:0129)
Kernel: 6.12.95+deb12-amd64 (bookworm-backports)
Same failure signature as the original report, continuous on every card
insertion:
mmc0: Card stuck being busy! __mmc_poll_for_busy
mmc0: error -110 whilst initialising SD card
Regarding the commit mentioned earlier in this thread
(4dad599b8b5d1ffc5ef12a2edb13d15d537202ba): I checked it, and it's a
runtime-PM/polling-efficiency change (avoid polling when no card is
present), not a fix for card initialization. It's already present in
6.12.95 and the failure still occurs, so that commit does not resolve this
bug.
This confirms the RTS5129 incompatibility in
rtsx_usb_sdmmc/rtsx_usb_ms/rtsx_usb (originally introduced in the
3.15->3.16 transition, see the 2015 LKML thread [1] and Ubuntu #1579748
[2]) is still present, and that OEMs are still shipping this exact
controller in new laptops as of 2023-2024 — so this will keep affecting new
hardware, not just legacy devices.
Workaround: reverting to the old staging-era driver still works with zero
source changes required against 6.12. Built and confirmed working via
https://github.com/aurorafossorg/rts5139 (DKMS-packaged, survives kernel
updates automatically). I've opened a PR there documenting this exact
configuration: https://github.com/ljmf00/rts5139/pull/3 (pending merge).
Blacklisting rtsx_usb_sdmmc/rtsx_usb_ms/rtsx_usb and loading that driver
instead restores full read/write access.
Given this is an eleven-year-old regression that appears to be a genuine
architectural gap (rtsx_usb_sdmmc is missing logic like rtsx_usb_get_rsp()
that exists in the old driver), I don't expect an upstream fix soon, but
wanted to leave this here for the next person who searches this error on
newer hardware.
[1] https://lkml.iu.edu/hypermail/linux/kernel/1501.0/02164.html
[2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1579748
