Chris Clayton writes via Kernel.org Bugzilla: Following on from comment 15, I've patched and tested 5.4.44 (which Ubuntu's latest kernel seems to be based on) and the card reader works fine. Despite saying that I could take this no further, I did push on a little further and I've isolated the code that causes the rts5229 to no longer work since bede03a579b3 was applied. I've also reported the bug to LKML - see https://marc.info/?l=linux-kernel&m=159639774221968 Since reverting bede03a579b3 on recent kernels needs manual intervention, I've devised a simple patch (against linux-5.7.12). It applies correctly to 5.8.0 too but with offsets. If it doesn't apply properly on other kernels between 5.1-rc1 and 5.7.12, it is simple enough to apply manually. View: https://bugzilla.kernel.org/show_bug.cgi?id=204003#c16 You can reply to this message to join the discussion. -- Deet-doot-dot, I am a bot. Kernel.org Bugzilla (bugspray 0.1-dev)