I've tested plugging in an SD card to an older laptop (also on hirsute). That is OK.
I've also noticed that the: mmc0: error -84 whilst initialising SD card message appears at boot time if the mmc card slot is empty.
(the "mmc0: cannot verify signal voltage switch" message also appears on my old laptop, where things I working, so we can discount that).
I'll gather the debug info now.
I've tested plugging in an SD card to an older laptop (also on hirsute).
That is OK.
I've also noticed that the:
mmc0: error -84 whilst initialising SD card
message appears at boot time if the mmc card slot is empty.
(the "mmc0: cannot verify signal voltage switch" message also appears on my old laptop, where things I working, so we can discount that).
I'll gather the debug info now.