[xu4] [4.14.180-176] mmc0 dmesg spam with bus speed messages #401
Description
Against a Odroid XU4q running 4.14.180-176 tag (current HEAD of odroidxu4-4.14.y) -
Dmesg is spammed with 4 messages, once a second. Definitely not OK.
[ 3069.842645] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 400000Hz, actual 396825HZ div = 63)
[ 3069.898673] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 300000Hz, actual 297619HZ div = 84)
[ 3069.954564] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 200000Hz, actual 200000HZ div = 125)
[ 3070.010645] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 100000Hz, actual 100000HZ div = 250)
[ 3070.490613] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 400000Hz, actual 396825HZ div = 63)
[ 3070.550598] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 300000Hz, actual 297619HZ div = 84)
[ 3070.606600] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 200000Hz, actual 200000HZ div = 125)
[ 3070.662552] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 100000Hz, actual 100000HZ div = 250)
It looks like it's checking for all of the possible bus speeds on the mmc once a second, possibly to detect if it has been hotplugged / connected (it's not). However, this log message shouldn't be spammed so much.
I will put a small patch against my own copy of Linux which removes the message, but this needs a more permanent fix.