Good Afternoon, I have been fighting a bug with sdhci on the tegra-30 based ouya since 5.6-rc1. I've traced it to the following commit: mmc: core: Specify timeouts for BKOPS and CACHE_FLUSH for eMMC 24ed3bd01d6a844fd5e8a75f48d0a3d10ed71bf9 [ 51.401369] mmc0: Card stuck being busy! mmc_poll_for_busy [ 51.407288] mmc0: cache flush error -110 [ 51.412347] blk_update_request: I/O error, dev mmcblk0, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0 It also caused issues with hitching with the bcm4330 sdio wifi chip. Reverting this commit fixes the issue. After reverting this commit, with the following commit still intact: mmc: core: Default to generic_cmd6_time as timeout in __mmc_switch() I am seeing a lot of the following messages: [ 22.626377] mmc0: unspecified timeout for CMD6 - use generic [ 22.687349] mmc0: unspecified timeout for CMD6 - use generic [ 23.362736] mmc0: unspecified timeout for CMD6 - use generic [ 23.487824] mmc0: unspecified timeout for CMD6 - use generic [ 23.547674] mmc0: unspecified timeout for CMD6 - use generic [ 23.745527] mmc0: unspecified timeout for CMD6 - use generic [ 23.817678] mmc0: unspecified timeout for CMD6 - use generic [ 24.045600] mmc0: unspecified timeout for CMD6 - use generic [ 24.155577] mmc0: unspecified timeout for CMD6 - use generic [ 24.223448] mmc0: unspecified timeout for CMD6 - use generic [ 24.286257] mmc0: unspecified timeout for CMD6 - use generic Very Respectfully, Peter Geis