title: SDHI; mmc_send_abort_tuning needs refactorization to support SD cards
team: IO
key: 2df07932-117d-11ec-bc26-4ffb07de7674
assignee: Wolfram
status: Active

bsp51x:
 - 2d7c017355ce83b26ef739183f28a8e0da5ea233 # mmc: core: mmc_ops: Enable stop command

upstream:

comments:
 - details at lore.kernel.org/all/20210831133349.18203-1-wsa+renesas@sang-engineering.com/
 - v1; https://lore.kernel.org/r/20210914182023.8103-1-wsa+renesas@sang-engineering.com
 - upstream review hinted that this might be only a workaround
 - one alternative found by Wolfram is to delay 100ms after the cmd error
 - for Wolfram's setup, the issue only happens with 4tap devices and a SanDisk card
 - another alternative seems to use the 1:4 divider instead of the 2:2
 - needs further investigation
 - BSP team reports that the 1:4 divider doesn't work for them
 - next step is discover why the 100ms delay works and if we can find a better condition to wait for
 - Wolfram got a reliably failing SD card from another user of Renesas hardware