Isolated initially to renesas_sdhi_internal_dmac [1], Ulf suggested adding MMC_CAP_ERASE to the TMIO mmc core: On Fri, Nov 15, 2019 at 10:27:25AM +0100, Ulf Hansson wrote: -- snip -- This test and due to the discussions with Wolfram and you in this thread, I would actually suggest that you enable MMC_CAP_ERASE for all tmio variants, rather than just for this particular one. In other words, set the cap in tmio_mmc_host_probe() should be fine, as it seems none of the tmio variants supports HW busy detection at this point. -- snip -- Testing on R-Car H3ULCB-KF doesn't reveal any issues (v5.4-rc7): root@rcar-gen3:~# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT mmcblk0 179:0 0 59.2G 0 disk <--- eMMC mmcblk0boot0 179:8 0 4M 1 disk mmcblk0boot1 179:16 0 4M 1 disk mmcblk1 179:24 0 30G 0 disk <--- SD card root@rcar-gen3:~# time blkdiscard /dev/mmcblk0 real 0m8.659s user 0m0.001s sys 0m1.920s root@rcar-gen3:~# time blkdiscard /dev/mmcblk1 real 0m1.176s user 0m0.001s sys 0m0.124s [1] https://lore.kernel.org/linux-renesas-soc/20191112134808.23546-1-erosca@xxxxxxxxxxxxxx/ Cc: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Cc: Andrew Gabbasov <andrew_gabbasov@xxxxxxxxxx> Originally-by: Harish Jenny K N <harish_kandiga@xxxxxxxxxx> Suggested-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx> --- drivers/mmc/host/tmio_mmc_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c index 9b6e1001e77c..dec5a99f52cf 100644 --- a/drivers/mmc/host/tmio_mmc_core.c +++ b/drivers/mmc/host/tmio_mmc_core.c @@ -1184,7 +1184,7 @@ int tmio_mmc_host_probe(struct tmio_mmc_host *_host) if (ret == -EPROBE_DEFER) return ret; - mmc->caps |= MMC_CAP_4_BIT_DATA | pdata->capabilities; + mmc->caps |= MMC_CAP_ERASE | MMC_CAP_4_BIT_DATA | pdata->capabilities; mmc->caps2 |= pdata->capabilities2; mmc->max_segs = pdata->max_segs ? : 32; mmc->max_blk_size = TMIO_MAX_BLK_SIZE; -- 2.24.0
