[PATCH v2] mmc: tmio: Add MMC_CAP_ERASE to allow erase/discard/trim requests

From: Eugeniu Rosca
Date: Fri Nov 15 2019 - 08:45:16 EST


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