[PATCH] [RFC] Revert "mmc: core: Fixup support for writeback-cache for eMMC and SD"

[Marek Vasut <marex@denx.de>]

This reverts commit 08ebf903af57cda6d773f3dd1671b64f73b432b8.

On STM32MP153C DHCOR DRC Compact with microSD card
Kingston Canvas Go! Plus MicroSDXC I 64 GiB U3/V30/A2 SDCG3/64GB
it is no longer possible to mount ext4 filesystem.

Git bisect points to this commit which is being reverted here. A bit of
investigation shows that for non-working microSD cards
  cache_enabled=TRUE fua_enabled=false
For working microSD card (Kingston Canvas React Plus, MicroSDXC II
64 GiB U3/V90/A1 SDCR2/64GB)
  cache_enabled=FALSE fua_enabled=false

It seems enabling the cache for SD cards causes the issue. Before the
reverted commit, the cache was not reported enabled for SD cards. I am
not sure whether such blunt revert is the correct solution however, any
ideas ?

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: "Christian Löhle" <CLoehle@hyperstone.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Avri Altman <avri.altman@wdc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marek Vasut <marex@denx.de>
Cc: Michael Wu <michael@allwinnertech.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Seunghui Lee <sh043.lee@samsung.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-mmc@vger.kernel.org
---
 drivers/mmc/core/block.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index db6d8a0999100..72aa47af11d37 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2413,8 +2413,6 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	struct mmc_blk_data *md;
 	int devidx, ret;
 	char cap_str[10];
-	bool cache_enabled = false;
-	bool fua_enabled = false;
 
 	devidx = ida_simple_get(&mmc_blk_ida, 0, max_devices, GFP_KERNEL);
 	if (devidx < 0) {
@@ -2494,17 +2492,13 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 			md->flags |= MMC_BLK_CMD23;
 	}
 
-	if (md->flags & MMC_BLK_CMD23 &&
+	if (mmc_card_mmc(card) &&
+	    md->flags & MMC_BLK_CMD23 &&
 	    ((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) ||
 	     card->ext_csd.rel_sectors)) {
 		md->flags |= MMC_BLK_REL_WR;
-		fua_enabled = true;
-		cache_enabled = true;
+		blk_queue_write_cache(md->queue.queue, true, true);
 	}
-	if (mmc_cache_enabled(card->host))
-		cache_enabled  = true;
-
-	blk_queue_write_cache(md->queue.queue, cache_enabled, fua_enabled);
 
 	string_get_size((u64)size, 512, STRING_UNITS_2,
 			cap_str, sizeof(cap_str));
-- 
2.39.2