[PATCH v2 2/2] mmc: block: Update ext_csd.cache_ctrl if it was written

From: Avri Altman
Date: Sun Apr 18 2021 - 02:00:40 EST


The cache function can be turned ON and OFF by writing to the CACHE_CTRL
byte (EXT_CSD byte [33]). However, card->ext_csd.cache_ctrl is only
set on init if cache size > 0.

Fix that by explicitly setting ext_csd.cache_ctrl on ext-csd write.

Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
---
drivers/mmc/core/block.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 6800feb70c92..0372702231ce 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -572,6 +572,18 @@ static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md,
main_md->part_curr = value & EXT_CSD_PART_CONFIG_ACC_MASK;
}

+ /*
+ * Make sure to update CACHE_CTRL in case it was changed. The cache
+ * will get turned back on if the card is re-initialized, e.g.
+ * suspend/resume or hw reset in recovery.
+ */
+ if ((MMC_EXTRACT_INDEX_FROM_ARG(cmd.arg) == EXT_CSD_CACHE_CTRL) &&
+ (cmd.opcode == MMC_SWITCH)) {
+ u8 value = MMC_EXTRACT_VALUE_FROM_ARG(cmd.arg) & 1;
+
+ card->ext_csd.cache_ctrl = value;
+ }
+
/*
* According to the SD specs, some commands require a delay after
* issuing the command.
--
2.25.1