mmc: support BKOPS feature for eMMC
Enable eMMC background operations (BKOPS) feature.
If URGENT_BKOPS is set after a response, note that BKOPS are required.
Immediately run BKOPS if required. Read/write operations should be
requested during BKOPS(LEVEL-1), then issue HPI to interrupt the
ongoing BKOPS and service the foreground operation.
(This patch only controls the LEVEL2/3.)
When repeating the writing 1GB data, at a certain time, performance is
decreased. At that time, card triggers the Level-3 or Level-2. After
running bkops, performance is recovered.
Future considerations:
* Check BKOPS_LEVEL=1 and start BKOPS in a preventive manner.
* Interrupt ongoing BKOPS before powering off the card.
* How do we get BKOPS_STATUS value (periodically send ext_csd command)?
* If using periodic bkops, also consider runtime_pm control.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Reviewed-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 396b258..7509de1 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -463,6 +463,17 @@
}
if (card->ext_csd.rev >= 5) {
+ /* check whether the eMMC card supports BKOPS */
+ if (ext_csd[EXT_CSD_BKOPS_SUPPORT] & 0x1) {
+ card->ext_csd.bkops = 1;
+ card->ext_csd.bkops_en = ext_csd[EXT_CSD_BKOPS_EN];
+ card->ext_csd.raw_bkops_status =
+ ext_csd[EXT_CSD_BKOPS_STATUS];
+ if (!card->ext_csd.bkops_en)
+ pr_info("%s: BKOPS_EN bit is not set\n",
+ mmc_hostname(card->host));
+ }
+
/* check whether the eMMC card supports HPI */
if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x1) {
card->ext_csd.hpi = 1;