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>
This commit is contained in:
Jaehoon Chung 2012-09-17 08:42:02 +00:00 committed by Chris Ball
parent bec9d4e593
commit 950d56acce
6 changed files with 220 additions and 8 deletions

View file

@ -134,6 +134,8 @@ struct mmc_host;
struct mmc_card;
struct mmc_async_req;
extern int mmc_stop_bkops(struct mmc_card *);
extern int mmc_read_bkops_status(struct mmc_card *);
extern struct mmc_async_req *mmc_start_req(struct mmc_host *,
struct mmc_async_req *, int *);
extern int mmc_interrupt_hpi(struct mmc_card *);
@ -142,6 +144,8 @@ extern int mmc_wait_for_cmd(struct mmc_host *, struct mmc_command *, int);
extern int mmc_app_cmd(struct mmc_host *, struct mmc_card *);
extern int mmc_wait_for_app_cmd(struct mmc_host *, struct mmc_card *,
struct mmc_command *, int);
extern void mmc_start_bkops(struct mmc_card *card, bool from_exception);
extern int __mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int, bool);
extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int);
#define MMC_ERASE_ARG 0x00000000