• Jaehoon Chung's avatar
    mmc: support BKOPS feature for eMMC · 950d56ac
    Jaehoon Chung authored
    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: default avatarJaehoon Chung <jh80.chung@samsung.com>
    Signed-off-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
    Signed-off-by: default avatarKonstantin Dorfman <kdorfman@codeaurora.org>
    Reviewed-by: default avatarMaya Erez <merez@codeaurora.org>
    Signed-off-by: default avatarChris Ball <cjb@laptop.org>
    950d56ac
mmc_ops.c 13.2 KB