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| author |   Jaehoon Chung <jh80.chung@samsung.com> | 2012-09-17 08:42:02 +0000 |
|---|---|---|
| committer |   Chris Ball <cjb@laptop.org> | 2012-10-03 10:05:12 -0400 |
| commit | 950d56acce5d401f477b91d0177605b543d63d07 (patch) | |
| tree | 205505f3976d02c6ef2fa9d6c911407f0e0f6c80 /drivers/mmc/core/mmc.c | |
| parent | mmc: sdhci: Test cd-gpio instead of SDHCI presence when probing (diff) | |
| download | linux-dev-950d56acce5d401f477b91d0177605b543d63d07.tar.xz linux-dev-950d56acce5d401f477b91d0177605b543d63d07.zip | |
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>
Diffstat (limited to 'drivers/mmc/core/mmc.c')
| -rw-r--r-- | drivers/mmc/core/mmc.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 396b25891bb9..7509de14aa78 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -463,6 +463,17 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd) } 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; |