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authorSeungwon Jeon <tgih.jun@samsung.com>2013-02-06 17:02:46 +0900
committerChris Ball <cjb@laptop.org>2013-02-24 14:37:16 -0500
commitce39f9d17c14e56ea6772aa84393e6e0cc8499c4 (patch)
tree7b641a7f89614e3cc3f6ec2f81ee32f64ead4f0d /drivers/mmc/core
parentabd9ac144947d9a604beb763339e2f77ce8bec79 (diff)
downloadlinux-ce39f9d17c14e56ea6772aa84393e6e0cc8499c4.tar.bz2
mmc: support packed write command for eMMC4.5 devices
This patch supports packed write command of eMMC4.5 devices. Several writes can be grouped in packed command and all data of the individual commands can be sent in a single transfer on the bus. Large amounts of data in one transfer rather than several data of small size are effective for eMMC write internally. As a result, packed command help write throughput be improved. The following tables show the results of packed write. Type A: test none | packed iozone 25.8 | 31 tiotest 27.6 | 31.2 lmdd 31.2 | 35.4 Type B: test none | packed iozone 44.1 | 51.1 tiotest 47.9 | 52.5 lmdd 51.6 | 59.2 Type C: test none | packed iozone 19.5 | 32 tiotest 19.9 | 34.5 lmdd 22.8 | 40.7 Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com> Reviewed-by: Maya Erez <merez@codeaurora.org> Reviewed-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/core')
-rw-r--r--drivers/mmc/core/mmc_ops.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 6d8f7012d73a..49f04bc9d0eb 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -363,6 +363,7 @@ int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd)
return mmc_send_cxd_data(card, card->host, MMC_SEND_EXT_CSD,
ext_csd, 512);
}
+EXPORT_SYMBOL_GPL(mmc_send_ext_csd);
int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp)
{