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>
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 237f253..61b2c30 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -310,6 +310,11 @@
card->nr_parts++;
}
+static inline bool mmc_large_sector(struct mmc_card *card)
+{
+ return card->ext_csd.data_sector_size == 4096;
+}
+
/*
* The world is not perfect and supplies us with broken mmc/sdio devices.
* For at least some of these bugs we need a work-around.