These cards show abysmal write performance when
writes < 12K that are 8K unaligned cross an 8K barrier.
Signed-off-by: Andrei Warkentin <andreiw@xxxxxxxxxxxx>
---
drivers/mmc/card/Kconfig | 8 ++++++++
drivers/mmc/card/block-quirks.c | 22 ++++++++++++++++++++++
2 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/card/Kconfig b/drivers/mmc/card/Kconfig
index 063fa16..af2800e 100644
--- a/drivers/mmc/card/Kconfig
+++ b/drivers/mmc/card/Kconfig
@@ -21,6 +21,14 @@ config MMC_BLOCK_QUIRKS
help
Say Y here to enable various workarounds for known cards.
+config MMC_BLOCK_QUIRK_TOSHIBA_32NM
+ tristate "Toshiba MMC 32nm technology flash device quirks"
+ depends on MMC_BLOCK_QUIRKS
+ default n
+ help
+ Say Y if you have a Toshiba 32nm technology flash device,
+ such as MMC32G or MMC16G eMMCs.
+
config MMC_BLOCK_BOUNCE
bool "Use bounce buffer for simple hosts"
depends on MMC_BLOCK
diff --git a/drivers/mmc/card/block-quirks.c b/drivers/mmc/card/block-quirks.c
index e122a74..c142ffb 100644
--- a/drivers/mmc/card/block-quirks.c
+++ b/drivers/mmc/card/block-quirks.c
@@ -15,6 +15,23 @@
#include "queue.h"
#include "blk.h"
+#ifdef CONFIG_MMC_BLOCK_QUIRK_TOSHIBA_32NM
+static int toshiba_32nm_probe(struct mmc_blk_data *md, struct mmc_card *card)
+{
+ printk(KERN_INFO "Applying Toshiba 32nm workarounds\n");
+
+ /* Page size 8K, this card doesn't like unaligned writes
+ across 8K boundary. */
+ md->write_align_size = 8192;
+
+ /* Doing the alignment for accesses > 12K seems to
+ result in decreased perf. */
+ md->write_align_limit = 12288;
+ return 0;
+}
+#endif /* CONFIG_MMC_BLOCK_QUIRK_TOSHIBA_32NM */
+
+
/*
Caveat: Because this list is just looked up with a linear
search, take care that either overlapping revision ranges
@@ -22,6 +39,10 @@
a given revision has the desired effect.
*/
struct mmc_blk_quirk mmc_blk_quirks[] = {
+#ifdef CONFIG_MMC_BLOCK_QUIRK_TOSHIBA_32NM
+ MMC_BLK_QUIRK("MMC16G", 0x11, 0x0, toshiba_32nm_probe),
+ MMC_BLK_QUIRK("MMC32G", 0x11, 0x0100, toshiba_32nm_probe),
+#endif /* CONFIG_MMC_BLOCK_QUIRK_TOSHIBA_32NM */
};
static int mmc_blk_quirk_cmp(const struct mmc_blk_quirk *quirk,
@@ -49,3 +70,4 @@ struct mmc_blk_quirk *mmc_blk_quirk_find(struct mmc_card *card)
return NULL;
}
+
--
1.7.0.4
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