The patch titled
mmc: avoid sdhci DMA boundaries
has been removed from the -mm tree. Its filename is
mmc-avoid-sdhci-dma-boundaries.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: mmc: avoid sdhci DMA boundaries
From: Pierre Ossman <drzeus@xxxxxxxxx>
The sdhci controllers will issue an interrupt when a configurable number of
bytes have been transfered using DMA. The purpose is to handle multiple,
scattered memory pages.
Unfortunately, it requires that all transfers are completely aligned to memory
pages, which we cannot guarantee. So we just disable the function.
Signed-off-by: Pierre Ossman <drzeus@xxxxxxxxx>
Cc: Russell King <rmk@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/mmc/sdhci.c | 13 +++++++++----
drivers/mmc/sdhci.h | 1 +
2 files changed, 10 insertions(+), 4 deletions(-)
diff -puN drivers/mmc/sdhci.c~mmc-avoid-sdhci-dma-boundaries drivers/mmc/sdhci.c
--- a/drivers/mmc/sdhci.c~mmc-avoid-sdhci-dma-boundaries
+++ a/drivers/mmc/sdhci.c
@@ -326,6 +326,9 @@ static void sdhci_prepare_data(struct sd
DBG("tsac %d ms nsac %d clk\n",
data->timeout_ns / 1000000, data->timeout_clks);
+ /* Sanity checks */
+ BUG_ON((1 << data->blksz_bits) * data->blocks > 524288);
+
/* timeout in us */
target_timeout = data->timeout_ns / 1000 +
data->timeout_clks / host->clock;
@@ -375,7 +378,9 @@ static void sdhci_prepare_data(struct sd
host->remain = host->cur_sg->length;
}
- writew(data->blksz, host->ioaddr + SDHCI_BLOCK_SIZE);
+ /* We do not handle DMA boundaries, so set it to max (512 KiB) */
+ writew(SDHCI_MAKE_BLKSZ(7, data->blksz),
+ host->ioaddr + SDHCI_BLOCK_SIZE);
writew(data->blocks, host->ioaddr + SDHCI_BLOCK_COUNT);
}
@@ -1188,10 +1193,10 @@ static int __devinit sdhci_probe_slot(st
mmc->max_phys_segs = 16;
/*
- * Maximum number of sectors in one transfer. Limited by sector
- * count register.
+ * Maximum number of sectors in one transfer. Limited by DMA boundary
+ * size (512KiB), which means (512 KiB/512=) 1024 entries.
*/
- mmc->max_sectors = 0x3FFF;
+ mmc->max_sectors = 1024;
/*
* Maximum segment size. Could be one segment with the maximum number
diff -puN drivers/mmc/sdhci.h~mmc-avoid-sdhci-dma-boundaries drivers/mmc/sdhci.h
--- a/drivers/mmc/sdhci.h~mmc-avoid-sdhci-dma-boundaries
+++ a/drivers/mmc/sdhci.h
@@ -23,6 +23,7 @@
#define SDHCI_DMA_ADDRESS 0x00
#define SDHCI_BLOCK_SIZE 0x04
+#define SDHCI_MAKE_BLKSZ(dma, blksz) (((dma & 0x7) << 12) | (blksz & 0xFFF))
#define SDHCI_BLOCK_COUNT 0x06
_
Patches currently in -mm which might be from drzeus@xxxxxxxxx are
origin.patch
-
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