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Subject[PATCH 09/21] [MMC] Fix sdhci PIO routines
Date
The sdhci controllers operate with blocks, not bytes. The PIO routines must
therefore make sure that the minimum unit transfered is a complete block.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
---
drivers/mmc/sdhci.c | 158 ++++++++++++++++++++++++++++++++-------------------
drivers/mmc/sdhci.h | 6 +-
2 files changed, 101 insertions(+), 63 deletions(-)
diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index b7a9ac2..eb6aee4 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -8,12 +8,6 @@
* published by the Free Software Foundation.
*/

- /*
- * Note that PIO transfer is rather crappy atm. The buffer full/empty
- * interrupts aren't reliable so we currently transfer the entire buffer
- * directly. Patches to solve the problem are welcome.
- */
-
#include <linux/delay.h>
#include <linux/highmem.h>
#include <linux/pci.h>
@@ -128,7 +122,7 @@ static void sdhci_init(struct sdhci_host
SDHCI_INT_DATA_CRC | SDHCI_INT_DATA_TIMEOUT | SDHCI_INT_INDEX |
SDHCI_INT_END_BIT | SDHCI_INT_CRC | SDHCI_INT_TIMEOUT |
SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT |
- SDHCI_INT_BUF_EMPTY | SDHCI_INT_BUF_FULL |
+ SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL |
SDHCI_INT_DMA_END | SDHCI_INT_DATA_END | SDHCI_INT_RESPONSE;

writel(intmask, host->ioaddr + SDHCI_INT_ENABLE);
@@ -189,79 +183,96 @@ static inline int sdhci_next_sg(struct s
return host->num_sg;
}

-static void sdhci_transfer_pio(struct sdhci_host *host)
+static void sdhci_read_block_pio(struct sdhci_host *host)
{
+ int blksize, chunk_remain;
+ u32 data;
char *buffer;
- u32 mask;
- int bytes, size;
- unsigned long max_jiffies;
+ int size;

- BUG_ON(!host->data);
+ DBG("PIO reading\n");

- if (host->num_sg == 0)
- return;
-
- bytes = 0;
- if (host->data->flags & MMC_DATA_READ)
- mask = SDHCI_DATA_AVAILABLE;
- else
- mask = SDHCI_SPACE_AVAILABLE;
+ blksize = 1 << host->data->blksz_bits;
+ chunk_remain = 0;
+ data = 0;

buffer = sdhci_kmap_sg(host) + host->offset;

- /* Transfer shouldn't take more than 5 s */
- max_jiffies = jiffies + HZ * 5;
+ while (blksize) {
+ if (chunk_remain == 0) {
+ data = readl(host->ioaddr + SDHCI_BUFFER);
+ chunk_remain = min(blksize, 4);
+ }

- while (host->size > 0) {
- if (time_after(jiffies, max_jiffies)) {
- printk(KERN_ERR "%s: PIO transfer stalled. "
- "Please report this to "
- BUGMAIL ".\n", mmc_hostname(host->mmc));
- sdhci_dumpregs(host);
+ size = min(host->size, host->remain);
+ size = min(size, chunk_remain);

- sdhci_kunmap_sg(host);
+ chunk_remain -= size;
+ blksize -= size;
+ host->offset += size;
+ host->remain -= size;
+ host->size -= size;
+ while (size) {
+ *buffer = data & 0xFF;
+ buffer++;
+ data >>= 8;
+ size--;
+ }

- host->data->error = MMC_ERR_FAILED;
- sdhci_finish_data(host);
- return;
+ if (host->remain == 0) {
+ sdhci_kunmap_sg(host);
+ if (sdhci_next_sg(host) == 0) {
+ BUG_ON(blksize != 0);
+ return;
+ }
+ buffer = sdhci_kmap_sg(host);
}
+ }

- if (!(readl(host->ioaddr + SDHCI_PRESENT_STATE) & mask))
- continue;
+ sdhci_kunmap_sg(host);
+}

- size = min(host->size, host->remain);
+static void sdhci_write_block_pio(struct sdhci_host *host)
+{
+ int blksize, chunk_remain;
+ u32 data;
+ char *buffer;
+ int bytes, size;

- if (size >= 4) {
- if (host->data->flags & MMC_DATA_READ)
- *(u32*)buffer = readl(host->ioaddr + SDHCI_BUFFER);
- else
- writel(*(u32*)buffer, host->ioaddr + SDHCI_BUFFER);
- size = 4;
- } else if (size >= 2) {
- if (host->data->flags & MMC_DATA_READ)
- *(u16*)buffer = readw(host->ioaddr + SDHCI_BUFFER);
- else
- writew(*(u16*)buffer, host->ioaddr + SDHCI_BUFFER);
- size = 2;
- } else {
- if (host->data->flags & MMC_DATA_READ)
- *(u8*)buffer = readb(host->ioaddr + SDHCI_BUFFER);
- else
- writeb(*(u8*)buffer, host->ioaddr + SDHCI_BUFFER);
- size = 1;
- }
+ DBG("PIO writing\n");
+
+ blksize = 1 << host->data->blksz_bits;
+ chunk_remain = 4;
+ data = 0;
+
+ bytes = 0;
+ buffer = sdhci_kmap_sg(host) + host->offset;
+
+ while (blksize) {
+ size = min(host->size, host->remain);
+ size = min(size, chunk_remain);

- buffer += size;
+ chunk_remain -= size;
+ blksize -= size;
host->offset += size;
host->remain -= size;
-
- bytes += size;
host->size -= size;
+ while (size) {
+ data >>= 8;
+ data |= (u32)*buffer << 24;
+ buffer++;
+ size--;
+ }
+
+ if (chunk_remain == 0) {
+ writel(data, host->ioaddr + SDHCI_BUFFER);
+ chunk_remain = min(blksize, 4);
+ }

if (host->remain == 0) {
sdhci_kunmap_sg(host);
if (sdhci_next_sg(host) == 0) {
- DBG("PIO transfer: %d bytes\n", bytes);
+ BUG_ON(blksize != 0);
return;
}
buffer = sdhci_kmap_sg(host);
@@ -269,8 +280,35 @@ static void sdhci_transfer_pio(struct sd
}

sdhci_kunmap_sg(host);
+}
+
+static void sdhci_transfer_pio(struct sdhci_host *host)
+{
+ u32 mask;
+
+ BUG_ON(!host->data);
+
+ if (host->size == 0)
+ return;
+
+ if (host->data->flags & MMC_DATA_READ)
+ mask = SDHCI_DATA_AVAILABLE;
+ else
+ mask = SDHCI_SPACE_AVAILABLE;
+
+ while (readl(host->ioaddr + SDHCI_PRESENT_STATE) & mask) {
+ if (host->data->flags & MMC_DATA_READ)
+ sdhci_read_block_pio(host);
+ else
+ sdhci_write_block_pio(host);
+
+ if (host->size == 0)
+ break;
+
+ BUG_ON(host->num_sg == 0);
+ }

- DBG("PIO transfer: %d bytes\n", bytes);
+ DBG("PIO transfer complete.\n");
}

static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
@@ -863,7 +901,7 @@ static void sdhci_data_irq(struct sdhci_
if (host->data->error != MMC_ERR_NONE)
sdhci_finish_data(host);
else {
- if (intmask & (SDHCI_INT_BUF_FULL | SDHCI_INT_BUF_EMPTY))
+ if (intmask & (SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL))
sdhci_transfer_pio(host);

if (intmask & SDHCI_INT_DATA_END)
diff --git a/drivers/mmc/sdhci.h b/drivers/mmc/sdhci.h
index a8f4521..f8df28f 100644
--- a/drivers/mmc/sdhci.h
+++ b/drivers/mmc/sdhci.h
@@ -95,8 +95,8 @@ #define SDHCI_SIGNAL_ENABLE 0x38
#define SDHCI_INT_RESPONSE 0x00000001
#define SDHCI_INT_DATA_END 0x00000002
#define SDHCI_INT_DMA_END 0x00000008
-#define SDHCI_INT_BUF_EMPTY 0x00000010
-#define SDHCI_INT_BUF_FULL 0x00000020
+#define SDHCI_INT_SPACE_AVAIL 0x00000010
+#define SDHCI_INT_DATA_AVAIL 0x00000020
#define SDHCI_INT_CARD_INSERT 0x00000040
#define SDHCI_INT_CARD_REMOVE 0x00000080
#define SDHCI_INT_CARD_INT 0x00000100
@@ -116,7 +116,7 @@ #define SDHCI_INT_ERROR_MASK 0xFFFF8000
#define SDHCI_INT_CMD_MASK (SDHCI_INT_RESPONSE | SDHCI_INT_TIMEOUT | \
SDHCI_INT_CRC | SDHCI_INT_END_BIT | SDHCI_INT_INDEX)
#define SDHCI_INT_DATA_MASK (SDHCI_INT_DATA_END | SDHCI_INT_DMA_END | \
- SDHCI_INT_BUF_EMPTY | SDHCI_INT_BUF_FULL | \
+ SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL | \
SDHCI_INT_DATA_TIMEOUT | SDHCI_INT_DATA_CRC | \
SDHCI_INT_DATA_END_BIT)

-
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