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[MMC] Fix sdhci PIO routines
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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>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Pierre Ossman authored and Russell King committed Jul 2, 2006
1 parent 3192a28 commit a406f5a
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Showing 2 changed files with 101 additions and 63 deletions.
158 changes: 98 additions & 60 deletions drivers/mmc/sdhci.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -128,7 +122,7 @@ static void sdhci_init(struct sdhci_host *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);
Expand Down Expand Up @@ -189,88 +183,132 @@ static inline int sdhci_next_sg(struct sdhci_host* host)
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 = host->data->blksz;
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 = host->data->blksz;
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);
}
}

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)
Expand Down Expand Up @@ -863,7 +901,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
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)
Expand Down
6 changes: 3 additions & 3 deletions drivers/mmc/sdhci.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -95,8 +95,8 @@
#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
Expand All @@ -116,7 +116,7 @@
#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)

Expand Down

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