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Subject[PATCH] mmc: at91_mci: fix hanging and rework to match flowcharts
Fixes hanging using multi block operations (seen during CMD25).
Follows closely the datasheet flowcharts.

This piece of code handles better big file writing. I had to take care
of the notbusy signal during write (at91_mci_handle_cmdrdy function) and
to rearrange the AT91_MCI_ENDRX and AT91_MCI_RXBUFF flag usage.

Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
---
This second patch is rebuild following Mariusz and Pierre comments.
This patch is applied on top of the "typo" one :
http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.22-rc6/2.6.22-rc6-mm1/broken-out/mmc-at91_mci-typo.patch

It is cooked with the help of Wu Xuan and Marc Pignat. Big thanks to them.

It has been tested on several systems and reported to work ok :
at91rm9200 ok w/ 1 wire
at91sam9261 ok w/ 1 wire
at91sam926[03] ok w/ 4 wires
The code takes care of those specificities.

drivers/mmc/host/at91_mci.c | 199 ++++++++++++++++++----------------
1 file changed, 108 insertions(+), 91 deletions(-)
Index: b/drivers/mmc/host/at91_mci.c
===================================================================
--- a/drivers/mmc/host/at91_mci.c
+++ b/drivers/mmc/host/at91_mci.c
@@ -80,8 +78,6 @@

#define DRIVER_NAME "at91_mci"

-#undef SUPPORT_4WIRE
-
#define FL_SENT_COMMAND (1 << 0)
#define FL_SENT_STOP (1 << 1)

@@ -270,8 +266,6 @@ static void at91_mci_post_dma_read(struc
}

while (host->in_use_index < host->transfer_index) {
- unsigned int *buffer;
-
struct scatterlist *sg;

pr_debug("finishing index %d\n", host->in_use_index);
@@ -282,20 +276,22 @@ static void at91_mci_post_dma_read(struc

dma_unmap_page(NULL, sg->dma_address, sg->length, DMA_FROM_DEVICE);

- /* Swap the contents of the buffer */
- buffer = kmap_atomic(sg->page, KM_BIO_SRC_IRQ) + sg->offset;
- pr_debug("buffer = %p, length = %d\n", buffer, sg->length);
-
data->bytes_xfered += sg->length;

if (cpu_is_at91rm9200()) { /* AT91RM9200 errata */
+ unsigned int *buffer;
int index;

+ /* Swap the contents of the buffer */
+ buffer = kmap_atomic(sg->page, KM_BIO_SRC_IRQ) + sg->offset;
+ pr_debug("buffer = %p, length = %d\n", buffer, sg->length);
+
for (index = 0; index < (sg->length / 4); index++)
buffer[index] = swab32(buffer[index]);
+
+ kunmap_atomic(buffer, KM_BIO_SRC_IRQ);
}

- kunmap_atomic(buffer, KM_BIO_SRC_IRQ);
flush_dcache_page(sg->page);
}

@@ -303,8 +299,8 @@ static void at91_mci_post_dma_read(struc
if (host->transfer_index < data->sg_len)
at91_mci_pre_dma_read(host);
else {
+ at91_mci_write(host, AT91_MCI_IDR, AT91_MCI_ENDRX);
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_RXBUFF);
- at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
}

pr_debug("post dma read done\n");
@@ -325,7 +321,6 @@ static void at91_mci_handle_transmitted(

/* Now wait for cmd ready */
at91_mci_write(host, AT91_MCI_IDR, AT91_MCI_TXBUFE);
- at91_mci_write(host, AT91_MCI_IER, AT91_MCI_NOTBUSY);

cmd = host->cmd;
if (!cmd) return;
@@ -333,18 +328,53 @@ static void at91_mci_handle_transmitted(
data = cmd->data;
if (!data) return;

+ if (cmd->data->flags & MMC_DATA_MULTI) {
+ pr_debug("multiple write : wait for BLKE...\n");
+ at91_mci_write(host, AT91_MCI_IER, AT91_MCI_BLKE);
+ } else
+ at91_mci_write(host, AT91_MCI_IER, AT91_MCI_NOTBUSY);
+
data->bytes_xfered = host->total_length;
}

+/*Handle after command sent ready*/
+static int at91_mci_handle_cmdrdy(struct at91mci_host *host)
+{
+ if (!host->cmd)
+ return 1;
+ else if (!host->cmd->data) {
+ if (host->flags & FL_SENT_STOP) {
+ /*After multi block write, we must wait for NOTBUSY*/
+ at91_mci_write(host, AT91_MCI_IER, AT91_MCI_NOTBUSY);
+ } else return 1;
+ } else if (host->cmd->data->flags & MMC_DATA_WRITE) {
+ /*After sendding multi-block-write command, start DMA transfer*/
+ at91_mci_write(host, AT91_MCI_IER, AT91_MCI_TXBUFE);
+ at91_mci_write(host, AT91_MCI_IER, AT91_MCI_BLKE);
+ at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
+ }
+
+ /* command not completed, have to wait */
+ return 0;
+}
+
+
/*
* Enable the controller
*/
static void at91_mci_enable(struct at91mci_host *host)
{
+ unsigned int mr;
+
at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIEN);
at91_mci_write(host, AT91_MCI_IDR, 0xffffffff);
at91_mci_write(host, AT91_MCI_DTOR, AT91_MCI_DTOMUL_1M | AT91_MCI_DTOCYC);
- at91_mci_write(host, AT91_MCI_MR, AT91_MCI_PDCMODE | 0x34a);
+ mr = AT91_MCI_PDCMODE | 0x34a;
+
+ if (cpu_is_at91sam9260() || cpu_is_at91sam9263())
+ mr |= AT91_MCI_RDPROOF | AT91_MCI_WRPROOF;
+
+ at91_mci_write(host, AT91_MCI_MR, mr);

/* use Slot A or B (only one at same time) */
at91_mci_write(host, AT91_MCI_SDCR, host->board->slot_b);
@@ -360,9 +390,8 @@ static void at91_mci_disable(struct at91

/*
* Send a command
- * return the interrupts to enable
*/
-static unsigned int at91_mci_send_command(struct at91mci_host *host, struct mmc_command *cmd)
+static void at91_mci_send_command(struct at91mci_host *host, struct mmc_command *cmd)
{
unsigned int cmdr, mr;
unsigned int block_length;
@@ -373,8 +402,7 @@ static unsigned int at91_mci_send_comman

host->cmd = cmd;

- /* Not sure if this is needed */
-#if 0
+ /* Needed for leaving busy state before CMD1 */
if ((at91_mci_read(host, AT91_MCI_SR) & AT91_MCI_RTOE) && (cmd->opcode == 1)) {
pr_debug("Clearing timeout\n");
at91_mci_write(host, AT91_MCI_ARGR, 0);
@@ -384,7 +412,7 @@ static unsigned int at91_mci_send_comman
pr_debug("Clearing: SR = %08X\n", at91_mci_read(host, AT91_MCI_SR));
}
}
-#endif
+
cmdr = cmd->opcode;

if (mmc_resp_type(cmd) == MMC_RSP_NONE)
@@ -441,50 +469,48 @@ static unsigned int at91_mci_send_comman
at91_mci_write(host, ATMEL_PDC_TCR, 0);
at91_mci_write(host, ATMEL_PDC_TNPR, 0);
at91_mci_write(host, ATMEL_PDC_TNCR, 0);
+ ier = AT91_MCI_CMDRDY;
+ } else {
+ /* zero block length and PDC mode */
+ mr = at91_mci_read(host, AT91_MCI_MR) & 0x7fff;
+ at91_mci_write(host, AT91_MCI_MR, mr | (block_length << 16) | AT91_MCI_PDCMODE);
+
+ /*
+ * Disable the PDC controller
+ */
+ at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);

- at91_mci_write(host, AT91_MCI_ARGR, cmd->arg);
- at91_mci_write(host, AT91_MCI_CMDR, cmdr);
- return AT91_MCI_CMDRDY;
- }
-
- mr = at91_mci_read(host, AT91_MCI_MR) & 0x7fff; /* zero block length and PDC mode */
- at91_mci_write(host, AT91_MCI_MR, mr | (block_length << 16) | AT91_MCI_PDCMODE);
+ if (cmdr & AT91_MCI_TRCMD_START) {
+ data->bytes_xfered = 0;
+ host->transfer_index = 0;
+ host->in_use_index = 0;
+ if (cmdr & AT91_MCI_TRDIR) {
+ /*
+ * Handle a read
+ */
+ host->buffer = NULL;
+ host->total_length = 0;

- /*
- * Disable the PDC controller
- */
- at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
-
- if (cmdr & AT91_MCI_TRCMD_START) {
- data->bytes_xfered = 0;
- host->transfer_index = 0;
- host->in_use_index = 0;
- if (cmdr & AT91_MCI_TRDIR) {
- /*
- * Handle a read
- */
- host->buffer = NULL;
- host->total_length = 0;
-
- at91_mci_pre_dma_read(host);
- ier = AT91_MCI_ENDRX /* | AT91_MCI_RXBUFF */;
- }
- else {
- /*
- * Handle a write
- */
- host->total_length = block_length * blocks;
- host->buffer = dma_alloc_coherent(NULL,
- host->total_length,
- &host->physical_address, GFP_KERNEL);
-
- at91_mci_sg_to_dma(host, data);
-
- pr_debug("Transmitting %d bytes\n", host->total_length);
-
- at91_mci_write(host, ATMEL_PDC_TPR, host->physical_address);
- at91_mci_write(host, ATMEL_PDC_TCR, host->total_length / 4);
- ier = AT91_MCI_TXBUFE;
+ at91_mci_pre_dma_read(host);
+ ier = AT91_MCI_ENDRX /* | AT91_MCI_RXBUFF */;
+ }
+ else {
+ /*
+ * Handle a write
+ */
+ host->total_length = block_length * blocks;
+ host->buffer = dma_alloc_coherent(NULL,
+ host->total_length,
+ &host->physical_address, GFP_KERNEL);
+
+ at91_mci_sg_to_dma(host, data);
+
+ pr_debug("Transmitting %d bytes\n", host->total_length);
+
+ at91_mci_write(host, ATMEL_PDC_TPR, host->physical_address);
+ at91_mci_write(host, ATMEL_PDC_TCR, host->total_length / 4);
+ ier = AT91_MCI_CMDRDY;
+ }
}
}

@@ -499,24 +525,9 @@ static unsigned int at91_mci_send_comman
if (cmdr & AT91_MCI_TRCMD_START) {
if (cmdr & AT91_MCI_TRDIR)
at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTEN);
- else
- at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
}
- return ier;
-}

-/*
- * Wait for a command to complete
- */
-static void at91_mci_process_command(struct at91mci_host *host, struct mmc_command *cmd)
-{
- unsigned int ier;
-
- ier = at91_mci_send_command(host, cmd);
-
- pr_debug("setting ier to %08X\n", ier);
-
- /* Stop on errors or the required value */
+ /* Enable selected interrupts */
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_ERRORS | ier);
}

@@ -527,11 +538,11 @@ static void at91_mci_process_next(struct
{
if (!(host->flags & FL_SENT_COMMAND)) {
host->flags |= FL_SENT_COMMAND;
- at91_mci_process_command(host, host->request->cmd);
+ at91_mci_send_command(host, host->request->cmd);
}
else if ((!(host->flags & FL_SENT_STOP)) && host->request->stop) {
host->flags |= FL_SENT_STOP;
- at91_mci_process_command(host, host->request->stop);
+ at91_mci_send_command(host, host->request->stop);
}
else
mmc_request_done(host->mmc, host->request);
@@ -698,29 +709,33 @@ static irqreturn_t at91_mci_irq(int irq,
at91_mci_handle_transmitted(host);
}

+ if (int_status & AT91_MCI_ENDRX) {
+ pr_debug("ENDRX\n");
+ at91_mci_post_dma_read(host);
+ }
+
if (int_status & AT91_MCI_RXBUFF) {
pr_debug("RX buffer full\n");
- at91_mci_write(host, AT91_MCI_IER, AT91_MCI_CMDRDY);
+ at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
+ at91_mci_write(host, AT91_MCI_IDR, AT91_MCI_RXBUFF | AT91_MCI_ENDRX);
+ completed = 1;
}

if (int_status & AT91_MCI_ENDTX)
pr_debug("Transmit has ended\n");

- if (int_status & AT91_MCI_ENDRX) {
- pr_debug("Receive has ended\n");
- at91_mci_post_dma_read(host);
- }
-
if (int_status & AT91_MCI_NOTBUSY) {
pr_debug("Card is ready\n");
- at91_mci_write(host, AT91_MCI_IER, AT91_MCI_CMDRDY);
+ completed = 1;
}

if (int_status & AT91_MCI_DTIP)
pr_debug("Data transfer in progress\n");

- if (int_status & AT91_MCI_BLKE)
+ if (int_status & AT91_MCI_BLKE) {
pr_debug("Block transfer has ended\n");
+ completed = 1;
+ }

if (int_status & AT91_MCI_TXRDY)
pr_debug("Ready to transmit\n");
@@ -730,7 +745,7 @@ static irqreturn_t at91_mci_irq(int irq,

if (int_status & AT91_MCI_CMDRDY) {
pr_debug("Command ready\n");
- completed = 1;
+ completed = at91_mci_handle_cmdrdy(host);
}
}

@@ -830,11 +845,11 @@ static int __init at91_mci_probe(struct
host->bus_mode = 0;
host->board = pdev->dev.platform_data;
if (host->board->wire4) {
-#ifdef SUPPORT_4WIRE
- mmc->caps |= MMC_CAP_4_BIT_DATA;
-#else
- printk("AT91 MMC: 4 wire bus mode not supported by this driver - using 1 wire\n");
-#endif
+ if (cpu_is_at91sam9260() || cpu_is_at91sam9263())
+ mmc->caps |= MMC_CAP_4_BIT_DATA;
+ else
+ printk("AT91 MMC: 4 wire bus mode not supported"
+ " - using 1 wire\n");
}

/*

-
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