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mmc: at91_mci: avoid timeouts

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The at91 mci controller internal state machine seems to often crash. This can
be fixed by resetting the controller after each command for at91rm9200 and by
setting the MCI_BLKR register on at91sam926*.

Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Hans J Koch <hjk@linutronix.de>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This commit is contained in:
Marc Pignat 2008-05-30 14:07:47 +02:00 committed by Pierre Ossman
parent e181dce8ac
commit c5a89c6c08
2 changed files with 52 additions and 0 deletions
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48
drivers/mmc/host/at91_mci.c
View file

@ -130,6 +130,43 @@ struct at91mci_host
struct timer_list timer;
};
/*
* Reset the controller and restore most of the state
*/
static void at91_reset_host(struct at91mci_host *host)
{
unsigned long flags;
u32 mr;
u32 sdcr;
u32 dtor;
u32 imr;
local_irq_save(flags);
imr = at91_mci_read(host, AT91_MCI_IMR);
at91_mci_write(host, AT91_MCI_IDR, 0xffffffff);
/* save current state */
mr = at91_mci_read(host, AT91_MCI_MR) & 0x7fff;
sdcr = at91_mci_read(host, AT91_MCI_SDCR);
dtor = at91_mci_read(host, AT91_MCI_DTOR);
/* reset the controller */
at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIDIS | AT91_MCI_SWRST);
/* restore state */
at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIEN);
at91_mci_write(host, AT91_MCI_MR, mr);
at91_mci_write(host, AT91_MCI_SDCR, sdcr);
at91_mci_write(host, AT91_MCI_DTOR, dtor);
at91_mci_write(host, AT91_MCI_IER, imr);
/* make sure sdio interrupts will fire */
at91_mci_read(host, AT91_MCI_SR);
local_irq_restore(flags);
}
static void at91_timeout_timer(unsigned long data)
{
struct at91mci_host *host;
@ -148,6 +185,7 @@ static void at91_timeout_timer(unsigned long data)
host->request->cmd->error = -ETIMEDOUT;
}
at91_reset_host(host);
mmc_request_done(host->mmc, host->request);
}
}
@ -512,6 +550,11 @@ static void at91_mci_send_command(struct at91mci_host *host, struct mmc_command
mr |= AT91_MCI_PDCMODE;
at91_mci_write(host, AT91_MCI_MR, mr);
if (!cpu_is_at91rm9200())
at91_mci_write(host, AT91_MCI_BLKR,
AT91_MCI_BLKR_BCNT(blocks) |
AT91_MCI_BLKR_BLKLEN(block_length));
/*
* Disable the PDC controller
*/
@ -584,6 +627,11 @@ static void at91_mci_process_next(struct at91mci_host *host)
at91_mci_send_command(host, host->request->stop);
} else {
del_timer(&host->timer);
/* the at91rm9200 mci controller hangs after some transfers,
* and the workaround is to reset it after each transfer.
*/
if (cpu_is_at91rm9200())
at91_reset_host(host);
mmc_request_done(host->mmc, host->request);
}
}

4
include/asm-arm/arch-at91/at91_mci.h
View file

@ -75,6 +75,10 @@
#define AT91_MCI_TRTYP_MULTIPLE (1 << 19)
#define AT91_MCI_TRTYP_STREAM (2 << 19)
#define AT91_MCI_BLKR 0x18 /* Block Register */
#define AT91_MCI_BLKR_BCNT(n) ((0xffff & (n)) << 0) /* Block count */
#define AT91_MCI_BLKR_BLKLEN(n) ((0xffff & (n)) << 16) /* Block lenght */
#define AT91_MCI_RSPR(n) (0x20 + ((n) * 4)) /* Response Registers 0-3 */
#define AT91_MCR_RDR 0x30 /* Receive Data Register */
#define AT91_MCR_TDR 0x34 /* Transmit Data Register */