[U-Boot] [Patch] fsl_esdhc: Fix DMA transfer completion waiting loop

Dirk Behme
2013-06-10T12:06:12Z

On 08.04.2013 11:06, Andrew Gabbasov wrote:
> Rework the waiting for transfer completion loop condition
> to continue waiting until both Transfer Complete and DMA End
> interrupts occur. Checking of DLA bit in Present State register
> looks not needed in addition to interrupts status checking,
> so it can be removed from the condition. Also, DMA Error
> condition is added to the list of data errors, checked in the loop.
>
> Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
> ---
> drivers/mmc/fsl_esdhc.c | 3 +--
> include/fsl_esdhc.h | 4 +++-
> 2 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
> index 54b5363..814bba4 100644
> --- a/drivers/mmc/fsl_esdhc.c
> +++ b/drivers/mmc/fsl_esdhc.c
> @@ -400,8 +400,7 @@ esdhc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
>
> if (irqstat & DATA_ERR)
> return COMM_ERR;
> - } while (!(irqstat & IRQSTAT_TC) &&
> - (esdhc_read32(&regs->prsstat) & PRSSTAT_DLA));
> + } while ((irqstat & DATA_COMPLETE) != DATA_COMPLETE);
> #endif
> }
>
> diff --git a/include/fsl_esdhc.h b/include/fsl_esdhc.h
> index 47d2fe4..ea0880b 100644
> --- a/include/fsl_esdhc.h
> +++ b/include/fsl_esdhc.h
> @@ -63,7 +63,9 @@
> #define IRQSTAT_CC (0x00000001)
>
> #define CMD_ERR (IRQSTAT_CIE | IRQSTAT_CEBE | IRQSTAT_CCE)
> -#define DATA_ERR (IRQSTAT_DEBE | IRQSTAT_DCE | IRQSTAT_DTOE)
> +#define DATA_ERR (IRQSTAT_DEBE | IRQSTAT_DCE | IRQSTAT_DTOE | \
> + IRQSTAT_DMAE)
> +#define DATA_COMPLETE (IRQSTAT_TC | IRQSTAT_DINT)
>
> #define IRQSTATEN 0x0002e034
> #define IRQSTATEN_DMAE (0x10000000)

I haven't tested this myself, but I got the following issue report
regarding this patch:

Using a SANDISK ULTRA II 8GB card (or alternatively Transcend 16GB or
32GB cards) and trying an mmc write [1] into the upper area of the 8GB
card makes the write hang in 9 of 10 cases. Sometimes even more.
Reverting this patch make these writes work again.

mmc read does work fine, though. Even newer SANDISK Extreme III or
several micro SD cards are working fine.

Any idea?

Best regards

Dirk

[1]

mmc write 0x10800000 70ea40 1