[U-Boot] [PATCH v2 4/4] mmc: sdhci: add the udelay for completed post-request

Andy Fleming
2012-08-30T21:55:09Z

On Thu, Jul 26, 2012 at 7:33 PM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> To ensure that complete the request, add udelay(100).
> Also increased the timeout value to 10000.
> (Because timeout value is short, there is the case that didn't transfer data)
>
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> ---
> drivers/mmc/sdhci.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
> index ac39e48..f71a14b 100644
> --- a/drivers/mmc/sdhci.c
> +++ b/drivers/mmc/sdhci.c
> @@ -83,7 +83,7 @@ static int sdhci_transfer_data(struct sdhci_host *host, struct mmc_data *data,
> {
> unsigned int stat, rdy, mask, timeout, block = 0;
>
> - timeout = 10000;
> + timeout = 100000;
> rdy = SDHCI_INT_SPACE_AVAIL | SDHCI_INT_DATA_AVAIL;
> mask = SDHCI_DATA_AVAILABLE | SDHCI_SPACE_AVAILABLE;
> do {
> @@ -239,6 +239,7 @@ int sdhci_send_command(struct mmc *mmc, struct mmc_cmd *cmd,
> if ((host->quirks & SDHCI_QUIRK_32BIT_DMA_ADDR) &&
> !is_aligned && (data->flags == MMC_DATA_READ))
> memcpy(data->dest, aligned_buffer, trans_bytes);
> + udelay(100);

These sorts of changes (both the increased timeout, and the udelay)
look very much like attempting to use time to substitute for proper
coherency assurances. What "request" is this udelay allowing to
finish?

Andy