mmc: dw_mmc: Calculate timeout from transfer length

The current 4-minute data transfer timeout is misleading and broken.
Instead of such a long wait, calculate the timeout duration based on
the length of the data transfer. The current formula is the transfer
length in bits, divided by a multiplication of bus frequency in Hz,
bus width, DDR mode and converted the mSec. The value is bounded from
the bottom to 1000 mSec.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Simon Glass <sjg@chromium.org>

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index 93a836e..d4976ac 100644 (file)
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -114,22 +114,40 @@ static int dwmci_fifo_ready(struct dwmci_host *host, u32 bit, u32 *len)
        return 0;
 }
 
+static unsigned int dwmci_get_timeout(struct mmc *mmc, const unsigned int size)
+{
+       unsigned int timeout;
+
+       timeout = size * 8 * 1000;      /* counting in bits and msec */
+       timeout *= 2;                   /* wait twice as long */
+       timeout /= mmc->clock;
+       timeout /= mmc->bus_width;
+       timeout /= mmc->ddr_mode ? 2 : 1;
+       timeout = (timeout < 1000) ? 1000 : timeout;
+
+       return timeout;
+}
+
 static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
 {
+       struct mmc *mmc = host->mmc;
        int ret = 0;
-       u32 timeout = 240000;
-       u32 mask, size, i, len = 0;
+       u32 timeout, mask, size, i, len = 0;
        u32 *buf = NULL;
        ulong start = get_timer(0);
        u32 fifo_depth = (((host->fifoth_val & RX_WMARK_MASK) >>
                            RX_WMARK_SHIFT) + 1) * 2;
 
-       size = data->blocksize * data->blocks / 4;
+       size = data->blocksize * data->blocks;
        if (data->flags == MMC_DATA_READ)
                buf = (unsigned int *)data->dest;
        else
                buf = (unsigned int *)data->src;
 
+       timeout = dwmci_get_timeout(mmc, size);
+
+       size /= 4;
+
        for (;;) {
                mask = dwmci_readl(host, DWMCI_RINTSTS);
                /* Error during data transfer. */