Revert "mmc: dw_mmc: Extract FIFO data transfer into a separate routine"

The commit 0252924ac6d4 ("mmc: dw_mmc: Extract FIFO data transfer into a
separate routine") unintentionally changed behavior of the FIFO data
transfer routine.

When data is read and size reaches 0 the original loop would wait on
DWMCI_INTMSK_DTO or timeout. The remaining size to read and buf position
is no longer tracked across dwmci_data_transfer_fifo() calls and because
of this an extra call to fifo() and dwmci_fifo_ready() may now trigger a
FIFO underflow timeout error and slows down FIFO reading.

  Buswidth = 4, clock: 50000000
  Sending CMD16
  Sending CMD17
  dwmci_fifo_ready: FIFO underflow timeout
  Sending CMD16
  Sending CMD18
  dwmci_fifo_ready: FIFO underflow timeout
  Sending CMD12
  ## Checking hash(es) for config config-1 ... OK

This reverts commit 0252924ac6d4af69061bb9589d16b30c5bdb7178 to restore
the old working behavior.

Fixes: 0252924ac6d4 ("mmc: dw_mmc: Extract FIFO data transfer into a separate routine")
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Tested-by: Quentin Schulz <quentin.schulz@cherry.de> # RK3588 Tiger
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index 8551eac70185dc414d359cfc67c170043b3f2f9b..e1110cace897ae23c978b63c1963a2ae54789ff0 100644 (file)
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -214,66 +214,24 @@ static unsigned int dwmci_get_timeout(struct mmc *mmc, const unsigned int size)
        return timeout;
 }
 
-static int dwmci_data_transfer_fifo(struct dwmci_host *host,
-                                   struct mmc_data *data, u32 mask)
+static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
 {
-       const u32 int_rx = mask & (DWMCI_INTMSK_RXDR | DWMCI_INTMSK_DTO);
-       const u32 int_tx = mask & DWMCI_INTMSK_TXDR;
+       struct mmc *mmc = host->mmc;
        int ret = 0;
-       u32 len = 0, size, i;
-       u32 *buf;
-
-       size = (data->blocksize * data->blocks) / 4;
-       if (!host->fifo_mode || !size)
-               return 0;
+       u32 timeout, mask, size, i, len = 0;
+       u32 *buf = NULL;
+       ulong start = get_timer(0);
 
+       size = data->blocksize * data->blocks;
        if (data->flags == MMC_DATA_READ)
                buf = (unsigned int *)data->dest;
        else
                buf = (unsigned int *)data->src;
 
-       if (data->flags == MMC_DATA_READ && int_rx) {
-               dwmci_writel(host, DWMCI_RINTSTS, int_rx);
-               while (size) {
-                       ret = dwmci_fifo_ready(host, DWMCI_FIFO_EMPTY, &len);
-                       if (ret < 0)
-                               break;
-
-                       len = (len >> DWMCI_FIFO_SHIFT) & DWMCI_FIFO_MASK;
-                       len = min(size, len);
-                       for (i = 0; i < len; i++)
-                               *buf++ = dwmci_readl(host, DWMCI_DATA);
-                       size = size > len ? (size - len) : 0;
-               }
-       } else if (data->flags == MMC_DATA_WRITE && int_tx) {
-               while (size) {
-                       ret = dwmci_fifo_ready(host, DWMCI_FIFO_FULL, &len);
-                       if (ret < 0)
-                               break;
-
-                       len = host->fifo_depth - ((len >> DWMCI_FIFO_SHIFT) &
-                                                 DWMCI_FIFO_MASK);
-                       len = min(size, len);
-                       for (i = 0; i < len; i++)
-                               dwmci_writel(host, DWMCI_DATA, *buf++);
-                       size = size > len ? (size - len) : 0;
-               }
-               dwmci_writel(host, DWMCI_RINTSTS, DWMCI_INTMSK_TXDR);
-       }
-
-       return ret;
-}
-
-static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
-{
-       struct mmc *mmc = host->mmc;
-       int ret = 0;
-       u32 timeout, mask, size;
-       ulong start = get_timer(0);
-
-       size = data->blocksize * data->blocks;
        timeout = dwmci_get_timeout(mmc, size);
 
+       size /= 4;
+
        for (;;) {
                mask = dwmci_readl(host, DWMCI_RINTSTS);
                /* Error during data transfer */
@@ -283,7 +241,50 @@ static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
                        break;
                }
 
-               ret = dwmci_data_transfer_fifo(host, data, mask);
+               if (host->fifo_mode && size) {
+                       len = 0;
+                       if (data->flags == MMC_DATA_READ &&
+                           (mask & (DWMCI_INTMSK_RXDR | DWMCI_INTMSK_DTO))) {
+                               dwmci_writel(host, DWMCI_RINTSTS,
+                                            mask & (DWMCI_INTMSK_RXDR |
+                                                    DWMCI_INTMSK_DTO));
+                               while (size) {
+                                       ret = dwmci_fifo_ready(host,
+                                                       DWMCI_FIFO_EMPTY,
+                                                       &len);
+                                       if (ret < 0)
+                                               break;
+
+                                       len = (len >> DWMCI_FIFO_SHIFT) &
+                                                   DWMCI_FIFO_MASK;
+                                       len = min(size, len);
+                                       for (i = 0; i < len; i++)
+                                               *buf++ =
+                                               dwmci_readl(host, DWMCI_DATA);
+                                       size = size > len ? (size - len) : 0;
+                               }
+                       } else if (data->flags == MMC_DATA_WRITE &&
+                                  (mask & DWMCI_INTMSK_TXDR)) {
+                               while (size) {
+                                       ret = dwmci_fifo_ready(host,
+                                                       DWMCI_FIFO_FULL,
+                                                       &len);
+                                       if (ret < 0)
+                                               break;
+
+                                       len = host->fifo_depth - ((len >>
+                                                  DWMCI_FIFO_SHIFT) &
+                                                  DWMCI_FIFO_MASK);
+                                       len = min(size, len);
+                                       for (i = 0; i < len; i++)
+                                               dwmci_writel(host, DWMCI_DATA,
+                                                            *buf++);
+                                       size = size > len ? (size - len) : 0;
+                               }
+                               dwmci_writel(host, DWMCI_RINTSTS,
+                                            DWMCI_INTMSK_TXDR);
+                       }
+               }
 
                /* Data arrived correctly */
                if (mask & DWMCI_INTMSK_DTO) {