sdhci: don't check block count for progress
authorPierre Ossman <drzeus@drzeus.cx>
Fri, 18 Apr 2008 18:41:49 +0000 (20:41 +0200)
committerPierre Ossman <drzeus@drzeus.cx>
Tue, 15 Jul 2008 12:14:39 +0000 (14:14 +0200)
The specification is insufficiently strict when it comes to how the
hardware should update the block count register, making it useless
for checking transfer progress.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
drivers/mmc/host/sdhci.c

index b413aa6c246b938649f47e63a2af5482f76fdc11..9b06c6042d971aa1f0264a74eda0924f1cb0de85 100644 (file)
@@ -567,7 +567,6 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 static void sdhci_finish_data(struct sdhci_host *host)
 {
        struct mmc_data *data;
-       u16 blocks;
 
        BUG_ON(!host->data);
 
@@ -580,20 +579,16 @@ static void sdhci_finish_data(struct sdhci_host *host)
        }
 
        /*
-        * Controller doesn't count down when in single block mode.
+        * The specification states that the block count register must
+        * be updated, but it does not specify at what point in the
+        * data flow. That makes the register entirely useless to read
+        * back so we have to assume that nothing made it to the card
+        * in the event of an error.
         */
-       if (data->blocks == 1)
-               blocks = (data->error == 0) ? 0 : 1;
+       if (data->error)
+               data->bytes_xfered = 0;
        else
-               blocks = readw(host->ioaddr + SDHCI_BLOCK_COUNT);
-       data->bytes_xfered = data->blksz * (data->blocks - blocks);
-
-       if (!data->error && blocks) {
-               printk(KERN_ERR "%s: Controller signalled completion even "
-                       "though there were blocks left.\n",
-                       mmc_hostname(host->mmc));
-               data->error = -EIO;
-       }
+               data->bytes_xfered = data->blksz * data->blocks;
 
        if (data->stop) {
                /*
@@ -1466,7 +1461,7 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
        mmc->ops = &sdhci_ops;
        mmc->f_min = host->max_clk / 256;
        mmc->f_max = host->max_clk;
-       mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_MULTIWRITE | MMC_CAP_SDIO_IRQ;
+       mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
 
        if (caps & SDHCI_CAN_DO_HISPD)
                mmc->caps |= MMC_CAP_SD_HIGHSPEED;