From: Pierre Ossman <drzeus@drzeus.cx>
Date: Fri, 18 Apr 2008 18:41:49 +0000 (+0200)
Subject: sdhci: don't check block count for progress
X-Git-Tag: v2.6.27-rc1~1047^2~67
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=c9b74c5b8fb807187f6b1db09012828fcd2d7e73;p=linux-2.6-omap-h63xx.git

sdhci: don't check block count for progress

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>
---

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index b413aa6c246..9b06c6042d9 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -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;