1 files changed, 77 insertions, 16 deletions

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index ed700a5b03ae..976c9d0e8080 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -45,6 +45,10 @@ static unsigned int fmax = 515633;
  *	      is asserted (likewise for RX)
  * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY
  *		  is asserted (likewise for RX)
+ * @broken_blockend: the MCI_DATABLOCKEND is broken on the hardware
+ *		and will not work at all.
+ * @broken_blockend_dma: the MCI_DATABLOCKEND is broken on the hardware when
+ *		using DMA.
  */
 struct variant_data {
 	unsigned int		clkreg;
@@ -52,6 +56,8 @@ struct variant_data {
 	unsigned int		datalength_bits;
 	unsigned int		fifosize;
 	unsigned int		fifohalfsize;
+	bool			broken_blockend;
+	bool			broken_blockend_dma;
 };
 
 static struct variant_data variant_arm = {
@@ -65,6 +71,7 @@ static struct variant_data variant_u300 = {
 	.fifohalfsize		= 8 * 4,
 	.clkreg_enable		= 1 << 13, /* HWFCEN */
 	.datalength_bits	= 16,
+	.broken_blockend_dma	= true,
 };
 
 static struct variant_data variant_ux500 = {
@@ -73,6 +80,7 @@ static struct variant_data variant_ux500 = {
 	.clkreg			= MCI_CLK_ENABLE,
 	.clkreg_enable		= 1 << 14, /* HWFCEN */
 	.datalength_bits	= 24,
+	.broken_blockend	= true,
 };
 /*
  * This must be called with host->lock held
@@ -178,6 +186,8 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
 	host->data = data;
 	host->size = data->blksz * data->blocks;
 	host->data_xfered = 0;
+	host->blockend = false;
+	host->dataend = false;
 
 	mmci_init_sg(host, data);
 
@@ -249,20 +259,9 @@ static void
 mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 	      unsigned int status)
 {
-	if (status & MCI_DATABLOCKEND) {
-		host->data_xfered += data->blksz;
-#ifdef CONFIG_ARCH_U300
-		/*
-		 * On the U300 some signal or other is
-		 * badly routed so that a data write does
-		 * not properly terminate with a MCI_DATAEND
-		 * status flag. This quirk will make writes
-		 * work again.
-		 */
-		if (data->flags & MMC_DATA_WRITE)
-			status |= MCI_DATAEND;
-#endif
-	}
+	struct variant_data *variant = host->variant;
+
+	/* First check for errors */
 	if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
 		dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ (status %08x)\n", status);
 		if (status & MCI_DATACRCFAIL)
@@ -271,7 +270,10 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 			data->error = -ETIMEDOUT;
 		else if (status & (MCI_TXUNDERRUN|MCI_RXOVERRUN))
 			data->error = -EIO;
-		status |= MCI_DATAEND;
+
+		/* Force-complete the transaction */
+		host->blockend = true;
+		host->dataend = true;
 
 		/*
 		 * We hit an error condition.  Ensure that any data
@@ -289,9 +291,64 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 			local_irq_restore(flags);
 		}
 	}
-	if (status & MCI_DATAEND) {
+
+	/*
+	 * On ARM variants in PIO mode, MCI_DATABLOCKEND
+	 * is always sent first, and we increase the
+	 * transfered number of bytes for that IRQ. Then
+	 * MCI_DATAEND follows and we conclude the transaction.
+	 *
+	 * On the Ux500 single-IRQ variant MCI_DATABLOCKEND
+	 * doesn't seem to immediately clear from the status,
+	 * so we can't use it keep count when only one irq is
+	 * used because the irq will hit for other reasons, and
+	 * then the flag is still up. So we use the MCI_DATAEND
+	 * IRQ at the end of the entire transfer because
+	 * MCI_DATABLOCKEND is broken.
+	 *
+	 * In the U300, the IRQs can arrive out-of-order,
+	 * e.g. MCI_DATABLOCKEND sometimes arrives after MCI_DATAEND,
+	 * so for this case we use the flags "blockend" and
+	 * "dataend" to make sure both IRQs have arrived before
+	 * concluding the transaction. (This does not apply
+	 * to the Ux500 which doesn't fire MCI_DATABLOCKEND
+	 * at all.) In DMA mode it suffers from the same problem
+	 * as the Ux500.
+	 */
+	if (status & MCI_DATABLOCKEND) {
+		/*
+		 * Just being a little over-cautious, we do not
+		 * use this progressive update if the hardware blockend
+		 * flag is unreliable: since it can stay high between
+		 * IRQs it will corrupt the transfer counter.
+		 */
+		if (!variant->broken_blockend)
+			host->data_xfered += data->blksz;
+		host->blockend = true;
+	}
+
+	if (status & MCI_DATAEND)
+		host->dataend = true;
+
+	/*
+	 * On variants with broken blockend we shall only wait for dataend,
+	 * on others we must sync with the blockend signal since they can
+	 * appear out-of-order.
+	 */
+	if (host->dataend && (host->blockend || variant->broken_blockend)) {
 		mmci_stop_data(host);
 
+		/* Reset these flags */
+		host->blockend = false;
+		host->dataend = false;
+
+		/*
+		 * Variants with broken blockend flags need to handle the
+		 * end of the entire transfer here.
+		 */
+		if (variant->broken_blockend && !data->error)
+			host->data_xfered += data->blksz * data->blocks;
+
 		if (!data->stop) {
 			mmci_request_end(host, data->mrq);
 		} else {
@@ -841,6 +898,10 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id)
 	}
 
 	mask = MCI_IRQENABLE;
+	/* Don't use the datablockend flag if it's broken */
+	if (variant->broken_blockend)
+		mask &= ~MCI_DATABLOCKEND;
+
 	writel(mask, host->base + MMCIMASK0);
 
 	amba_set_drvdata(dev, mmc);