ARM: 6632/3: mmci: stop using the blockend interrupts

Implement a suggestion from Russell to drop the use of blockend
interrupts altogether and instead rely on the data counter.

Tested with error-free cards on U300, U8500 and RealView PB1176.

Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 56302282566777daddc5c63bb2eff3582b0ba062..2de12fe155da2a00d158c67fc138e25a002888a7 100644 (file)
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -46,10 +46,6 @@ 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.
  * @sdio: variant supports SDIO
  * @st_clkdiv: true if using a ST-specific clock divider algorithm
  */
@@ -59,8 +55,6 @@ struct variant_data {
        unsigned int            datalength_bits;
        unsigned int            fifosize;
        unsigned int            fifohalfsize;
-       bool                    broken_blockend;
-       bool                    broken_blockend_dma;
        bool                    sdio;
        bool                    st_clkdiv;
 };
@@ -76,7 +70,6 @@ static struct variant_data variant_u300 = {
        .fifohalfsize           = 8 * 4,
        .clkreg_enable          = 1 << 13, /* HWFCEN */
        .datalength_bits        = 16,
-       .broken_blockend_dma    = true,
        .sdio                   = true,
 };
 
@@ -86,7 +79,6 @@ static struct variant_data variant_ux500 = {
        .clkreg                 = MCI_CLK_ENABLE,
        .clkreg_enable          = 1 << 14, /* HWFCEN */
        .datalength_bits        = 24,
-       .broken_blockend        = true,
        .sdio                   = true,
        .st_clkdiv              = true,
 };
@@ -210,8 +202,6 @@ 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);
 
@@ -288,21 +278,26 @@ static void
 mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
              unsigned int status)
 {
-       struct variant_data *variant = host->variant;
-
        /* First check for errors */
        if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
+               u32 remain, success;
+
+               /* Calculate how far we are into the transfer */
+               remain = readl(host->base + MMCIDATACNT) << 2;
+               success = data->blksz * data->blocks - remain;
+
                dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ (status %08x)\n", status);
-               if (status & MCI_DATACRCFAIL)
+               if (status & MCI_DATACRCFAIL) {
+                       /* Last block was not successful */
+                       host->data_xfered = ((success / data->blksz) - 1 * data->blksz);
                        data->error = -EILSEQ;
-               else if (status & MCI_DATATIMEOUT)
+               } else if (status & MCI_DATATIMEOUT) {
+                       host->data_xfered = success;
                        data->error = -ETIMEDOUT;
-               else if (status & (MCI_TXUNDERRUN|MCI_RXOVERRUN))
+               } else if (status & (MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
+                       host->data_xfered = success;
                        data->error = -EIO;
-
-               /* Force-complete the transaction */
-               host->blockend = true;
-               host->dataend = true;
+               }
 
                /*
                 * We hit an error condition.  Ensure that any data
@@ -321,61 +316,14 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
                }
        }
 
-       /*
-        * 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;
+       if (status & MCI_DATABLOCKEND)
+               dev_err(mmc_dev(host->mmc), "stray MCI_DATABLOCKEND interrupt\n");
 
-       /*
-        * 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)) {
+       if (status & MCI_DATAEND) {
                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)
+               if (!data->error)
+                       /* The error clause is handled above, success! */
                        host->data_xfered += data->blksz * data->blocks;
 
                if (!data->stop) {
@@ -770,7 +718,6 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id)
        struct variant_data *variant = id->data;
        struct mmci_host *host;
        struct mmc_host *mmc;
-       unsigned int mask;
        int ret;
 
        /* must have platform data */
@@ -951,12 +898,7 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id)
                        goto irq0_free;
        }
 
-       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);
+       writel(MCI_IRQENABLE, host->base + MMCIMASK0);
 
        amba_set_drvdata(dev, mmc);
 

diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index df06f01aac8953a482bb25fdf3261f2496b6504c..c1df7b82d36cc63f5f420ac71ff68cdc120ccee5 100644 (file)
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -137,7 +137,7 @@
 #define MCI_IRQENABLE  \
        (MCI_CMDCRCFAILMASK|MCI_DATACRCFAILMASK|MCI_CMDTIMEOUTMASK|     \
        MCI_DATATIMEOUTMASK|MCI_TXUNDERRUNMASK|MCI_RXOVERRUNMASK|       \
-       MCI_CMDRESPENDMASK|MCI_CMDSENTMASK|MCI_DATABLOCKENDMASK)
+       MCI_CMDRESPENDMASK|MCI_CMDSENTMASK)
 
 /* These interrupts are directed to IRQ1 when two IRQ lines are available */
 #define MCI_IRQ1MASK \
@@ -177,9 +177,6 @@ struct mmci_host {
        struct timer_list       timer;
        unsigned int            oldstat;
 
-       bool                    blockend;
-       bool                    dataend;
-
        /* pio stuff */
        struct sg_mapping_iter  sg_miter;
        unsigned int            size;