A-003500: False ADMA Error might be reported when ADMA is used for 
multiple block read command with Stop at Block Gap. If PROCTL[SABGREQ] 
is set when the particular block's data is received by the System side 
logic before entire block(with CRC) data is received by the SD side 
logic, and also if ADMA descriptor line is fetched at the same time, 
then DMA engine might report false ADMA error. eSDHC might not be able 
to Continue(PROCTL[CREQ]=1)after Stop at Block Gap.
This issue will impact the eSDHC IP VVN2.3.

Signed-off-by: Haijun Zhang <haijun.zh...@freescale.com>
Signed-off-by: Jerry Huang <chang-ming.hu...@freescale.com>
Acked-by: Anton Vorontsov <cbouatmai...@gmail.com>
CC: Chris Ball <c...@laptop.org>
---
changes for v5:
        - Add comment, no other changes

changes for v4:
        - Correct inconsistent issue

changes for v3:
        - Correct the if statement in function workground

changes for v2:
        - Invert the condition of the if statement in function workground

 drivers/mmc/host/sdhci-of-esdhc.c |   52 ++++++++++++++++++++++++++++++++++++-
 drivers/mmc/host/sdhci.c          |    2 +
 drivers/mmc/host/sdhci.h          |    5 +++-
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-of-esdhc.c 
b/drivers/mmc/host/sdhci-of-esdhc.c
index 1cba55a..9c6bf78 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -21,6 +21,7 @@
 #include "sdhci-esdhc.h"
 
 #define VENDOR_V_22    0x12
+#define VENDOR_V_23    0x13
 static u32 esdhc_readl(struct sdhci_host *host, int reg)
 {
        u32 ret;
@@ -83,6 +84,18 @@ static u8 esdhc_readb(struct sdhci_host *host, int reg)
        return ret;
 }
 
+static void esdhc_writel(struct sdhci_host *host, u32 val, int reg)
+{
+       /*
+        * Enable IRQSTATEN[BGESEN] is just to set IRQSTAT[BGE]
+        * when SYSCTL[RSTD]) is set for some special operations.
+        * No any impact other operation.
+        */
+       if (reg == SDHCI_INT_ENABLE)
+               val |= SDHCI_INT_BLK_GAP;
+       sdhci_be32bs_writel(host, val, reg);
+}
+
 static void esdhc_writew(struct sdhci_host *host, u16 val, int reg)
 {
        if (reg == SDHCI_BLOCK_SIZE) {
@@ -138,6 +151,42 @@ static unsigned int esdhc_of_get_min_clock(struct 
sdhci_host *host)
        return of_host->clock / 256 / 16;
 }
 
+/*
+ * For Abort or Suspend after Stop at Block Gap, ignore the ADMA
+ * error(IRQSTAT[ADMAE]) if both Transfer Complete(IRQSTAT[TC])
+ * and Block Gap Event(IRQSTAT[BGE]) are also set.
+ * For Continue, apply soft reset for data(SYSCTL[RSTD]);
+ * and re-issue the entire read
+ * transaction from beginning.
+ */
+static void esdhci_of_adma_workaround(struct sdhci_host *host, u32 intmask)
+{
+       u32 tmp;
+       bool applicable;
+       dma_addr_t dmastart;
+       dma_addr_t dmanow;
+
+       tmp = in_be32(host->ioaddr + SDHCI_SLOT_INT_STATUS);
+       tmp = (tmp & SDHCI_VENDOR_VER_MASK) >> SDHCI_VENDOR_VER_SHIFT;
+
+       applicable = (intmask & SDHCI_INT_DATA_END) &&
+                       (intmask & SDHCI_INT_BLK_GAP) &&
+                       (tmp == VENDOR_V_23);
+       if (!applicable)
+               return;
+
+       host->data->error = 0;
+       dmastart = sg_dma_address(host->data->sg);
+       dmanow = dmastart + host->data->bytes_xfered;
+       /*
+        * Force update to the next DMA block boundary.
+        */
+       dmanow = (dmanow & ~(SDHCI_DEFAULT_BOUNDARY_SIZE - 1)) +
+               SDHCI_DEFAULT_BOUNDARY_SIZE;
+       host->data->bytes_xfered = dmanow - dmastart;
+       sdhci_writel(host, dmanow, SDHCI_DMA_ADDRESS);
+}
+
 #ifdef CONFIG_PM
 static u32 esdhc_proctl;
 static void esdhc_of_suspend(struct sdhci_host *host)
@@ -164,7 +213,7 @@ struct sdhci_of_data sdhci_esdhc = {
                .read_l = esdhc_readl,
                .read_w = esdhc_readw,
                .read_b = esdhc_readb,
-               .write_l = sdhci_be32bs_writel,
+               .write_l = esdhc_writel,
                .write_w = esdhc_writew,
                .write_b = esdhc_writeb,
                .set_clock = esdhc_set_clock,
@@ -175,5 +224,6 @@ struct sdhci_of_data sdhci_esdhc = {
                .platform_suspend = esdhc_of_suspend,
                .platform_resume = esdhc_of_resume,
 #endif
+               .adma_workaround = esdhci_of_adma_workaround,
        },
 };
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 684f1a4..3d9365a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2143,6 +2143,8 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 
intmask)
                printk(KERN_ERR "%s: ADMA error\n", mmc_hostname(host->mmc));
                sdhci_show_adma_error(host);
                host->data->error = -EIO;
+               if (host->ops->adma_workaround)
+                       host->ops->adma_workaround(host, intmask);
        }
 
        if (host->data->error)
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 209f707..138d8fc 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -120,6 +120,7 @@
 #define SDHCI_SIGNAL_ENABLE    0x38
 #define  SDHCI_INT_RESPONSE    0x00000001
 #define  SDHCI_INT_DATA_END    0x00000002
+#define  SDHCI_INT_BLK_GAP     0x00000004
 #define  SDHCI_INT_DMA_END     0x00000008
 #define  SDHCI_INT_SPACE_AVAIL 0x00000010
 #define  SDHCI_INT_DATA_AVAIL  0x00000020
@@ -146,7 +147,8 @@
 #define  SDHCI_INT_DATA_MASK   (SDHCI_INT_DATA_END | SDHCI_INT_DMA_END | \
                SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL | \
                SDHCI_INT_DATA_TIMEOUT | SDHCI_INT_DATA_CRC | \
-               SDHCI_INT_DATA_END_BIT | SDHCI_INT_ADMA_ERROR)
+               SDHCI_INT_DATA_END_BIT | SDHCI_INT_ADMA_ERROR | \
+               SDHCI_INT_BLK_GAP)
 #define SDHCI_INT_ALL_MASK     ((unsigned int)-1)
 
 #define SDHCI_ACMD12_ERR       0x3C
@@ -275,6 +277,7 @@ struct sdhci_ops {
        int     (*set_uhs_signaling)(struct sdhci_host *host, unsigned int uhs);
        void    (*platform_suspend)(struct sdhci_host *host);
        void    (*platform_resume)(struct sdhci_host *host);
+       void    (*adma_workaround)(struct sdhci_host *host, u32 intmask);
 
 };
 
-- 
1.7.0.4


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