ARM: mx3: Fix a race condition in mxcmmc

[safe/jmp/linux-2.6] / drivers / mmc / host / mxcmmc.c

diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c
index 44a53ee..ec18e3b 100644 (file)
--- a/drivers/mmc/host/mxcmmc.c
+++ b/drivers/mmc/host/mxcmmc.c
@@ -119,6 +119,7 @@ struct mxcmci_host {
        int                     detect_irq;
        int                     dma;
        int                     do_dma;
+       int                     use_sdio;
        unsigned int            power_mode;
        struct imxmmc_platform_data *pdata;
 
@@ -138,6 +139,7 @@ struct mxcmci_host {
        int                     clock;
 
        struct work_struct      datawork;
+       spinlock_t              lock;
 };
 
 static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
@@ -226,6 +228,9 @@ static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
 static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
                unsigned int cmdat)
 {
+       u32 int_cntr;
+       unsigned long flags;
+
        WARN_ON(host->cmd != NULL);
        host->cmd = cmd;
 
@@ -249,12 +254,16 @@ static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
                return -EINVAL;
        }
 
+       int_cntr = INT_END_CMD_RES_EN;
+
        if (mxcmci_use_dma(host))
-               writel(INT_READ_OP_EN | INT_WRITE_OP_DONE_EN |
-                               INT_END_CMD_RES_EN,
-                               host->base + MMC_REG_INT_CNTR);
-       else
-               writel(INT_END_CMD_RES_EN, host->base + MMC_REG_INT_CNTR);
+               int_cntr |= INT_READ_OP_EN | INT_WRITE_OP_DONE_EN;
+
+       spin_lock_irqsave(&host->lock, flags);
+       if (host->use_sdio)
+               int_cntr |= INT_SDIO_IRQ_EN;
+       writel(int_cntr, host->base + MMC_REG_INT_CNTR);
+       spin_unlock_irqrestore(&host->lock, flags);
 
        writew(cmd->opcode, host->base + MMC_REG_CMD);
        writel(cmd->arg, host->base + MMC_REG_ARG);
@@ -266,7 +275,14 @@ static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
 static void mxcmci_finish_request(struct mxcmci_host *host,
                struct mmc_request *req)
 {
-       writel(0, host->base + MMC_REG_INT_CNTR);
+       u32 int_cntr = 0;
+       unsigned long flags;
+
+       spin_lock_irqsave(&host->lock, flags);
+       if (host->use_sdio)
+               int_cntr |= INT_SDIO_IRQ_EN;
+       writel(int_cntr, host->base + MMC_REG_INT_CNTR);
+       spin_unlock_irqrestore(&host->lock, flags);
 
        host->req = NULL;
        host->cmd = NULL;
@@ -473,6 +489,9 @@ static void mxcmci_datawork(struct work_struct *work)
        struct mxcmci_host *host = container_of(work, struct mxcmci_host,
                                                  datawork);
        int datastat = mxcmci_transfer_data(host);
+
+       writel(STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
+               host->base + MMC_REG_STATUS);
        mxcmci_finish_data(host, datastat);
 
        if (host->req->stop) {
@@ -532,15 +551,35 @@ static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
 static irqreturn_t mxcmci_irq(int irq, void *devid)
 {
        struct mxcmci_host *host = devid;
+       unsigned long flags;
+       bool sdio_irq;
        u32 stat;
 
        stat = readl(host->base + MMC_REG_STATUS);
-       writel(stat, host->base + MMC_REG_STATUS);
+       writel(stat & ~(STATUS_SDIO_INT_ACTIVE | STATUS_DATA_TRANS_DONE |
+                       STATUS_WRITE_OP_DONE), host->base + MMC_REG_STATUS);
 
        dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
 
+       spin_lock_irqsave(&host->lock, flags);
+       sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
+       spin_unlock_irqrestore(&host->lock, flags);
+
+#ifdef HAS_DMA
+       if (mxcmci_use_dma(host) &&
+           (stat & (STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE)))
+               writel(STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
+                       host->base + MMC_REG_STATUS);
+#endif
+
+       if (sdio_irq) {
+               writel(STATUS_SDIO_INT_ACTIVE, host->base + MMC_REG_STATUS);
+               mmc_signal_sdio_irq(host->mmc);
+       }
+
        if (stat & STATUS_END_CMD_RESP)
                mxcmci_cmd_done(host, stat);
+
 #ifdef HAS_DMA
        if (mxcmci_use_dma(host) &&
                  (stat & (STATUS_DATA_TRANS_DONE | STATUS_WRITE_OP_DONE)))
@@ -677,11 +716,46 @@ static int mxcmci_get_ro(struct mmc_host *mmc)
        return -ENOSYS;
 }
 
+static void mxcmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+       struct mxcmci_host *host = mmc_priv(mmc);
+       unsigned long flags;
+       u32 int_cntr;
+
+       spin_lock_irqsave(&host->lock, flags);
+       host->use_sdio = enable;
+       int_cntr = readl(host->base + MMC_REG_INT_CNTR);
+
+       if (enable)
+               int_cntr |= INT_SDIO_IRQ_EN;
+       else
+               int_cntr &= ~INT_SDIO_IRQ_EN;
+
+       writel(int_cntr, host->base + MMC_REG_INT_CNTR);
+       spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void mxcmci_init_card(struct mmc_host *host, struct mmc_card *card)
+{
+       /*
+        * MX3 SoCs have a silicon bug which corrupts CRC calculation of
+        * multi-block transfers when connected SDIO peripheral doesn't
+        * drive the BUSY line as required by the specs.
+        * One way to prevent this is to only allow 1-bit transfers.
+        */
+
+       if (cpu_is_mx3() && card->type == MMC_TYPE_SDIO)
+               host->caps &= ~MMC_CAP_4_BIT_DATA;
+       else
+               host->caps |= MMC_CAP_4_BIT_DATA;
+}
 
 static const struct mmc_host_ops mxcmci_ops = {
-       .request        = mxcmci_request,
-       .set_ios        = mxcmci_set_ios,
-       .get_ro         = mxcmci_get_ro,
+       .request                = mxcmci_request,
+       .set_ios                = mxcmci_set_ios,
+       .get_ro                 = mxcmci_get_ro,
+       .enable_sdio_irq        = mxcmci_enable_sdio_irq,
+       .init_card              = mxcmci_init_card,
 };
 
 static int mxcmci_probe(struct platform_device *pdev)
@@ -709,7 +783,7 @@ static int mxcmci_probe(struct platform_device *pdev)
        }
 
        mmc->ops = &mxcmci_ops;
-       mmc->caps = MMC_CAP_4_BIT_DATA;
+       mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
 
        /* MMC core transfer sizes tunable parameters */
        mmc->max_hw_segs = 64;
@@ -728,6 +802,7 @@ static int mxcmci_probe(struct platform_device *pdev)
 
        host->mmc = mmc;
        host->pdata = pdev->dev.platform_data;
+       spin_lock_init(&host->lock);
 
        if (host->pdata && host->pdata->ocr_avail)
                mmc->ocr_avail = host->pdata->ocr_avail;