sdhci: handle data interrupts during command

It is fully legal for a controller to start issuing data related
interrupts before it has signalled that the command has completed.
Make sure the driver actually can handle this.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

2 files changed, 22 insertions, 7 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2b327b40fa81..f8fc0a98b8c4 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -385,6 +385,9 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
         BUG_ON(data->blksz > host->mmc->max_blk_size);
         BUG_ON(data->blocks > 65535);
 
+        host->data = data;
+        host->data_early = 0;
+
         /* timeout in us */
         target_timeout = data->timeout_ns / 1000 +
                 data->timeout_clks / host->clock;
@@ -443,11 +446,11 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 {
         u16 mode;
 
-        WARN_ON(host->data);
-
         if (data == NULL)
                 return;
 
+        WARN_ON(!host->data);
+
         mode = SDHCI_TRNS_BLK_CNT_EN;
         if (data->blocks > 1)
                 mode |= SDHCI_TRNS_MULTI;
@@ -600,9 +603,10 @@ static void sdhci_finish_command(struct sdhci_host *host)
 
         host->cmd->error = MMC_ERR_NONE;
 
-        if (host->cmd->data)
-                host->data = host->cmd->data;
-        else
+        if (host->data && host->data_early)
+                sdhci_finish_data(host);
+
+        if (!host->cmd->data)
                 tasklet_schedule(&host->finish_tasklet);
 
         host->cmd = NULL;
@@ -991,8 +995,18 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
                         writel(readl(host->ioaddr + SDHCI_DMA_ADDRESS),
                                 host->ioaddr + SDHCI_DMA_ADDRESS);
 
-                if (intmask & SDHCI_INT_DATA_END)
-                        sdhci_finish_data(host);
+                if (intmask & SDHCI_INT_DATA_END) {
+                        if (host->cmd) {
+                                /*
+                                 * Data managed to finish before the
+                                 * command completed. Make sure we do
+                                 * things in the proper order.
+                                 */
+                                host->data_early = 1;
+                        } else {
+                                sdhci_finish_data(host);
+                        }
+                }
         }
 }
 
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index d157776c1149..e28987d6d2eb 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -182,6 +182,7 @@ struct sdhci_host {
         struct mmc_request      *mrq;           /* Current request */
         struct mmc_command      *cmd;           /* Current command */
         struct mmc_data         *data;          /* Current data request */
+        int                     data_early:1;   /* Data finished before cmd */
 
         struct scatterlist      *cur_sg;        /* We're working on this */
         int                     num_sg;         /* Entries left */