omap_hsmmc: Change while(); loops with finite version

Replace the infinite 'while() ;' loops
with a finite loop version.

Signed-off-by: Jean Pihet <jpihet@mvista.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 8d21a07..a631c81 100644 (file)
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -376,6 +376,32 @@ static void mmc_omap_report_irq(struct mmc_omap_host *host, u32 status)
 }
 #endif  /* CONFIG_MMC_DEBUG */
 
+/*
+ * MMC controller internal state machines reset
+ *
+ * Used to reset command or data internal state machines, using respectively
+ *  SRC or SRD bit of SYSCTL register
+ * Can be called from interrupt context
+ */
+static inline void mmc_omap_reset_controller_fsm(struct mmc_omap_host *host,
+               unsigned long bit)
+{
+       unsigned long i = 0;
+       unsigned long limit = (loops_per_jiffy *
+                               msecs_to_jiffies(MMC_TIMEOUT_MS));
+
+       OMAP_HSMMC_WRITE(host->base, SYSCTL,
+                        OMAP_HSMMC_READ(host->base, SYSCTL) | bit);
+
+       while ((OMAP_HSMMC_READ(host->base, SYSCTL) & bit) &&
+               (i++ < limit))
+               cpu_relax();
+
+       if (OMAP_HSMMC_READ(host->base, SYSCTL) & bit)
+               dev_err(mmc_dev(host->mmc),
+                       "Timeout waiting on controller reset in %s\n",
+                       __func__);
+}
 
 /*
  * MMC controller IRQ handler
@@ -404,13 +430,7 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id)
                        (status & CMD_CRC)) {
                        if (host->cmd) {
                                if (status & CMD_TIMEOUT) {
-                                       OMAP_HSMMC_WRITE(host->base, SYSCTL,
-                                               OMAP_HSMMC_READ(host->base,
-                                                               SYSCTL) | SRC);
-                                       while (OMAP_HSMMC_READ(host->base,
-                                                       SYSCTL) & SRC)
-                                               ;
-
+                                       mmc_omap_reset_controller_fsm(host, SRC);
                                        host->cmd->error = -ETIMEDOUT;
                                } else {
                                        host->cmd->error = -EILSEQ;
@@ -419,12 +439,7 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id)
                        }
                        if (host->data) {
                                mmc_dma_cleanup(host);
-                               OMAP_HSMMC_WRITE(host->base, SYSCTL,
-                                       OMAP_HSMMC_READ(host->base,
-                                                       SYSCTL) | SRD);
-                               while (OMAP_HSMMC_READ(host->base,
-                                               SYSCTL) & SRD)
-                                       ;
+                               mmc_omap_reset_controller_fsm(host, SRD);
                        }
                }
                if ((status & DATA_TIMEOUT) ||
@@ -434,12 +449,7 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id)
                                        mmc_dma_cleanup(host);
                                else
                                        host->data->error = -EILSEQ;
-                               OMAP_HSMMC_WRITE(host->base, SYSCTL,
-                                       OMAP_HSMMC_READ(host->base,
-                                                       SYSCTL) | SRD);
-                               while (OMAP_HSMMC_READ(host->base,
-                                               SYSCTL) & SRD)
-                                       ;
+                               mmc_omap_reset_controller_fsm(host, SRD);
                                end_trans = 1;
                        }
                }
@@ -547,11 +557,7 @@ static void mmc_omap_detect(struct work_struct *work)
        if (host->carddetect) {
                mmc_detect_change(host->mmc, (HZ * 200) / 1000);
        } else {
-               OMAP_HSMMC_WRITE(host->base, SYSCTL,
-                       OMAP_HSMMC_READ(host->base, SYSCTL) | SRD);
-               while (OMAP_HSMMC_READ(host->base, SYSCTL) & SRD)
-                       ;
-
+               mmc_omap_reset_controller_fsm(host, SRD);
                mmc_detect_change(host->mmc, (HZ * 50) / 1000);
        }
 }