scsi: ufs: verify hba controller hce reg value

Sometimes due to hw issues it takes some time to the
host controller register to update. In order to verify the register
has updated, a polling is done until its value is set.

In addition the functions ufshcd_hba_stop() and
ufshcd_wait_for_register() was updated with an additional input
parameter, indicating the timeout between reads will
be done by sleeping or spinning the cpu.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Raviv Shvili <rshvili@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 3400ceb..80031e6 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -240,11 +240,13 @@ static inline void ufshcd_disable_irq(struct ufs_hba *hba)
  * @val - wait condition
  * @interval_us - polling interval in microsecs
  * @timeout_ms - timeout in millisecs
+ * @can_sleep - perform sleep or just spin
  *
  * Returns -ETIMEDOUT on error, zero on success
  */
-static int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
-               u32 val, unsigned long interval_us, unsigned long timeout_ms)
+int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+                               u32 val, unsigned long interval_us,
+                               unsigned long timeout_ms, bool can_sleep)
 {
        int err = 0;
        unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
@@ -253,9 +255,10 @@ static int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
        val = val & mask;
 
        while ((ufshcd_readl(hba, reg) & mask) != val) {
-               /* wakeup within 50us of expiry */
-               usleep_range(interval_us, interval_us + 50);
-
+               if (can_sleep)
+                       usleep_range(interval_us, interval_us + 50);
+               else
+                       udelay(interval_us);
                if (time_after(jiffies, timeout)) {
                        if ((ufshcd_readl(hba, reg) & mask) != val)
                                err = -ETIMEDOUT;
@@ -1459,7 +1462,7 @@ ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
         */
        err = ufshcd_wait_for_register(hba,
                        REG_UTP_TRANSFER_REQ_DOOR_BELL,
-                       mask, ~mask, 1000, 1000);
+                       mask, ~mask, 1000, 1000, true);
 
        return err;
 }
@@ -2815,6 +2818,23 @@ out:
 }
 
 /**
+ * ufshcd_hba_stop - Send controller to reset state
+ * @hba: per adapter instance
+ * @can_sleep: perform sleep or just spin
+ */
+static inline void ufshcd_hba_stop(struct ufs_hba *hba, bool can_sleep)
+{
+       int err;
+
+       ufshcd_writel(hba, CONTROLLER_DISABLE,  REG_CONTROLLER_ENABLE);
+       err = ufshcd_wait_for_register(hba, REG_CONTROLLER_ENABLE,
+                                       CONTROLLER_ENABLE, CONTROLLER_DISABLE,
+                                       10, 1, can_sleep);
+       if (err)
+               dev_err(hba->dev, "%s: Controller disable failed\n", __func__);
+}
+
+/**
  * ufshcd_hba_enable - initialize the controller
  * @hba: per adapter instance
  *
@@ -2834,18 +2854,9 @@ static int ufshcd_hba_enable(struct ufs_hba *hba)
         * development and testing of this driver. msleep can be changed to
         * mdelay and retry count can be reduced based on the controller.
         */
-       if (!ufshcd_is_hba_active(hba)) {
-
+       if (!ufshcd_is_hba_active(hba))
                /* change controller state to "reset state" */
-               ufshcd_hba_stop(hba);
-
-               /*
-                * This delay is based on the testing done with UFS host
-                * controller FPGA. The delay can be changed based on the
-                * host controller used.
-                */
-               msleep(5);
-       }
+               ufshcd_hba_stop(hba, true);
 
        /* UniPro link is disabled at this point */
        ufshcd_set_link_off(hba);
@@ -3898,7 +3909,7 @@ static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag)
        /* poll for max. 1 sec to clear door bell register by h/w */
        err = ufshcd_wait_for_register(hba,
                        REG_UTP_TASK_REQ_DOOR_BELL,
-                       mask, 0, 1000, 1000);
+                       mask, 0, 1000, 1000, true);
 out:
        return err;
 }
@@ -4180,7 +4191,7 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 
        /* Reset the host controller */
        spin_lock_irqsave(hba->host->host_lock, flags);
-       ufshcd_hba_stop(hba);
+       ufshcd_hba_stop(hba, false);
        spin_unlock_irqrestore(hba->host->host_lock, flags);
 
        err = ufshcd_hba_enable(hba);
@@ -5133,7 +5144,7 @@ static int ufshcd_link_state_transition(struct ufs_hba *hba,
                 * Change controller state to "reset state" which
                 * should also put the link in off/reset state
                 */
-               ufshcd_hba_stop(hba);
+               ufshcd_hba_stop(hba, true);
                /*
                 * TODO: Check if we need any delay to make sure that
                 * controller is reset
@@ -5609,7 +5620,7 @@ void ufshcd_remove(struct ufs_hba *hba)
        scsi_remove_host(hba->host);
        /* disable interrupts */
        ufshcd_disable_intr(hba, hba->intr_mask);
-       ufshcd_hba_stop(hba);
+       ufshcd_hba_stop(hba, true);
 
        scsi_host_put(hba->host);
 

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 9ae7f85..a6d3572 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -590,15 +590,9 @@ int ufshcd_alloc_host(struct device *, struct ufs_hba **);
 void ufshcd_dealloc_host(struct ufs_hba *);
 int ufshcd_init(struct ufs_hba * , void __iomem * , unsigned int);
 void ufshcd_remove(struct ufs_hba *);
-
-/**
- * ufshcd_hba_stop - Send controller to reset state
- * @hba: per adapter instance
- */
-static inline void ufshcd_hba_stop(struct ufs_hba *hba)
-{
-       ufshcd_writel(hba, CONTROLLER_DISABLE,  REG_CONTROLLER_ENABLE);
-}
+int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+                               u32 val, unsigned long interval_us,
+                               unsigned long timeout_ms, bool can_sleep);
 
 static inline void check_upiu_size(void)
 {