[PATCH v5 04/15] scsi: ufs: verify hba controller hce reg value

From: Yaniv Gardi
Date: Sun Feb 28 2016 - 08:33:18 EST


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.

Signed-off-by: Raviv Shvili <rshvili@xxxxxxxxxxxxxx>
Signed-off-by: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>

---
drivers/scsi/ufs/ufshcd.c | 53 ++++++++++++++++++++++++++++-------------------
drivers/scsi/ufs/ufshcd.h | 12 +++--------
2 files changed, 35 insertions(+), 30 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 3400ceb..80031e6 100644
--- 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
--- 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)
{
--
1.8.5.2

--
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