Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

[karo-tx-linux.git] / drivers / scsi / ufs / ufshcd.c

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2aa85e398f769e66f14838dbfee94759089c1fea..648a446758801ab6ff338d1dd9e5b5ab052df0da 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -183,6 +183,7 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
 static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on);
 static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba);
 static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
+static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba);
 static int ufshcd_host_reset_and_restore(struct ufs_hba *hba);
 static irqreturn_t ufshcd_intr(int irq, void *__hba);
 static int ufshcd_config_pwr_mode(struct ufs_hba *hba,
@@ -972,6 +973,8 @@ ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
 
        ufshcd_hold(hba, false);
        mutex_lock(&hba->uic_cmd_mutex);
+       ufshcd_add_delay_before_dme_cmd(hba);
+
        spin_lock_irqsave(hba->host->host_lock, flags);
        ret = __ufshcd_send_uic_cmd(hba, uic_cmd);
        spin_unlock_irqrestore(hba->host->host_lock, flags);
@@ -2058,6 +2061,37 @@ static int ufshcd_dme_link_startup(struct ufs_hba *hba)
        return ret;
 }
 
+static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba)
+{
+       #define MIN_DELAY_BEFORE_DME_CMDS_US    1000
+       unsigned long min_sleep_time_us;
+
+       if (!(hba->quirks & UFSHCD_QUIRK_DELAY_BEFORE_DME_CMDS))
+               return;
+
+       /*
+        * last_dme_cmd_tstamp will be 0 only for 1st call to
+        * this function
+        */
+       if (unlikely(!ktime_to_us(hba->last_dme_cmd_tstamp))) {
+               min_sleep_time_us = MIN_DELAY_BEFORE_DME_CMDS_US;
+       } else {
+               unsigned long delta =
+                       (unsigned long) ktime_to_us(
+                               ktime_sub(ktime_get(),
+                               hba->last_dme_cmd_tstamp));
+
+               if (delta < MIN_DELAY_BEFORE_DME_CMDS_US)
+                       min_sleep_time_us =
+                               MIN_DELAY_BEFORE_DME_CMDS_US - delta;
+               else
+                       return; /* no more delay required */
+       }
+
+       /* allow sleep for extra 50us if needed */
+       usleep_range(min_sleep_time_us, min_sleep_time_us + 50);
+}
+
 /**
  * ufshcd_dme_set_attr - UIC command for DME_SET, DME_PEER_SET
  * @hba: per adapter instance
@@ -2157,6 +2191,7 @@ static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba, struct uic_command *cmd)
 
        mutex_lock(&hba->uic_cmd_mutex);
        init_completion(&uic_async_done);
+       ufshcd_add_delay_before_dme_cmd(hba);
 
        spin_lock_irqsave(hba->host->host_lock, flags);
        hba->uic_async_done = &uic_async_done;