ENGR00222157 MX6x-Fix bug in transitioning from low_bus to audio_bus mode.

Ensure that the transtion from low bus freq mode to
audio bus freq mode happens instantly. Don't schedule
the delayed work in this case else there will be a pause
in the audio playback.

Signed-off-by: Ranjani Vaidyanathan <ra5478@freescale.com>

diff --git a/arch/arm/mach-mx6/bus_freq.c b/arch/arm/mach-mx6/bus_freq.c
index 151b4ee27eb6caf4d852c7ac2eb08af6d975d25c..9d18423c85c5e7eaa086fcccb71e189b9c63275f 100644 (file)
--- a/arch/arm/mach-mx6/bus_freq.c
+++ b/arch/arm/mach-mx6/bus_freq.c
@@ -115,19 +115,8 @@ static struct clk *pll3_540;
 
 static struct delayed_work low_bus_freq_handler;
 
-static void reduce_bus_freq_handler(struct work_struct *work)
+void reduce_bus_freq(void)
 {
-       mutex_lock(&bus_freq_mutex);
-       if (low_bus_freq_mode || !low_freq_bus_used()) {
-               mutex_unlock(&bus_freq_mutex);
-               return;
-       }
-
-       if (audio_bus_freq_mode && lp_audio_freq) {
-               mutex_unlock(&bus_freq_mutex);
-               return;
-       }
-
        if (!cpu_is_mx6sl()) {
                if (cpu_is_mx6dl() &&
                        (clk_get_parent(axi_clk) != periph_clk))
@@ -196,6 +185,10 @@ static void reduce_bus_freq_handler(struct work_struct *work)
                                reg = __raw_writel(org_arm_podf, MXC_CCM_CACRR);
                                while (__raw_readl(MXC_CCM_CDHIPR))
                                        ;
+                               /* We have enabled PLL1 in the code below when
+                                 * ARM is from PLL1, so disable it here.
+                                 */
+                               clk_disable(pll1);
                        }
                        low_bus_freq_mode = 0;
                        audio_bus_freq_mode = 1;
@@ -230,6 +223,35 @@ static void reduce_bus_freq_handler(struct work_struct *work)
                spin_unlock_irqrestore(&freq_lock, flags);
        }
        high_bus_freq_mode = 0;
+
+}
+
+static void reduce_bus_freq_handler(struct work_struct *work)
+{
+       mutex_lock(&bus_freq_mutex);
+
+       if (!low_freq_bus_used()) {
+               mutex_unlock(&bus_freq_mutex);
+               return;
+       }
+       /* If we are already in audio bus freq mode,
+         * just return if lp_audio_freq is true.
+         */
+       if (audio_bus_freq_mode && lp_audio_freq) {
+               mutex_unlock(&bus_freq_mutex);
+               return;
+       }
+
+       /* If we dont want to transition from low bus to
+         * audio bus mode and are already in
+         *low bus mode, then return.
+         */
+       if (!lp_audio_freq && low_bus_freq_mode) {
+               mutex_unlock(&bus_freq_mutex);
+               return;
+       }
+       reduce_bus_freq();
+
        mutex_unlock(&bus_freq_mutex);
 }
 
@@ -245,10 +267,19 @@ int set_low_bus_freq(void)
        if (!bus_freq_scaling_initialized || !bus_freq_scaling_is_active)
                return 0;
 
-       /* Don't lower the frequency immediately. Instead scheduled a delayed
-         * work and drop the freq if the conditions still remain the same.
+       /* Check to see if we need to got from
+         * low bus freq mode to audio bus freq mode.
+         * If so, the change needs to be done immediately.
          */
-       schedule_delayed_work(&low_bus_freq_handler, usecs_to_jiffies(3000000));
+       if (lp_audio_freq && low_bus_freq_mode)
+               reduce_bus_freq();
+       else
+               /* Don't lower the frequency immediately. Instead
+                 * scheduled a delayed work and drop the freq if
+                 * the conditions still remain the same.
+                 */
+               schedule_delayed_work(&low_bus_freq_handler,
+                                       usecs_to_jiffies(3000000));
        return 0;
 }
 
@@ -395,13 +426,8 @@ void bus_freq_update(struct clk *clk, bool flag)
                                && (clk_get_usecount(clk) == 0)) {
                                if (!(clk->flags &
                                        (AHB_HIGH_SET_POINT | AHB_MED_SET_POINT))) {
-                                       if (low_freq_bus_used()) {
-                                               if ((clk->flags & AHB_AUDIO_SET_POINT) &
-                                                               !audio_bus_freq_mode)
-                                                       set_low_bus_freq();
-                                               else if (!low_bus_freq_mode)
-                                                       set_low_bus_freq();
-                                       }
+                                       if (low_freq_bus_used())
+                                               set_low_bus_freq();
                                } else {
                                        if ((clk->flags & AHB_MED_SET_POINT)
                                                && !med_bus_freq_mode) {