as3525: as revealed by r26311, it seems DMAC interrupt can't be masked

Even if we disable it in VIC_INT_EN_CLEAR, it still fires an interrupt
by running the default isr.
Locking requires disabling interrupts completely.
I'm not sure if DMAC is the only interrupt affected or if we can't rely
on VIC_INT_EN_CLEAR to mask interrupts.
If it's the latter, we will need to have special locking scheme for
INT_AUDIO.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26316 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 7 insertions, 4 deletions

diff --git a/firmware/target/arm/as3525/pcm-as3525.c b/firmware/target/arm/as3525/pcm-as3525.c
index 01d228f784..5a403bad83 100644
--- a/firmware/target/arm/as3525/pcm-as3525.c
+++ b/firmware/target/arm/as3525/pcm-as3525.c
@@ -40,18 +40,20 @@ static size_t      dma_size;   /* in 4*32 bits */
 static void dma_callback(void);
 static int locked = 0;
 
+static int play_irq_state;
+
 /* Mask the DMA interrupt */
 void pcm_play_lock(void)
 {
     if(++locked == 1)
-        VIC_INT_EN_CLEAR = INTERRUPT_DMAC;
+        play_irq_state = disable_irq_save();
 }
 
 /* Unmask the DMA interrupt if enabled */
 void pcm_play_unlock(void)
 {
     if(--locked == 0)
-        VIC_INT_ENABLE = INTERRUPT_DMAC;
+        restore_irq(play_irq_state);
 }
 
 static void play_start_pcm(void)
@@ -198,18 +200,19 @@ static void rec_dma_callback(void);
 static int16_t *mono_samples;
 #endif
 
+static int rec_irq_state;
 
 void pcm_rec_lock(void)
 {
     if(++rec_locked == 1)
-        VIC_INT_EN_CLEAR = INTERRUPT_DMAC;
+        rec_irq_state = disable_irq_save();
 }
 
 
 void pcm_rec_unlock(void)
 {
     if(--rec_locked == 0)
-        VIC_INT_ENABLE = INTERRUPT_DMAC;
+        restore_irq(rec_irq_state);
 }