1 files changed, 32 insertions, 26 deletions

diff --git a/drivers/macintosh/via-cuda.c b/drivers/macintosh/via-cuda.c
index 76d21775fc35..741a93a3eb61 100644
--- a/drivers/macintosh/via-cuda.c
+++ b/drivers/macintosh/via-cuda.c
@@ -82,6 +82,7 @@ static unsigned char cuda_rbuf[16];
 static unsigned char *reply_ptr;
 static int reading_reply;
 static int data_index;
+static int cuda_irq;
 #ifdef CONFIG_PPC
 static struct device_node *vias;
 #endif
@@ -160,10 +161,8 @@ int __init find_via_cuda(void)
     /* Clear and enable interrupts, but only on PPC. On 68K it's done  */
     /* for us by the main VIA driver in arch/m68k/mac/via.c        */
 
-#ifndef CONFIG_MAC
     out_8(&via[IFR], 0x7f);     /* clear interrupts by writing 1s */
     out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
-#endif
 
     /* enable autopoll */
     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
@@ -181,24 +180,22 @@ int __init find_via_cuda(void)
 
 static int __init via_cuda_start(void)
 {
-    unsigned int irq;
-
     if (via == NULL)
         return -ENODEV;
 
 #ifdef CONFIG_MAC
-    irq = IRQ_MAC_ADB;
+    cuda_irq = IRQ_MAC_ADB;
 #else /* CONFIG_MAC */
-    irq = irq_of_parse_and_map(vias, 0);
-    if (irq == NO_IRQ) {
+    cuda_irq = irq_of_parse_and_map(vias, 0);
+    if (cuda_irq == NO_IRQ) {
         printk(KERN_ERR "via-cuda: can't map interrupts for %s\n",
                vias->full_name);
         return -ENODEV;
     }
-#endif /* CONFIG_MAP */
+#endif /* CONFIG_MAC */
 
-    if (request_irq(irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
-        printk(KERN_ERR "via-cuda: can't request irq %d\n", irq);
+    if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
+        printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
         return -EAGAIN;
     }
 
@@ -238,6 +235,7 @@ cuda_init(void)
         printk(KERN_ERR "cuda_init_via() failed\n");
         return -ENODEV;
     }
+    out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
 
     return via_cuda_start();
 #endif
@@ -263,15 +261,17 @@ cuda_init_via(void)
     out_8(&via[B], in_8(&via[B]) | TACK | TIP);                 /* negate them */
     out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT);    /* SR data in */
     (void)in_8(&via[SR]);                                               /* clear any left-over data */
-#ifndef CONFIG_MAC
+#ifdef CONFIG_PPC
     out_8(&via[IER], 0x7f);                                     /* disable interrupts from VIA */
     (void)in_8(&via[IER]);
+#else
+    out_8(&via[IER], SR_INT);                                   /* disable SR interrupt from VIA */
 #endif
 
     /* delay 4ms and then clear any pending interrupt */
     mdelay(4);
     (void)in_8(&via[SR]);
-    out_8(&via[IFR], in_8(&via[IFR]) & 0x7f);
+    out_8(&via[IFR], SR_INT);
 
     /* sync with the CUDA - assert TACK without TIP */
     out_8(&via[B], in_8(&via[B]) & ~TACK);
@@ -282,7 +282,7 @@ cuda_init_via(void)
     /* wait for the interrupt and then clear it */
     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
     (void)in_8(&via[SR]);
-    out_8(&via[IFR], in_8(&via[IFR]) & 0x7f);
+    out_8(&via[IFR], SR_INT);
 
     /* finish the sync by negating TACK */
     out_8(&via[B], in_8(&via[B]) | TACK);
@@ -291,7 +291,7 @@ cuda_init_via(void)
     WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)");
     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
     (void)in_8(&via[SR]);
-    out_8(&via[IFR], in_8(&via[IFR]) & 0x7f);
+    out_8(&via[IFR], SR_INT);
     out_8(&via[B], in_8(&via[B]) | TIP);        /* should be unnecessary */
 
     return 0;
@@ -428,16 +428,12 @@ cuda_start(void)
 void
 cuda_poll(void)
 {
-    unsigned long flags;
-
     /* cuda_interrupt only takes a normal lock, we disable
      * interrupts here to avoid re-entering and thus deadlocking.
-     * An option would be to disable only the IRQ source with
-     * disable_irq(), would that work on m68k ? --BenH
      */
-    local_irq_save(flags);
+    disable_irq(cuda_irq);
     cuda_interrupt(0, NULL);
-    local_irq_restore(flags);
+    enable_irq(cuda_irq);
 }
 
 static irqreturn_t
@@ -448,15 +444,25 @@ cuda_interrupt(int irq, void *arg)
     unsigned char ibuf[16];
     int ibuf_len = 0;
     int complete = 0;
-    unsigned char virq;
     
     spin_lock(&cuda_lock);
 
-    virq = in_8(&via[IFR]) & 0x7f;
-    out_8(&via[IFR], virq);   
-    if ((virq & SR_INT) == 0) {
-        spin_unlock(&cuda_lock);
-        return IRQ_NONE;
+    /* On powermacs, this handler is registered for the VIA IRQ. But it uses
+     * just the shift register IRQ -- other VIA interrupt sources are disabled.
+     * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
+     * we are polling, the shift register IRQ flag has already been cleared.
+     */
+
+#ifdef CONFIG_MAC
+    if (!arg)
+#endif
+    {
+        if ((in_8(&via[IFR]) & SR_INT) == 0) {
+            spin_unlock(&cuda_lock);
+            return IRQ_NONE;
+        } else {
+            out_8(&via[IFR], SR_INT);
+        }
     }
     
     status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);