macintosh/via-cuda: Don't rely on Cuda to end a transfer

Certain Cuda transfers have to be ended by the driver. According to Apple's open source Cuda driver, as found in mkLinux and XNU, this applies to any "open ended request such as PRAM read". This fixes an infinite polling loop in cuda_pram_read_byte(). Tested-by: Stan Johnson <[email protected]> Signed-off-by: Finn Thain <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
jangid · Jan 22, 2019 · 458c77f · 458c77f
1 parent aefcb74
commit 458c77f
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/drivers/macintosh/via-cuda.c b/drivers/macintosh/via-cuda.c
@@ -569,6 +569,7 @@ cuda_interrupt(int irq, void *arg)
     unsigned char ibuf[16];
     int ibuf_len = 0;
     int complete = 0;
+    bool full;
 
     spin_lock_irqsave(&cuda_lock, flags);
 
@@ -656,12 +657,13 @@ cuda_interrupt(int irq, void *arg)
 	break;
 
     case reading:
-	if (reading_reply ? ARRAY_FULL(current_req->reply, reply_ptr)
-	                  : ARRAY_FULL(cuda_rbuf, reply_ptr))
+	full = reading_reply ? ARRAY_FULL(current_req->reply, reply_ptr)
+	                     : ARRAY_FULL(cuda_rbuf, reply_ptr);
+	if (full)
 	    (void)in_8(&via[SR]);
 	else
 	    *reply_ptr++ = in_8(&via[SR]);
-	if (!TREQ_asserted(status)) {
+	if (!TREQ_asserted(status) || full) {
 	    if (mcu_is_egret)
 		assert_TACK();
 	    /* that's all folks */