rbcodec/dsp: restore configure loop in dsp_init() (FS#13386)

It seems removing this causes a crash on the Clip+ when playing
any file. Appears to be a timing-related issue as replacing the
loop with an mdelay() also fixes it. Needs further investigation
to identify the real cause of the problem, see FS#13386.

Change-Id: Ia93a2887a79b376de50563d6bb3bbc79cee11a1c

lib/rbcodec/dsp/dsp_core.c

@@ -535,6 +535,16 @@ void dsp_init(void)
         for (unsigned int j = 0; j < ARRAYLEN(dsp_init_fn); ++j)
             dsp_init_fn[j](dsp, i);
 
+        /*
+         * FIXME: This is a no-op and should not be needed, but it
+         *        appears there is a race condition here that causes
+         *        prefetch abort panics on the Clip+. See FS#13386.
+         *        Replacing the loop with mdelay(1) also suppresses
+         *        the crash.
+         */
+        for (unsigned int j = 0; j < DSP_NUM_PROC_STAGES; j++)
+            dsp_proc_database[j]->configure(NULL, dsp, DSP_INIT, i);
+
         dsp_configure(dsp, DSP_RESET, 0);
     }
 }

lib/rbcodec/dsp/dsp_core.h

@@ -32,6 +32,7 @@ enum dsp_ids
 
 enum dsp_settings
 {
+    DSP_INIT,
     DSP_RESET,
     DSP_SET_FREQUENCY,
     DSP_SET_SAMPLE_DEPTH,