powerpc/powernv: Workaround OFW issues in prom_init.c

Open Firmware on OPAL machines seems to have issues if we close
stdin and/or we try to print things after calling "quiesce" so
we avoid doing both.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/prom_init.c

@@ -2969,9 +2969,11 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 	/*
 	 * in case stdin is USB and still active on IBM machines...
 	 * Unfortunately quiesce crashes on some powermacs if we have
-	 * closed stdin already (in particular the powerbook 101).
+	 * closed stdin already (in particular the powerbook 101). It
+	 * appears that the OPAL version of OFW doesn't like it either.
 	 */
-	if (RELOC(of_platform) != PLATFORM_POWERMAC)
+	if (RELOC(of_platform) != PLATFORM_POWERMAC &&
+	    RELOC(of_platform) != PLATFORM_OPAL)
 		prom_close_stdin();
 
 	/*
@@ -2987,8 +2989,12 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 	 * is common to us and kexec
 	 */
 	hdr = RELOC(dt_header_start);
-	prom_printf("returning from prom_init\n");
-	prom_debug("->dt_header_start=0x%x\n", hdr);
+
+	/* Don't print anything after quiesce under OPAL, it crashes OFW */
+	if (RELOC(of_platform) != PLATFORM_OPAL) {
+		prom_printf("returning from prom_init\n");
+		prom_debug("->dt_header_start=0x%x\n", hdr);
+	}
 
 #ifdef CONFIG_PPC32
 	reloc_got2(-offset);