drm/i915: Init important ns2501 registers

In my earlier rewrite I missed a few important registers. Thomas Richter
noticed that they're needed to make his machine resume correctly.

Looks like IEGD does a one time init of these three registers. We don't
have a good one time init place in the ns2501 driver, so let's just
stick them into the .mode_set() hook and see if that helps things along.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Thomas Richter <richter@rus.uni-stuttgart.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/dvo_ns2501.c

@@ -342,6 +342,12 @@ static const struct ns2501_reg regs_1024x768[][86] = {
 	},
 };
 
+static const struct ns2501_reg regs_init[] = {
+	[0] = { .offset = 0x35, .value = 0xff, },
+	[1] = { .offset = 0x34, .value = 0x00, },
+	[2] = { .offset = 0x08, .value = 0x30, },
+};
+
 struct ns2501_priv {
 	bool quiet;
 	const struct ns2501_reg *regs;
@@ -544,6 +550,10 @@ static void ns2501_mode_set(struct intel_dvo_device *dvo,
 	else
 		return;
 
+	/* Hopefully doing it every time won't hurt... */
+	for (i = 0; i < ARRAY_SIZE(regs_init); i++)
+		ns2501_writeb(dvo, regs_init[i].offset, regs_init[i].value);
+
 	ns->regs = regs_1024x768[mode_idx];
 
 	for (i = 0; i < 84; i++)