i915: revert some checks added by commit 32aad86f

This fixes blur-like screen corruption on the following card:

VGA compatible controller [0300]: Intel Corporation 82G33/G31 Express
Integrated Graphics Controller [8086:29c2] (rev 10)

intel_sdvo_mode_set() should not return prematurely just because some
features are not supported.

https://bugzilla.kernel.org/show_bug.cgi?id=17151

Signed-off-by: Pavel Roskin <proski@gnu.org>
Reported-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[ickle: Relax a couple more checks for failing LVDS modesetting]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/intel_sdvo.c

@@ -1061,8 +1061,9 @@ static bool intel_sdvo_mode_fixup(struct drm_encoder *encoder,
 		if (!intel_sdvo_set_output_timings_from_mode(intel_sdvo, mode))
 			return false;
 
-		if (!intel_sdvo_set_input_timings_for_mode(intel_sdvo, mode, adjusted_mode))
-			return false;
+		(void) intel_sdvo_set_input_timings_for_mode(intel_sdvo,
+							     mode,
+							     adjusted_mode);
 	} else if (intel_sdvo->is_lvds) {
 		drm_mode_set_crtcinfo(intel_sdvo->sdvo_lvds_fixed_mode, 0);
 
@@ -1070,8 +1071,9 @@ static bool intel_sdvo_mode_fixup(struct drm_encoder *encoder,
 							    intel_sdvo->sdvo_lvds_fixed_mode))
 			return false;
 
-		if (!intel_sdvo_set_input_timings_for_mode(intel_sdvo, mode, adjusted_mode))
-			return false;
+		(void) intel_sdvo_set_input_timings_for_mode(intel_sdvo,
+							     mode,
+							     adjusted_mode);
 	}
 
 	/* Make the CRTC code factor in the SDVO pixel multiplier.  The
@@ -1108,10 +1110,9 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 	in_out.in0 = intel_sdvo->attached_output;
 	in_out.in1 = 0;
 
-	if (!intel_sdvo_set_value(intel_sdvo,
-				  SDVO_CMD_SET_IN_OUT_MAP,
-				  &in_out, sizeof(in_out)))
-		return;
+	intel_sdvo_set_value(intel_sdvo,
+			     SDVO_CMD_SET_IN_OUT_MAP,
+			     &in_out, sizeof(in_out));
 
 	if (intel_sdvo->is_hdmi) {
 		if (!intel_sdvo_set_avi_infoframe(intel_sdvo, mode))
@@ -1122,11 +1123,9 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 
 	/* We have tried to get input timing in mode_fixup, and filled into
 	   adjusted_mode */
-	if (intel_sdvo->is_tv || intel_sdvo->is_lvds) {
-		intel_sdvo_get_dtd_from_mode(&input_dtd, adjusted_mode);
+	intel_sdvo_get_dtd_from_mode(&input_dtd, adjusted_mode);
+	if (intel_sdvo->is_tv || intel_sdvo->is_lvds)
 		input_dtd.part2.sdvo_flags = intel_sdvo->sdvo_flags;
-	} else
-		intel_sdvo_get_dtd_from_mode(&input_dtd, mode);
 
 	/* If it's a TV, we already set the output timing in mode_fixup.
 	 * Otherwise, the output timing is equal to the input timing.
@@ -1137,8 +1136,7 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 						  intel_sdvo->attached_output))
 			return;
 
-		if (!intel_sdvo_set_output_timing(intel_sdvo, &input_dtd))
-			return;
+		(void) intel_sdvo_set_output_timing(intel_sdvo, &input_dtd);
 	}
 
 	/* Set the input timing to the screen. Assume always input 0. */
@@ -1165,8 +1163,7 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 		intel_sdvo_set_input_timing(encoder, &input_dtd);
 	}
 #else
-	if (!intel_sdvo_set_input_timing(intel_sdvo, &input_dtd))
-		return;
+	(void) intel_sdvo_set_input_timing(intel_sdvo, &input_dtd);
 #endif
 
 	sdvo_pixel_multiply = intel_sdvo_get_pixel_multiplier(mode);