[PATCH 5.4 71/74] drm/i915/sdvo: Filter out invalid outputs more sensibly

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>

commit 3e206b6aa6df7eed4297577e0cf8403169b800a2 upstream.

We try to filter out the corresponding xxx1 output
if the xxx0 output is not present. But the way that is
being done is pretty awkward. Make it less so.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20221026101134.20865-2-ville.syrjala@xxxxxxxxxxxxxxx
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
(cherry picked from commit cc1e66394daaa7e9f005e2487a84e34a39f9308b)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/i915/display/intel_sdvo.c |   27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

--- a/drivers/gpu/drm/i915/display/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/display/intel_sdvo.c
@@ -2869,16 +2869,33 @@ err:
 	return false;
 }
 
+static u16 intel_sdvo_filter_output_flags(u16 flags)
+{
+	flags &= SDVO_OUTPUT_MASK;
+
+	/* SDVO requires XXX1 function may not exist unless it has XXX0 function.*/
+	if (!(flags & SDVO_OUTPUT_TMDS0))
+		flags &= ~SDVO_OUTPUT_TMDS1;
+
+	if (!(flags & SDVO_OUTPUT_RGB0))
+		flags &= ~SDVO_OUTPUT_RGB1;
+
+	if (!(flags & SDVO_OUTPUT_LVDS0))
+		flags &= ~SDVO_OUTPUT_LVDS1;
+
+	return flags;
+}
+
 static bool
 intel_sdvo_output_setup(struct intel_sdvo *intel_sdvo, u16 flags)
 {
-	/* SDVO requires XXX1 function may not exist unless it has XXX0 function.*/
+	flags = intel_sdvo_filter_output_flags(flags);
 
 	if (flags & SDVO_OUTPUT_TMDS0)
 		if (!intel_sdvo_dvi_init(intel_sdvo, 0))
 			return false;
 
-	if ((flags & SDVO_TMDS_MASK) == SDVO_TMDS_MASK)
+	if (flags & SDVO_OUTPUT_TMDS1)
 		if (!intel_sdvo_dvi_init(intel_sdvo, 1))
 			return false;
 
@@ -2899,7 +2916,7 @@ intel_sdvo_output_setup(struct intel_sdv
 		if (!intel_sdvo_analog_init(intel_sdvo, 0))
 			return false;
 
-	if ((flags & SDVO_RGB_MASK) == SDVO_RGB_MASK)
+	if (flags & SDVO_OUTPUT_RGB1)
 		if (!intel_sdvo_analog_init(intel_sdvo, 1))
 			return false;
 
@@ -2907,11 +2924,11 @@ intel_sdvo_output_setup(struct intel_sdv
 		if (!intel_sdvo_lvds_init(intel_sdvo, 0))
 			return false;
 
-	if ((flags & SDVO_LVDS_MASK) == SDVO_LVDS_MASK)
+	if (flags & SDVO_OUTPUT_LVDS1)
 		if (!intel_sdvo_lvds_init(intel_sdvo, 1))
 			return false;
 
-	if ((flags & SDVO_OUTPUT_MASK) == 0) {
+	if (flags == 0) {
 		unsigned char bytes[2];
 
 		intel_sdvo->controlled_output = 0;