From 174e4b9d0b2400e267bf96d1ee542fad7feaedb6 Mon Sep 17 00:00:00 2001
From: Drakulix <github@drakulix.de>
Date: Sun, 17 Sep 2017 22:54:36 +0200
Subject: [PATCH] Fix encoder detection

---
 src/backend/drm/mod.rs | 49 ++++++++++++++++--------------------------
 1 file changed, 18 insertions(+), 31 deletions(-)

diff --git a/src/backend/drm/mod.rs b/src/backend/drm/mod.rs
index f022815..a72134f 100644
--- a/src/backend/drm/mod.rs
+++ b/src/backend/drm/mod.rs
@@ -398,8 +398,6 @@ impl<H: DrmHandler + 'static> DrmDevice<H> {
     where
         I: Into<Vec<connector::Handle>>,
     {
-        use std::collections::hash_set::HashSet;
-
         for backend in self.backends.iter() {
             if let Some(backend) = backend.upgrade() {
                 if backend.borrow().is_crtc(crtc) {
@@ -410,36 +408,25 @@ impl<H: DrmHandler + 'static> DrmDevice<H> {
 
         // check if the given connectors and crtc match
         let connectors = connectors.into();
-        // get all encoders supported by this device
-        let mut set = self.context
-            .head()
-            .head()
-            .resource_handles()?
-            .encoders()
-            .iter()
-            .cloned()
-            .collect::<HashSet<encoder::Handle>>();
-        for connector in connectors.iter() {
-            let info = connector::Info::load_from_device(self.context.head().head(), *connector)?;
-            // then check for every connector which encoders it does support
-            let conn_set = info.encoders()
-                .iter()
-                .cloned()
-                .collect::<HashSet<encoder::Handle>>();
-            // and update the list of supported encoders for this combination
-            set = set.intersection(&conn_set)
-                .cloned()
-                .collect::<HashSet<encoder::Handle>>();
-        }
 
-        // check if there is any encoder left that can be connected to the crtc
-        let encoders: Vec<encoder::Info> = set.iter()
-            .map(|handle| {
-                encoder::Info::load_from_device(self.context.head().head(), *handle).map_err(DrmError::from)
-            })
-            .collect::<Result<Vec<encoder::Info>, DrmError>>()?;
-        if !encoders.iter().any(|enc| enc.supports_crtc(crtc)) {
-            return Err(DrmError::Crtc(CrtcError::NoSuitableEncoder));
+        // check if we have an encoder for every connector
+        for connector in connectors.iter() {
+            let con_info = connector::Info::load_from_device(self.context.head().head(), *connector)?;
+
+            // then check for every connector which encoders it does support
+            let encoders = con_info
+                .encoders()
+                .iter()
+                .map(|encoder| {
+                    encoder::Info::load_from_device(self.context.head().head(), *encoder)
+                        .map_err(DrmError::from)
+                })
+                .collect::<Result<Vec<encoder::Info>, DrmError>>()?;
+
+            // and if any encoder supports the selected crtc
+            if !encoders.iter().any(|encoder| encoder.supports_crtc(crtc)) {
+                return Err(DrmError::Crtc(CrtcError::NoSuitableEncoder));
+            }
         }
 
         // configuration is valid, the kernel will figure out the rest