1 files changed, 44 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.10/950-0683-drm-vc4-Simplify-a-bit-the-global-atomic_check.patch b/target/linux/bcm27xx/patches-5.10/950-0683-drm-vc4-Simplify-a-bit-the-global-atomic_check.patch
new file mode 100644
index 0000000000..3949941e46
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.10/950-0683-drm-vc4-Simplify-a-bit-the-global-atomic_check.patch
@@ -0,0 +1,44 @@
+From d88f88dfdce0c6911802cb9a0da0c43ade854183 Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime@cerno.tech>
+Date: Fri, 4 Dec 2020 16:11:34 +0100
+Subject: [PATCH] drm/vc4: Simplify a bit the global atomic_check
+
+When we can't allocate a new channel, we can simply return instead of
+having to handle both cases, and that simplifies a bit the code.
+
+Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
+Signed-off-by: Maxime Ripard <maxime@cerno.tech>
+---
+ drivers/gpu/drm/vc4/vc4_kms.c | 13 ++++++-------
+ 1 file changed, 6 insertions(+), 7 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_kms.c
++++ b/drivers/gpu/drm/vc4/vc4_kms.c
+@@ -793,6 +793,7 @@ static int vc4_pv_muxing_atomic_check(st
+ 			to_vc4_crtc_state(new_crtc_state);
+ 		struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+ 		unsigned int matching_channels;
++		unsigned int channel;
+ 
+ 		if (vc4->firmware_kms)
+ 			continue;
+@@ -836,14 +837,12 @@ static int vc4_pv_muxing_atomic_check(st
+ 		 * but it works so far.
+ 		 */
+ 		matching_channels = hvs_new_state->unassigned_channels & vc4_crtc->data->hvs_available_channels;
+-		if (matching_channels) {
+-			unsigned int channel = ffs(matching_channels) - 1;
+-
+-			new_vc4_crtc_state->assigned_channel = channel;
+-			hvs_new_state->unassigned_channels &= ~BIT(channel);
+-		} else {
++		if (!matching_channels)
+ 			return -EINVAL;
+-		}
++
++		channel = ffs(matching_channels) - 1;
++		new_vc4_crtc_state->assigned_channel = channel;
++		hvs_new_state->unassigned_channels &= ~BIT(channel);
+ 	}
+ 
+ 	return 0;