openwrt/target/linux/bcm27xx/patches-5.10/950-0683-drm-vc4-Simplify-a-bit-the-global-atomic_check.patch

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;