From b335dfdd9eef81afd1358e282bbf05f34fded772 Mon Sep 17 00:00:00 2001
From: K900 <me@0upti.me>
Date: Tue, 6 Aug 2024 16:59:45 +0300
Subject: [PATCH] mesa: cherry-pick patch to fix broken video decoding on AMD
 iGPUs

---
 pkgs/development/libraries/mesa/default.nix         |  5 +++++
 pkgs/development/libraries/mesa/vcn-pagefault.patch | 10 ++++++++++
 2 files changed, 15 insertions(+)
 create mode 100644 pkgs/development/libraries/mesa/vcn-pagefault.patch

diff --git a/pkgs/development/libraries/mesa/default.nix b/pkgs/development/libraries/mesa/default.nix
index 5782ec9fbedf..6f3f7b45b569 100644
--- a/pkgs/development/libraries/mesa/default.nix
+++ b/pkgs/development/libraries/mesa/default.nix
@@ -138,6 +138,11 @@ in stdenv.mkDerivation {
 
   patches = [
     ./opencl.patch
+
+    # Manual backport of https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30510
+    # Fixes video corruption / crashes when decoding video on AMD iGPUs
+    # FIXME: remove when merged
+    ./vcn-pagefault.patch
   ];
 
   postPatch = ''
diff --git a/pkgs/development/libraries/mesa/vcn-pagefault.patch b/pkgs/development/libraries/mesa/vcn-pagefault.patch
new file mode 100644
index 000000000000..9b8c7b99c564
--- /dev/null
+++ b/pkgs/development/libraries/mesa/vcn-pagefault.patch
@@ -0,0 +1,10 @@
+--- a/src/gallium/drivers/radeonsi/radeon_vcn_dec.c
++++ b/src/gallium/drivers/radeonsi/radeon_vcn_dec.c
+@@ -1390,6 +1390,7 @@ static unsigned rvcn_dec_dynamic_dpb_t2_message(struct radeon_decoder *dec, rvcn
+                            dummy->dpb.res;
+                addr = dec->ws->buffer_get_virtual_address(dummy_res->buf);
+             }
++            dec->ws->cs_add_buffer(&dec->cs, d->dpb.res->buf, RADEON_USAGE_READWRITE | RADEON_USAGE_SYNCHRONIZED, RADEON_DOMAIN_VRAM);
+             dynamic_dpb_t2->dpbAddrLo[i] = addr;
+             dynamic_dpb_t2->dpbAddrHi[i] = addr >> 32;
+             ++dynamic_dpb_t2->dpbArraySize;