From 7791d1623ffb240cf8cf80fa5d3b492cc71d026c Mon Sep 17 00:00:00 2001
From: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Date: Wed, 5 Jan 2022 17:36:58 +0200
Subject: drm: omapdrm: Fix implicit dma_buf fencing
Git-commit: 36e195467ecca6a55fd1a9374d3109692f381fd7
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Currently omapdrm driver does not initialize dma_buf_export_info resv
member, which leads to a new dma_resv being allocated and attached to
the exported dma_buf. This leads to the issue that fences created on
dma_buf objects imported by other drivers are ignored by omapdrm, as only
fences in gem object resv are waited on. This leads to various issues like
displaying incomplete frames.

Fix that by initializing dma_buf resv to the resv of the gem object being
exported.

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1641397018-29872-1-git-send-email-ivo.g.dimitrov.75@gmail.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
index 57af3d97be77..ab3fc86e7256 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
@@ -93,6 +93,7 @@ struct dma_buf *omap_gem_prime_export(struct drm_gem_object *obj, int flags)
 	exp_info.size = omap_gem_mmap_size(obj);
 	exp_info.flags = flags;
 	exp_info.priv = obj;
+	exp_info.resv = obj->resv;
 
 	return drm_gem_dmabuf_export(obj->dev, &exp_info);
 }
-- 
2.38.1