Patch "drm/cma-helper: Release non-coherent memory with dma_free_noncoherent()" has been added to the 5.15-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    drm/cma-helper: Release non-coherent memory with dma_free_noncoherent()

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-cma-helper-release-non-coherent-memory-with-dma_free_noncoherent.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.


>From 995f54ea962e03ec08b8bc6a4fe11a32b420edd3 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann at suse.de>
Date: Thu, 8 Jul 2021 19:51:46 +0200
Subject: drm/cma-helper: Release non-coherent memory with dma_free_noncoherent()

From: Thomas Zimmermann <tzimmermann at suse.de>

commit 995f54ea962e03ec08b8bc6a4fe11a32b420edd3 upstream.

The GEM CMA helpers allocate non-coherent (i.e., cached) backing storage
with dma_alloc_noncoherent(), but release it with dma_free_wc(). Fix this
with a call to dma_free_noncoherent(). Writecombining storage is still
released with dma_free_wc().

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Fixes: cf8ccbc72d61 ("drm: Add support for GEM buffers backed by non-coherent memory")
Acked-by: Paul Cercueil <paul at crapouillou.net>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Maxime Ripard <mripard at kernel.org>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: dri-devel at lists.freedesktop.org
Cc: <stable at vger.kernel.org> # v5.14+
Link: https://patchwork.freedesktop.org/patch/msgid/20210708175146.10618-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/gpu/drm/drm_gem_cma_helper.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -210,8 +210,13 @@ void drm_gem_cma_free_object(struct drm_
 			dma_buf_vunmap(gem_obj->import_attach->dmabuf, &map);
 		drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
 	} else if (cma_obj->vaddr) {
-		dma_free_wc(gem_obj->dev->dev, cma_obj->base.size,
-			    cma_obj->vaddr, cma_obj->paddr);
+		if (cma_obj->map_noncoherent)
+			dma_free_noncoherent(gem_obj->dev->dev, cma_obj->base.size,
+					     cma_obj->vaddr, cma_obj->paddr,
+					     DMA_TO_DEVICE);
+		else
+			dma_free_wc(gem_obj->dev->dev, cma_obj->base.size,
+				    cma_obj->vaddr, cma_obj->paddr);
 	}
 
 	drm_gem_object_release(gem_obj);


Patches currently in stable-queue which might be from tzimmermann at suse.de are

queue-5.15/drm-cma-helper-release-non-coherent-memory-with-dma_free_noncoherent.patch