Commit 3ccd59f9 authored Jan 19, 2022 by Ivaylo Dimitrov Committed by Tomi Valkeinen Mar 28, 2022

drm: omapdrm: Do no allocate non-scanout GEMs through DMM/TILER

On devices with DMM, all allocations are done through either DMM or TILER.
DMM/TILER being a limited resource means that such allocations will start
to fail before actual free memory is exhausted. What is even worse is that
with time DMM/TILER space gets fragmented to the point that even if we have
enough free DMM/TILER space and free memory, allocation fails because there
is no big enough free block in DMM/TILER space.

Such failures can be easily observed with OMAP xorg DDX, for example -
starting few GUI applications (so buffers for their windows are allocated)
and then rotating landscape<->portrait while closing and opening new
windows soon results in allocation failures.

Fix that by mapping buffers through DMM/TILER only when really needed,
like, for scanout buffers.

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1642587791-13222-4-git-send-email-ivo.g.dimitrov.75@gmail.com

parent 1948d28d

drivers/gpu/drm/omapdrm/omap_gem.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -821,11 +821,13 @@ int omap_gem_pin(struct drm_gem_object obj, dma_addr_t dma_addr)
		if (ret)
		goto fail;

		if (omap_obj->flags & OMAP_BO_SCANOUT) {
		if (priv->has_dmm) {
		ret = omap_gem_pin_tiler(obj);
		if (ret)
		goto fail;
		}
		}
		} else {
		refcount_inc(&omap_obj->pin_cnt);
		}
		@@ -861,6 +863,8 @@ static void omap_gem_unpin_locked(struct drm_gem_object *obj)
		kfree(omap_obj->sgt);
		omap_obj->sgt = NULL;
		}
		if (!(omap_obj->flags & OMAP_BO_SCANOUT))
		return;
		if (priv->has_dmm) {
		ret = tiler_unpin(omap_obj->block);
		if (ret) {