Mesa (master): radeonsi: use current context for DCC feedback-loop decompress, fixes Elemental
Marek Olšák
mareko at kemper.freedesktop.org
Wed Aug 17 12:19:51 UTC 2016
Module: Mesa
Branch: master
Commit: a6b5845a0d7547198037a2e5ea5c7d3f6f5f9f26
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=a6b5845a0d7547198037a2e5ea5c7d3f6f5f9f26
Author: Marek Olšák <marek.olsak at amd.com>
Date: Thu Aug 11 17:56:44 2016 +0200
radeonsi: use current context for DCC feedback-loop decompress, fixes Elemental
This is just a workaround. The problem is described in the code.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96541
v2: say that it's only between the current context and aux_context
Reviewed-by: Nicolai Hähnle <nicolai.haehnle at amd.com> (v1)
---
src/gallium/drivers/radeon/r600_pipe_common.h | 2 +-
src/gallium/drivers/radeon/r600_texture.c | 38 ++++++++++++++++++++++-----
src/gallium/drivers/radeonsi/si_blit.c | 12 +++------
src/gallium/drivers/radeonsi/si_descriptors.c | 2 +-
4 files changed, 38 insertions(+), 16 deletions(-)
diff --git a/src/gallium/drivers/radeon/r600_pipe_common.h b/src/gallium/drivers/radeon/r600_pipe_common.h
index e4002f9..5375044 100644
--- a/src/gallium/drivers/radeon/r600_pipe_common.h
+++ b/src/gallium/drivers/radeon/r600_pipe_common.h
@@ -771,7 +771,7 @@ void evergreen_do_fast_color_clear(struct r600_common_context *rctx,
struct r600_atom *fb_state,
unsigned *buffers, unsigned *dirty_cbufs,
const union pipe_color_union *color);
-bool r600_texture_disable_dcc(struct r600_common_screen *rscreen,
+bool r600_texture_disable_dcc(struct r600_common_context *rctx,
struct r600_texture *rtex);
void r600_init_screen_texture_functions(struct r600_common_screen *rscreen);
void r600_init_context_texture_functions(struct r600_common_context *rctx);
diff --git a/src/gallium/drivers/radeon/r600_texture.c b/src/gallium/drivers/radeon/r600_texture.c
index ddfa135..8c7bfa3 100644
--- a/src/gallium/drivers/radeon/r600_texture.c
+++ b/src/gallium/drivers/radeon/r600_texture.c
@@ -400,20 +400,44 @@ static bool r600_texture_discard_dcc(struct r600_common_screen *rscreen,
return true;
}
-bool r600_texture_disable_dcc(struct r600_common_screen *rscreen,
+/**
+ * Disable DCC for the texture. (first decompress, then discard metadata).
+ *
+ * There is unresolved multi-context synchronization issue between
+ * screen::aux_context and the current context. If applications do this with
+ * multiple contexts, it's already undefined behavior for them and we don't
+ * have to worry about that. The scenario is:
+ *
+ * If context 1 disables DCC and context 2 has queued commands that write
+ * to the texture via CB with DCC enabled, and the order of operations is
+ * as follows:
+ * context 2 queues draw calls rendering to the texture, but doesn't flush
+ * context 1 disables DCC and flushes
+ * context 1 & 2 reset descriptors and FB state
+ * context 2 flushes (new compressed tiles written by the draw calls)
+ * context 1 & 2 read garbage, because DCC is disabled, yet there are
+ * compressed tiled
+ *
+ * \param rctx the current context if you have one, or rscreen->aux_context
+ * if you don't.
+ */
+bool r600_texture_disable_dcc(struct r600_common_context *rctx,
struct r600_texture *rtex)
{
- struct r600_common_context *rctx =
- (struct r600_common_context *)rscreen->aux_context;
+ struct r600_common_screen *rscreen = rctx->screen;
if (!r600_can_disable_dcc(rtex))
return false;
+ if (&rctx->b == rscreen->aux_context)
+ pipe_mutex_lock(rscreen->aux_context_lock);
+
/* Decompress DCC. */
- pipe_mutex_lock(rscreen->aux_context_lock);
rctx->decompress_dcc(&rctx->b, rtex);
rctx->b.flush(&rctx->b, NULL, 0);
- pipe_mutex_unlock(rscreen->aux_context_lock);
+
+ if (&rctx->b == rscreen->aux_context)
+ pipe_mutex_unlock(rscreen->aux_context_lock);
return r600_texture_discard_dcc(rscreen, rtex);
}
@@ -492,6 +516,8 @@ static boolean r600_texture_get_handle(struct pipe_screen* screen,
unsigned usage)
{
struct r600_common_screen *rscreen = (struct r600_common_screen*)screen;
+ struct r600_common_context *aux_context =
+ (struct r600_common_context*)rscreen->aux_context;
struct r600_resource *res = (struct r600_resource*)resource;
struct r600_texture *rtex = (struct r600_texture*)resource;
struct radeon_bo_metadata metadata;
@@ -510,7 +536,7 @@ static boolean r600_texture_get_handle(struct pipe_screen* screen,
* access.
*/
if (usage & PIPE_HANDLE_USAGE_WRITE && rtex->dcc_offset) {
- if (r600_texture_disable_dcc(rscreen, rtex))
+ if (r600_texture_disable_dcc(aux_context, rtex))
update_metadata = true;
}
diff --git a/src/gallium/drivers/radeonsi/si_blit.c b/src/gallium/drivers/radeonsi/si_blit.c
index f4bff6b..3cfd011 100644
--- a/src/gallium/drivers/radeonsi/si_blit.c
+++ b/src/gallium/drivers/radeonsi/si_blit.c
@@ -557,10 +557,8 @@ static void si_check_render_feedback_textures(struct si_context *sctx,
render_feedback = true;
}
- if (render_feedback) {
- struct si_screen *screen = sctx->screen;
- r600_texture_disable_dcc(&screen->b, tex);
- }
+ if (render_feedback)
+ r600_texture_disable_dcc(&sctx->b, tex);
}
}
@@ -599,10 +597,8 @@ static void si_check_render_feedback_images(struct si_context *sctx,
render_feedback = true;
}
- if (render_feedback) {
- struct si_screen *screen = sctx->screen;
- r600_texture_disable_dcc(&screen->b, tex);
- }
+ if (render_feedback)
+ r600_texture_disable_dcc(&sctx->b, tex);
}
}
diff --git a/src/gallium/drivers/radeonsi/si_descriptors.c b/src/gallium/drivers/radeonsi/si_descriptors.c
index 7600671..1d04a9c 100644
--- a/src/gallium/drivers/radeonsi/si_descriptors.c
+++ b/src/gallium/drivers/radeonsi/si_descriptors.c
@@ -663,7 +663,7 @@ static void si_set_shader_image(struct si_context *ctx,
* The decompression is relatively cheap if the surface
* has been decompressed already.
*/
- if (r600_texture_disable_dcc(&screen->b, tex))
+ if (r600_texture_disable_dcc(&ctx->b, tex))
uses_dcc = false;
else
ctx->b.decompress_dcc(&ctx->b.b, tex);
More information about the mesa-commit
mailing list