From: Mikhail Gavrilov <[email protected]>
[Why]
dcn32_validate_bandwidth() wraps dcn32_internal_validate_bw() with
DC_FP_START()/DC_FP_END(). In x86 non-RT, DC_FP_START takes fpregs_lock(),
which disables local softirqs.
The DML1 path through dcn32_enable_phantom_plane() calls kvzalloc() to
allocate ~335 KiB for dc_plane_state. This triggers the vmalloc path,
which calls BUG_ON(in_interrupt()) because it's invoked within the
FPU-enabled (softirq disabled) region, leading to a kernel crash.
[How]
Wrap the dc_state_create_phantom_plane() call with the
DC_RUN_WITH_PREEMPTION_ENABLED() macro to allow preemption during
this memory allocation.
Fixes: 235c67634230 ("drm/amd/display: add DCN32/321 specific files for Display
Core")
Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/4470
Reviewed-by: Aurabindo Pillai <[email protected]>
Signed-off-by: Mikhail Gavrilov <[email protected]>
Signed-off-by: James Lin <[email protected]>
---
.../drm/amd/display/dc/resource/dcn32/dcn32_resource.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c
b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c
index 28d21dd30106..1bdb4ffd2921 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c
@@ -92,9 +92,14 @@
#include "dml/dcn32/dcn32_fpu.h"
#include "dc_state_priv.h"
+#include "dc_fpu.h"
#include "dml2_0/dml2_wrapper.h"
+#if !defined(DC_RUN_WITH_PREEMPTION_ENABLED)
+#define DC_RUN_WITH_PREEMPTION_ENABLED(code) code
+#endif
+
#define DC_LOGGER_INIT(logger)
enum dcn32_clk_src_array_id {
@@ -1688,7 +1693,8 @@ static void dcn32_enable_phantom_plane(struct dc *dc,
if (curr_pipe->top_pipe && curr_pipe->top_pipe->plane_state ==
curr_pipe->plane_state)
phantom_plane = prev_phantom_plane;
else
- phantom_plane = dc_state_create_phantom_plane(dc,
context, curr_pipe->plane_state);
+ DC_RUN_WITH_PREEMPTION_ENABLED(phantom_plane =
+ dc_state_create_phantom_plane(dc, context,
curr_pipe->plane_state));
if (!phantom_plane)
continue;
--
2.43.0
