From: Tianci Yin <tianci.yin@xxxxxxx>
[why]
Since the variable fpu_recursion_depth is per-CPU type, it has one copy
on each CPU, thread migration causes data consistency issue, then the
call trace shows up. And preemption disabling can't prevent migration.
[how]
Disable migration to ensure consistency of fpu_recursion_depth.
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
Signed-off-by: Tianci Yin <tianci.yin@xxxxxxx>
---
drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
index 1743ca0a3641..c42aa947c969 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
@@ -89,6 +89,7 @@ void dc_fpu_begin(const char *function_name, const int line)
if (*pcpu == 1) {
#if defined(CONFIG_X86)
+ migrate_disable();
kernel_fpu_begin();
#elif defined(CONFIG_PPC64)
if (cpu_has_feature(CPU_FTR_VSX_COMP)) {
@@ -129,6 +130,7 @@ void dc_fpu_end(const char *function_name, const int line)
if (*pcpu <= 0) {
#if defined(CONFIG_X86)
kernel_fpu_end();
+ migrate_enable();
#elif defined(CONFIG_PPC64)
if (cpu_has_feature(CPU_FTR_VSX_COMP)) {
disable_kernel_vsx();
--
2.34.1
