Message ID | 20230125195401.4183544-8-jonathan.kim@amd.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | Upstream of kernel support for AMDGPU ISA debugging | expand |
Hi Jonathan, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on drm-tip/drm-tip] [also build test WARNING on linus/master v6.2-rc5] [cannot apply to drm-misc/drm-misc-next drm/drm-next drm-exynos/exynos-drm-next drm-intel/for-linux-next drm-intel/for-linux-next-fixes] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Jonathan-Kim/drm-amdkfd-add-debug-and-runtime-enable-interface/20230128-092952 base: git://anongit.freedesktop.org/drm/drm-tip drm-tip patch link: https://lore.kernel.org/r/20230125195401.4183544-8-jonathan.kim%40amd.com patch subject: [PATCH 07/32] drm/amdgpu: add gfx9.4.1 hw debug mode enable and disable calls config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20230129/202301291457.nbbgmBEG-lkp@intel.com/config) compiler: gcc-11 (Debian 11.3.0-8) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/3983dc0f35ebf17452f97c096b866e38c98318db git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Jonathan-Kim/drm-amdkfd-add-debug-and-runtime-enable-interface/20230128-092952 git checkout 3983dc0f35ebf17452f97c096b866e38c98318db # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 olddefconfig make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/amd/amdgpu/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@intel.com> All warnings (new ones prefixed by >>): drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c: In function 'suspend_resume_compute_scheduler': >> drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c:312:53: warning: implicit conversion from 'enum amd_hw_ip_block_type' to 'enum amd_ip_block_type' [-Wenum-conversion] 312 | return amdgpu_device_ip_wait_for_idle(adev, GC_HWIP); | ^~~~~~~ In file included from drivers/gpu/drm/amd/amdgpu/../display/dc/dc_types.h:36, from drivers/gpu/drm/amd/amdgpu/../display/dc/dm_services_types.h:30, from drivers/gpu/drm/amd/amdgpu/../include/dm_pp_interface.h:26, from drivers/gpu/drm/amd/amdgpu/amdgpu.h:64, from drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c:26: At top level: drivers/gpu/drm/amd/amdgpu/../display/dc/dc_hdmi_types.h:53:22: warning: 'dp_hdmi_dongle_signature_str' defined but not used [-Wunused-const-variable=] 53 | static const uint8_t dp_hdmi_dongle_signature_str[] = "DP-HDMI ADAPTOR"; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- >> drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c:343: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * restore_dbg_reisters is ignored here but is a general interface requirement drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c:369: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * keep_trap_enabled is ignored here but is a general interface requirement vim +312 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c 281 282 /* 283 * Helper used to suspend/resume gfx pipe for image post process work to set 284 * barrier behaviour. 285 */ 286 static int suspend_resume_compute_scheduler(struct amdgpu_device *adev, bool suspend) 287 { 288 int i, r = 0; 289 290 for (i = 0; i < adev->gfx.num_compute_rings; i++) { 291 struct amdgpu_ring *ring = &adev->gfx.compute_ring[i]; 292 293 if (!(ring && ring->sched.thread)) 294 continue; 295 296 /* stop secheduler and drain ring. */ 297 if (suspend) { 298 drm_sched_stop(&ring->sched, NULL); 299 r = amdgpu_fence_wait_empty(ring); 300 if (r) 301 goto out; 302 } else { 303 drm_sched_start(&ring->sched, false); 304 } 305 } 306 307 out: 308 /* return on resume or failure to drain rings. */ 309 if (!suspend || r) 310 return r; 311 > 312 return amdgpu_device_ip_wait_for_idle(adev, GC_HWIP); 313 } 314 315 static void set_barrier_auto_waitcnt(struct amdgpu_device *adev, bool enable_waitcnt) 316 { 317 uint32_t data; 318 319 WRITE_ONCE(adev->barrier_has_auto_waitcnt, enable_waitcnt); 320 321 if (!down_read_trylock(&adev->reset_domain->sem)) 322 return; 323 324 amdgpu_amdkfd_suspend(adev, false); 325 326 if (suspend_resume_compute_scheduler(adev, true)) 327 goto out; 328 329 data = RREG32(SOC15_REG_OFFSET(GC, 0, mmSQ_CONFIG)); 330 data = REG_SET_FIELD(data, SQ_CONFIG, DISABLE_BARRIER_WAITCNT, 331 enable_waitcnt ? 0 : 1); 332 WREG32(SOC15_REG_OFFSET(GC, 0, mmSQ_CONFIG), data); 333 334 out: 335 suspend_resume_compute_scheduler(adev, false); 336 337 amdgpu_amdkfd_resume(adev, false); 338 339 up_read(&adev->reset_domain->sem); 340 } 341 342 /** > 343 * restore_dbg_reisters is ignored here but is a general interface requirement 344 * for devices that support GFXOFF and where the RLC save/restore list 345 * does not support hw registers for debugging i.e. the driver has to manually 346 * initialize the debug mode registers after it has disabled GFX off during the 347 * debug session. 348 */ 349 static uint32_t kgd_arcturus_enable_debug_trap(struct amdgpu_device *adev, 350 bool restore_dbg_registers, 351 uint32_t vmid) 352 { 353 mutex_lock(&adev->grbm_idx_mutex); 354 355 kgd_gfx_v9_set_wave_launch_stall(adev, vmid, true); 356 357 set_barrier_auto_waitcnt(adev, true); 358 359 WREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_TRAP_MASK), 0); 360 361 kgd_gfx_v9_set_wave_launch_stall(adev, vmid, false); 362 363 mutex_unlock(&adev->grbm_idx_mutex); 364 365 return 0; 366 } 367
On 2023-01-25 14:53, Jonathan Kim wrote: > On GFX9.4.1, the implicit wait count instruction on s_barrier is > disabled by default in the driver during normal operation for > performance requirements. > > There is a hardware bug in GFX9.4.1 where if the implicit wait count > instruction after an s_barrier instruction is disabled, any wave that > hits an exception may step over the s_barrier when returning from the > trap handler with the barrier logic having no ability to be > aware of this, thereby causing other waves to wait at the barrier > indefinitely resulting in a shader hang. This bug has been corrected > for GFX9.4.2 and onward. > > Since the debugger subscribes to hardware exceptions, in order to avoid > this bug, the debugger must enable implicit wait count on s_barrier > for a debug session and disable it on detach. > > In order to change this setting in the in the device global SQ_CONFIG > register, the GFX pipeline must be idle. GFX9.4.1 as a compute device > will either dispatch work through the compute ring buffers used for > image post processing or through the hardware scheduler by the KFD. > > Have the KGD suspend and drain the compute ring buffer, then suspend the > hardware scheduler and block any future KFD process job requests before > changing the implicit wait count setting. Once set, resume all work. > > v2: remove flush on kfd suspend as that will be a general fix required > outside of this patch series. > comment on trap enable/disable ignored variables. > > Signed-off-by: Jonathan Kim <jonathan.kim@amd.com> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu.h | 3 + > .../drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c | 118 +++++++++++++++++- > drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 4 +- > 3 files changed, 122 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h > index 872450a3a164..3c03e34c194c 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h > @@ -1041,6 +1041,9 @@ struct amdgpu_device { > struct pci_saved_state *pci_state; > pci_channel_state_t pci_channel_state; > > + /* Track auto wait count on s_barrier settings */ > + bool barrier_has_auto_waitcnt; > + > struct amdgpu_reset_control *reset_cntl; > uint32_t ip_versions[MAX_HWIP][HWIP_MAX_INSTANCE]; > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c > index 4191af5a3f13..d5bb86ccd617 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c > @@ -26,6 +26,7 @@ > #include "amdgpu.h" > #include "amdgpu_amdkfd.h" > #include "amdgpu_amdkfd_arcturus.h" > +#include "amdgpu_reset.h" > #include "sdma0/sdma0_4_2_2_offset.h" > #include "sdma0/sdma0_4_2_2_sh_mask.h" > #include "sdma1/sdma1_4_2_2_offset.h" > @@ -48,6 +49,8 @@ > #include "amdgpu_amdkfd_gfx_v9.h" > #include "gfxhub_v1_0.h" > #include "mmhub_v9_4.h" > +#include "gc/gc_9_0_offset.h" > +#include "gc/gc_9_0_sh_mask.h" > > #define HQD_N_REGS 56 > #define DUMP_REG(addr) do { \ > @@ -276,6 +279,117 @@ int kgd_arcturus_hqd_sdma_destroy(struct amdgpu_device *adev, void *mqd, > return 0; > } > > +/* > + * Helper used to suspend/resume gfx pipe for image post process work to set > + * barrier behaviour. > + */ > +static int suspend_resume_compute_scheduler(struct amdgpu_device *adev, bool suspend) > +{ > + int i, r = 0; > + > + for (i = 0; i < adev->gfx.num_compute_rings; i++) { > + struct amdgpu_ring *ring = &adev->gfx.compute_ring[i]; > + > + if (!(ring && ring->sched.thread)) > + continue; > + > + /* stop secheduler and drain ring. */ > + if (suspend) { > + drm_sched_stop(&ring->sched, NULL); > + r = amdgpu_fence_wait_empty(ring); > + if (r) > + goto out; > + } else { > + drm_sched_start(&ring->sched, false); > + } > + } > + > +out: > + /* return on resume or failure to drain rings. */ > + if (!suspend || r) > + return r; > + > + return amdgpu_device_ip_wait_for_idle(adev, GC_HWIP); > +} > + > +static void set_barrier_auto_waitcnt(struct amdgpu_device *adev, bool enable_waitcnt) > +{ > + uint32_t data; > + > + WRITE_ONCE(adev->barrier_has_auto_waitcnt, enable_waitcnt); > + > + if (!down_read_trylock(&adev->reset_domain->sem)) > + return; > + > + amdgpu_amdkfd_suspend(adev, false); > + > + if (suspend_resume_compute_scheduler(adev, true)) > + goto out; > + > + data = RREG32(SOC15_REG_OFFSET(GC, 0, mmSQ_CONFIG)); > + data = REG_SET_FIELD(data, SQ_CONFIG, DISABLE_BARRIER_WAITCNT, > + enable_waitcnt ? 0 : 1); This could be ..., !enable_waitcnt); > + WREG32(SOC15_REG_OFFSET(GC, 0, mmSQ_CONFIG), data); > + > +out: > + suspend_resume_compute_scheduler(adev, false); > + > + amdgpu_amdkfd_resume(adev, false); > + > + up_read(&adev->reset_domain->sem); > +} > + > +/** Use /* here, since this is not a doc comment. > + * restore_dbg_reisters is ignored here but is a general interface requirement Typo: registers > + * for devices that support GFXOFF and where the RLC save/restore list > + * does not support hw registers for debugging i.e. the driver has to manually > + * initialize the debug mode registers after it has disabled GFX off during the > + * debug session. > + */ > +static uint32_t kgd_arcturus_enable_debug_trap(struct amdgpu_device *adev, > + bool restore_dbg_registers, > + uint32_t vmid) > +{ > + mutex_lock(&adev->grbm_idx_mutex); > + > + kgd_gfx_v9_set_wave_launch_stall(adev, vmid, true); > + > + set_barrier_auto_waitcnt(adev, true); > + > + WREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_TRAP_MASK), 0); > + > + kgd_gfx_v9_set_wave_launch_stall(adev, vmid, false); > + > + mutex_unlock(&adev->grbm_idx_mutex); > + > + return 0; > +} > + > +/** /* > + * keep_trap_enabled is ignored here but is a general interface requirement > + * for devices that support multi-process debugging where the performance > + * overhead from trap temporary setup needs to be bypassed when the debug > + * session has ended. > + */ > +static uint32_t kgd_arcturus_disable_debug_trap(struct amdgpu_device *adev, > + bool keep_trap_enabled, > + uint32_t vmid) > +{ > + > + mutex_lock(&adev->grbm_idx_mutex); > + > + kgd_gfx_v9_set_wave_launch_stall(adev, vmid, true); > + > + set_barrier_auto_waitcnt(adev, false); > + > + WREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_TRAP_MASK), 0); > + > + kgd_gfx_v9_set_wave_launch_stall(adev, vmid, false); > + > + mutex_unlock(&adev->grbm_idx_mutex); > + > + return 0; > +} > const struct kfd2kgd_calls arcturus_kfd2kgd = { > .program_sh_mem_settings = kgd_gfx_v9_program_sh_mem_settings, > .set_pasid_vmid_mapping = kgd_gfx_v9_set_pasid_vmid_mapping, > @@ -294,6 +408,8 @@ const struct kfd2kgd_calls arcturus_kfd2kgd = { > kgd_gfx_v9_get_atc_vmid_pasid_mapping_info, > .set_vm_context_page_table_base = > kgd_gfx_v9_set_vm_context_page_table_base, > + .enable_debug_trap = kgd_arcturus_enable_debug_trap, > + .disable_debug_trap = kgd_arcturus_disable_debug_trap, > .get_cu_occupancy = kgd_gfx_v9_get_cu_occupancy, > - .program_trap_handler_settings = kgd_gfx_v9_program_trap_handler_settings > + .program_trap_handler_settings = kgd_gfx_v9_program_trap_handler_settings, > }; > diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c > index 222fe87161b7..56d25a6f1da9 100644 > --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c > +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c > @@ -2376,8 +2376,8 @@ static void gfx_v9_0_init_sq_config(struct amdgpu_device *adev) > switch (adev->ip_versions[GC_HWIP][0]) { > case IP_VERSION(9, 4, 1): > tmp = RREG32_SOC15(GC, 0, mmSQ_CONFIG); > - tmp = REG_SET_FIELD(tmp, SQ_CONFIG, > - DISABLE_BARRIER_WAITCNT, 1); > + tmp = REG_SET_FIELD(tmp, SQ_CONFIG, DISABLE_BARRIER_WAITCNT, > + READ_ONCE(adev->barrier_has_auto_waitcnt) ? 0 : 1); This could be ..., !READ_ONCE(adev->barrier_has_auto_waitcnt)); With those nit-picks fixed, the patch is Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com> > WREG32_SOC15(GC, 0, mmSQ_CONFIG, tmp); > break; > default:
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 872450a3a164..3c03e34c194c 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -1041,6 +1041,9 @@ struct amdgpu_device { struct pci_saved_state *pci_state; pci_channel_state_t pci_channel_state; + /* Track auto wait count on s_barrier settings */ + bool barrier_has_auto_waitcnt; + struct amdgpu_reset_control *reset_cntl; uint32_t ip_versions[MAX_HWIP][HWIP_MAX_INSTANCE]; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c index 4191af5a3f13..d5bb86ccd617 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c @@ -26,6 +26,7 @@ #include "amdgpu.h" #include "amdgpu_amdkfd.h" #include "amdgpu_amdkfd_arcturus.h" +#include "amdgpu_reset.h" #include "sdma0/sdma0_4_2_2_offset.h" #include "sdma0/sdma0_4_2_2_sh_mask.h" #include "sdma1/sdma1_4_2_2_offset.h" @@ -48,6 +49,8 @@ #include "amdgpu_amdkfd_gfx_v9.h" #include "gfxhub_v1_0.h" #include "mmhub_v9_4.h" +#include "gc/gc_9_0_offset.h" +#include "gc/gc_9_0_sh_mask.h" #define HQD_N_REGS 56 #define DUMP_REG(addr) do { \ @@ -276,6 +279,117 @@ int kgd_arcturus_hqd_sdma_destroy(struct amdgpu_device *adev, void *mqd, return 0; } +/* + * Helper used to suspend/resume gfx pipe for image post process work to set + * barrier behaviour. + */ +static int suspend_resume_compute_scheduler(struct amdgpu_device *adev, bool suspend) +{ + int i, r = 0; + + for (i = 0; i < adev->gfx.num_compute_rings; i++) { + struct amdgpu_ring *ring = &adev->gfx.compute_ring[i]; + + if (!(ring && ring->sched.thread)) + continue; + + /* stop secheduler and drain ring. */ + if (suspend) { + drm_sched_stop(&ring->sched, NULL); + r = amdgpu_fence_wait_empty(ring); + if (r) + goto out; + } else { + drm_sched_start(&ring->sched, false); + } + } + +out: + /* return on resume or failure to drain rings. */ + if (!suspend || r) + return r; + + return amdgpu_device_ip_wait_for_idle(adev, GC_HWIP); +} + +static void set_barrier_auto_waitcnt(struct amdgpu_device *adev, bool enable_waitcnt) +{ + uint32_t data; + + WRITE_ONCE(adev->barrier_has_auto_waitcnt, enable_waitcnt); + + if (!down_read_trylock(&adev->reset_domain->sem)) + return; + + amdgpu_amdkfd_suspend(adev, false); + + if (suspend_resume_compute_scheduler(adev, true)) + goto out; + + data = RREG32(SOC15_REG_OFFSET(GC, 0, mmSQ_CONFIG)); + data = REG_SET_FIELD(data, SQ_CONFIG, DISABLE_BARRIER_WAITCNT, + enable_waitcnt ? 0 : 1); + WREG32(SOC15_REG_OFFSET(GC, 0, mmSQ_CONFIG), data); + +out: + suspend_resume_compute_scheduler(adev, false); + + amdgpu_amdkfd_resume(adev, false); + + up_read(&adev->reset_domain->sem); +} + +/** + * restore_dbg_reisters is ignored here but is a general interface requirement + * for devices that support GFXOFF and where the RLC save/restore list + * does not support hw registers for debugging i.e. the driver has to manually + * initialize the debug mode registers after it has disabled GFX off during the + * debug session. + */ +static uint32_t kgd_arcturus_enable_debug_trap(struct amdgpu_device *adev, + bool restore_dbg_registers, + uint32_t vmid) +{ + mutex_lock(&adev->grbm_idx_mutex); + + kgd_gfx_v9_set_wave_launch_stall(adev, vmid, true); + + set_barrier_auto_waitcnt(adev, true); + + WREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_TRAP_MASK), 0); + + kgd_gfx_v9_set_wave_launch_stall(adev, vmid, false); + + mutex_unlock(&adev->grbm_idx_mutex); + + return 0; +} + +/** + * keep_trap_enabled is ignored here but is a general interface requirement + * for devices that support multi-process debugging where the performance + * overhead from trap temporary setup needs to be bypassed when the debug + * session has ended. + */ +static uint32_t kgd_arcturus_disable_debug_trap(struct amdgpu_device *adev, + bool keep_trap_enabled, + uint32_t vmid) +{ + + mutex_lock(&adev->grbm_idx_mutex); + + kgd_gfx_v9_set_wave_launch_stall(adev, vmid, true); + + set_barrier_auto_waitcnt(adev, false); + + WREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_TRAP_MASK), 0); + + kgd_gfx_v9_set_wave_launch_stall(adev, vmid, false); + + mutex_unlock(&adev->grbm_idx_mutex); + + return 0; +} const struct kfd2kgd_calls arcturus_kfd2kgd = { .program_sh_mem_settings = kgd_gfx_v9_program_sh_mem_settings, .set_pasid_vmid_mapping = kgd_gfx_v9_set_pasid_vmid_mapping, @@ -294,6 +408,8 @@ const struct kfd2kgd_calls arcturus_kfd2kgd = { kgd_gfx_v9_get_atc_vmid_pasid_mapping_info, .set_vm_context_page_table_base = kgd_gfx_v9_set_vm_context_page_table_base, + .enable_debug_trap = kgd_arcturus_enable_debug_trap, + .disable_debug_trap = kgd_arcturus_disable_debug_trap, .get_cu_occupancy = kgd_gfx_v9_get_cu_occupancy, - .program_trap_handler_settings = kgd_gfx_v9_program_trap_handler_settings + .program_trap_handler_settings = kgd_gfx_v9_program_trap_handler_settings, }; diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c index 222fe87161b7..56d25a6f1da9 100644 --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c @@ -2376,8 +2376,8 @@ static void gfx_v9_0_init_sq_config(struct amdgpu_device *adev) switch (adev->ip_versions[GC_HWIP][0]) { case IP_VERSION(9, 4, 1): tmp = RREG32_SOC15(GC, 0, mmSQ_CONFIG); - tmp = REG_SET_FIELD(tmp, SQ_CONFIG, - DISABLE_BARRIER_WAITCNT, 1); + tmp = REG_SET_FIELD(tmp, SQ_CONFIG, DISABLE_BARRIER_WAITCNT, + READ_ONCE(adev->barrier_has_auto_waitcnt) ? 0 : 1); WREG32_SOC15(GC, 0, mmSQ_CONFIG, tmp); break; default:
On GFX9.4.1, the implicit wait count instruction on s_barrier is disabled by default in the driver during normal operation for performance requirements. There is a hardware bug in GFX9.4.1 where if the implicit wait count instruction after an s_barrier instruction is disabled, any wave that hits an exception may step over the s_barrier when returning from the trap handler with the barrier logic having no ability to be aware of this, thereby causing other waves to wait at the barrier indefinitely resulting in a shader hang. This bug has been corrected for GFX9.4.2 and onward. Since the debugger subscribes to hardware exceptions, in order to avoid this bug, the debugger must enable implicit wait count on s_barrier for a debug session and disable it on detach. In order to change this setting in the in the device global SQ_CONFIG register, the GFX pipeline must be idle. GFX9.4.1 as a compute device will either dispatch work through the compute ring buffers used for image post processing or through the hardware scheduler by the KFD. Have the KGD suspend and drain the compute ring buffer, then suspend the hardware scheduler and block any future KFD process job requests before changing the implicit wait count setting. Once set, resume all work. v2: remove flush on kfd suspend as that will be a general fix required outside of this patch series. comment on trap enable/disable ignored variables. Signed-off-by: Jonathan Kim <jonathan.kim@amd.com> --- drivers/gpu/drm/amd/amdgpu/amdgpu.h | 3 + .../drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c | 118 +++++++++++++++++- drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 4 +- 3 files changed, 122 insertions(+), 3 deletions(-)