[PATCH 5.17 001/219] drm/amd/display: Add pstate verification and recovery for DCN31

Greg Kroah-Hartman
2022-04-18T12:15:09Z

From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

commit e7031d8258f1b4d6d50e5e5b5d92ba16f66eb8b4 upstream.

[Why]
To debug when p-state is being blocked and avoid PMFW hangs when
it does occur.

[How]
Re-use the DCN10 hardware sequencer by adding a new interface for
verifying p-state high on the hubbub. The interface is mostly the
same as the DCN10 interface, but the bit definitions have changed for
the debug bus.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Eric Yang <Eric.Yang2@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hubbub.c | 1
drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c | 10 +-
drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hubbub.c | 1
drivers/gpu/drm/amd/display/dc/dcn301/dcn301_hubbub.c | 1
drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hubbub.c | 60 ++++++++++++++
drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c | 2
drivers/gpu/drm/amd/display/dc/inc/hw/dchubbub.h | 2
7 files changed, 73 insertions(+), 4 deletions(-)

--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hubbub.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hubbub.c
@@ -940,6 +940,7 @@ static const struct hubbub_funcs hubbub1
.program_watermarks = hubbub1_program_watermarks,
.is_allow_self_refresh_enabled = hubbub1_is_allow_self_refresh_enabled,
.allow_self_refresh_control = hubbub1_allow_self_refresh_control,
+ .verify_allow_pstate_change_high = hubbub1_verify_allow_pstate_change_high,
};

void hubbub1_construct(struct hubbub *hubbub,
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -1112,9 +1112,13 @@ static bool dcn10_hw_wa_force_recovery(s

void dcn10_verify_allow_pstate_change_high(struct dc *dc)
{
+ struct hubbub *hubbub = dc->res_pool->hubbub;
static bool should_log_hw_state; /* prevent hw state log by default */

- if (!hubbub1_verify_allow_pstate_change_high(dc->res_pool->hubbub)) {
+ if (!hubbub->funcs->verify_allow_pstate_change_high)
+ return;
+
+ if (!hubbub->funcs->verify_allow_pstate_change_high(hubbub)) {
int i = 0;

if (should_log_hw_state)
@@ -1123,8 +1127,8 @@ void dcn10_verify_allow_pstate_change_hi
TRACE_DC_PIPE_STATE(pipe_ctx, i, MAX_PIPES);
BREAK_TO_DEBUGGER();
if (dcn10_hw_wa_force_recovery(dc)) {
- /*check again*/
- if (!hubbub1_verify_allow_pstate_change_high(dc->res_pool->hubbub))
+ /*check again*/
+ if (!hubbub->funcs->verify_allow_pstate_change_high(hubbub))
BREAK_TO_DEBUGGER();
}
}
--- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hubbub.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hubbub.c
@@ -448,6 +448,7 @@ static const struct hubbub_funcs hubbub3
.program_watermarks = hubbub3_program_watermarks,
.allow_self_refresh_control = hubbub1_allow_self_refresh_control,
.is_allow_self_refresh_enabled = hubbub1_is_allow_self_refresh_enabled,
+ .verify_allow_pstate_change_high = hubbub1_verify_allow_pstate_change_high,
.force_wm_propagate_to_pipes = hubbub3_force_wm_propagate_to_pipes,
.force_pstate_change_control = hubbub3_force_pstate_change_control,
.init_watermarks = hubbub3_init_watermarks,
--- a/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_hubbub.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_hubbub.c
@@ -60,6 +60,7 @@ static const struct hubbub_funcs hubbub3
.program_watermarks = hubbub3_program_watermarks,
.allow_self_refresh_control = hubbub1_allow_self_refresh_control,
.is_allow_self_refresh_enabled = hubbub1_is_allow_self_refresh_enabled,
+ .verify_allow_pstate_change_high = hubbub1_verify_allow_pstate_change_high,
.force_wm_propagate_to_pipes = hubbub3_force_wm_propagate_to_pipes,
.force_pstate_change_control = hubbub3_force_pstate_change_control,
.hubbub_read_state = hubbub2_read_state,
--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hubbub.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hubbub.c
@@ -949,6 +949,65 @@ static void hubbub31_get_dchub_ref_freq(
}
}

+static bool hubbub31_verify_allow_pstate_change_high(struct hubbub *hubbub)
+{
+ struct dcn20_hubbub *hubbub2 = TO_DCN20_HUBBUB(hubbub);
+
+ /*
+ * Pstate latency is ~20us so if we wait over 40us and pstate allow
+ * still not asserted, we are probably stuck and going to hang
+ */
+ const unsigned int pstate_wait_timeout_us = 100;
+ const unsigned int pstate_wait_expected_timeout_us = 40;
+
+ static unsigned int max_sampled_pstate_wait_us; /* data collection */
+ static bool forced_pstate_allow; /* help with revert wa */
+
+ unsigned int debug_data = 0;
+ unsigned int i;
+
+ if (forced_pstate_allow) {
+ /* we hacked to force pstate allow to prevent hang last time
+ * we verify_allow_pstate_change_high. so disable force
+ * here so we can check status
+ */
+ REG_UPDATE_2(DCHUBBUB_ARB_DRAM_STATE_CNTL,
+ DCHUBBUB_ARB_ALLOW_PSTATE_CHANGE_FORCE_VALUE, 0,
+ DCHUBBUB_ARB_ALLOW_PSTATE_CHANGE_FORCE_ENABLE, 0);
+ forced_pstate_allow = false;
+ }
+
+ REG_WRITE(DCHUBBUB_TEST_DEBUG_INDEX, hubbub2->debug_test_index_pstate);
+
+ for (i = 0; i < pstate_wait_timeout_us; i++) {
+ debug_data = REG_READ(DCHUBBUB_TEST_DEBUG_DATA);
+
+ /* Debug bit is specific to ASIC. */
+ if (debug_data & (1 << 26)) {
+ if (i > pstate_wait_expected_timeout_us)
+ DC_LOG_WARNING("pstate took longer than expected ~%dus\n", i);
+ return true;
+ }
+ if (max_sampled_pstate_wait_us < i)
+ max_sampled_pstate_wait_us = i;
+
+ udelay(1);
+ }
+
+ /* force pstate allow to prevent system hang
+ * and break to debugger to investigate
+ */
+ REG_UPDATE_2(DCHUBBUB_ARB_DRAM_STATE_CNTL,
+ DCHUBBUB_ARB_ALLOW_PSTATE_CHANGE_FORCE_VALUE, 1,
+ DCHUBBUB_ARB_ALLOW_PSTATE_CHANGE_FORCE_ENABLE, 1);
+ forced_pstate_allow = true;
+
+ DC_LOG_WARNING("pstate TEST_DEBUG_DATA: 0x%X\n",
+ debug_data);
+
+ return false;
+}
+
static const struct hubbub_funcs hubbub31_funcs = {
.update_dchub = hubbub2_update_dchub,
.init_dchub_sys_ctx = hubbub31_init_dchub_sys_ctx,
@@ -961,6 +1020,7 @@ static const struct hubbub_funcs hubbub3
.program_watermarks = hubbub31_program_watermarks,
.allow_self_refresh_control = hubbub1_allow_self_refresh_control,
.is_allow_self_refresh_enabled = hubbub1_is_allow_self_refresh_enabled,
+ .verify_allow_pstate_change_high = hubbub31_verify_allow_pstate_change_high,
.program_det_size = dcn31_program_det_size,
.program_compbuf_size = dcn31_program_compbuf_size,
.init_crb = dcn31_init_crb,
--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
@@ -1011,7 +1011,7 @@ static const struct dc_debug_options deb
.max_downscale_src_width = 4096,/*upto true 4K*/
.disable_pplib_wm_range = false,
.scl_reset_length10 = true,
- .sanity_checks = false,
+ .sanity_checks = true,
.underflow_assert_delay_us = 0xFFFFFFFF,
.dwb_fi_phase = -1, // -1 = disable,
.dmub_command_table = true,
--- a/drivers/gpu/drm/amd/display/dc/inc/hw/dchubbub.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/hw/dchubbub.h
@@ -154,6 +154,8 @@ struct hubbub_funcs {
bool (*is_allow_self_refresh_enabled)(struct hubbub *hubbub);
void (*allow_self_refresh_control)(struct hubbub *hubbub, bool allow);

+ bool (*verify_allow_pstate_change_high)(struct hubbub *hubbub);
+
void (*apply_DEDCN21_147_wa)(struct hubbub *hubbub);

void (*force_wm_propagate_to_pipes)(struct hubbub *hubbub);