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From c80a0ea33f0768fda307a524f4cf3fa9406e811e Mon Sep 17 00:00:00 2001
From: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Date: Mon, 2 Oct 2017 13:40:02 -0400
Subject: [PATCH 2536/4131] drm/amd/display: increase pstate wait timeout
For linux it takes longer than 40us so increasing it to
200us. Also added debug prints regarding the change
Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
---
.../drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
index db774b3..012ba7c 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -245,8 +245,13 @@ static void verify_allow_pstate_change_high(
{
/* pstate latency is ~20us so if we wait over 40us and pstate allow
* still not asserted, we are probably stuck and going to hang
+ *
+ * TODO: Figure out why it takes ~100us on linux
+ * pstate takes around ~100us on linux. Unknown currently as to
+ * why it takes that long on linux
*/
- static unsigned int pstate_wait_timeout_us = 40;
+ static unsigned int pstate_wait_timeout_us = 200;
+ static 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 */
static bool should_log_hw_state; /* prevent hw state log by default */
@@ -293,9 +298,15 @@ static void verify_allow_pstate_change_high(
for (i = 0; i < pstate_wait_timeout_us; i++) {
debug_data = REG_READ(DCHUBBUB_TEST_DEBUG_DATA);
- if (debug_data & (1 << 30))
- return;
+ if (debug_data & (1 << 30)) {
+
+ if (i > pstate_wait_expected_timeout_us)
+ dm_logger_write(hws->ctx->logger, LOG_WARNING,
+ "pstate took longer than expected ~%dus",
+ i);
+ return;
+ }
if (max_sampled_pstate_wait_us < i)
max_sampled_pstate_wait_us = i;
@@ -314,6 +325,9 @@ static void verify_allow_pstate_change_high(
dcn10_log_hw_state(hws->ctx->dc);
}
+ dm_logger_write(hws->ctx->logger, LOG_WARNING,
+ "pstate TEST_DEBUG_DATA: 0x%X",
+ debug_data);
BREAK_TO_DEBUGGER();
}
--
2.7.4
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