From fb03e07e9417c255fc0972af3b0d134f66b281e2 Mon Sep 17 00:00:00 2001
From: Daniel Kolesa <daniel@octaforge.org>
Date: Wed, 29 Apr 2020 17:02:36 +0200
Subject: drm/amd/display: work around fp code being emitted outside of
Git-commit: 59dfb0c64d3853d20dc84f4561f28d4f5a2ddc7d
Patch-mainline: v5.7-rc5
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
DC_FP_START/END
The dcn20_validate_bandwidth function would have code touching the
incorrect registers emitted outside of the boundaries of the
DC_FP_START/END macros, at least on ppc64le. Work around the
problem by wrapping the whole function instead.
Signed-off-by: Daniel Kolesa <daniel@octaforge.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org # 5.6.x
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
.../drm/amd/display/dc/dcn20/dcn20_resource.c | 31 ++++++++++++++-----
1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
index c3535bd3965b..e4348e3b6389 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
@@ -3068,25 +3068,32 @@ static bool dcn20_validate_bandwidth_internal(struct dc *dc, struct dc_state *co
return out;
}
-
-bool dcn20_validate_bandwidth(struct dc *dc, struct dc_state *context,
- bool fast_validate)
+/*
+ * This must be noinline to ensure anything that deals with FP registers
+ * is contained within this call; previously our compiling with hard-float
+ * would result in fp instructions being emitted outside of the boundaries
+ * of the DC_FP_START/END macros, which makes sense as the compiler has no
+ * idea about what is wrapped and what is not
+ *
+ * This is largely just a workaround to avoid breakage introduced with 5.6,
+ * ideally all fp-using code should be moved into its own file, only that
+ * should be compiled with hard-float, and all code exported from there
+ * should be strictly wrapped with DC_FP_START/END
+ */
+static noinline bool dcn20_validate_bandwidth_fp(struct dc *dc,
+ struct dc_state *context, bool fast_validate)
{
bool voltage_supported = false;
bool full_pstate_supported = false;
bool dummy_pstate_supported = false;
double p_state_latency_us;
- DC_FP_START();
p_state_latency_us = context->bw_ctx.dml.soc.dram_clock_change_latency_us;
context->bw_ctx.dml.soc.disable_dram_clock_change_vactive_support =
dc->debug.disable_dram_clock_change_vactive_support;
if (fast_validate) {
- voltage_supported = dcn20_validate_bandwidth_internal(dc, context, true);
-
- DC_FP_END();
- return voltage_supported;
+ return dcn20_validate_bandwidth_internal(dc, context, true);
}
// Best case, we support full UCLK switch latency
@@ -3115,7 +3122,15 @@ bool dcn20_validate_bandwidth(struct dc *dc, struct dc_state *context,
restore_dml_state:
context->bw_ctx.dml.soc.dram_clock_change_latency_us = p_state_latency_us;
+ return voltage_supported;
+}
+bool dcn20_validate_bandwidth(struct dc *dc, struct dc_state *context,
+ bool fast_validate)
+{
+ bool voltage_supported = false;
+ DC_FP_START();
+ voltage_supported = dcn20_validate_bandwidth_fp(dc, context, fast_validate);
DC_FP_END();
return voltage_supported;
}
--
2.28.0