[PATCH 5.14 327/849] drm/amd/display: dcn20_resource_construct reduce scope of FPU enabled

Greg Kroah-Hartman
2021-11-15T22:42:51Z

From: Anson Jacob <Anson.Jacob@amd.com>

[ Upstream commit bc39a69a2ac484e6575a958567c162ef56c9f278 ]

Limit when FPU is enabled to only functions that does FPU operations for
dcn20_resource_construct, which gets called during driver
initialization.

Enabling FPU operation disables preemption. Sleeping functions(mutex
(un)lock, memory allocation using GFP_KERNEL, etc.) should not be called
when preemption is disabled.

Fixes the following case caught by enabling
CONFIG_DEBUG_ATOMIC_SLEEP in kernel config
[ 1.338434] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:281
[ 1.347395] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 197, name: systemd-udevd
[ 1.356356] CPU: 7 PID: 197 Comm: systemd-udevd Not tainted 5.13.0+ #3
[ 1.356358] Hardware name: System manufacturer System Product Name/PRIME X570-PRO, BIOS 3405 02/01/2021
[ 1.356360] Call Trace:
[ 1.356361] dump_stack+0x6b/0x86
[ 1.356366] ___might_sleep.cold+0x87/0x98
[ 1.356370] __might_sleep+0x4b/0x80
[ 1.356372] mutex_lock+0x21/0x50
[ 1.356376] smu_get_uclk_dpm_states+0x3f/0x80 [amdgpu]
[ 1.356538] pp_nv_get_uclk_dpm_states+0x35/0x50 [amdgpu]
[ 1.356711] init_soc_bounding_box+0xf9/0x210 [amdgpu]
[ 1.356892] ? create_object+0x20d/0x340
[ 1.356897] ? dcn20_resource_construct+0x46f/0xd30 [amdgpu]
[ 1.357077] dcn20_resource_construct+0x4b1/0xd30 [amdgpu]
...

Tested on: 5700XT (NAVI10 0x1002:0x731F 0x1DA2:0xE410 0xC1)

Cc: Christian König <christian.koenig@amd.com>
Cc: Hersen Wu <hersenxs.wu@amd.com>
Cc: Anson Jacob <Anson.Jacob@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>

Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Acked-by: Agustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: Anson Jacob <Anson.Jacob@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../drm/amd/display/dc/dcn20/dcn20_resource.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 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 c78933a9d31c1..2c1d3d9b7cc14 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
@@ -3701,16 +3701,22 @@ static bool init_soc_bounding_box(struct dc *dc,
clock_limits_available = (status == PP_SMU_RESULT_OK);
}

- if (clock_limits_available && uclk_states_available && num_states)
+ if (clock_limits_available && uclk_states_available && num_states) {
+ DC_FP_START();
dcn20_update_bounding_box(dc, loaded_bb, &max_clocks, uclk_states, num_states);
- else if (clock_limits_available)
+ DC_FP_END();
+ } else if (clock_limits_available) {
+ DC_FP_START();
dcn20_cap_soc_clocks(loaded_bb, max_clocks);
+ DC_FP_END();
+ }
}

loaded_ip->max_num_otg = pool->base.res_cap->num_timing_generator;
loaded_ip->max_num_dpp = pool->base.pipe_count;
+ DC_FP_START();
dcn20_patch_bounding_box(dc, loaded_bb);
-
+ DC_FP_END();
return true;
}

@@ -3730,8 +3736,6 @@ static bool dcn20_resource_construct(
enum dml_project dml_project_version =
get_dml_project_version(ctx->asic_id.hw_internal_rev);

- DC_FP_START();
-
ctx->dc_bios->regs = &bios_regs;
pool->base.funcs = &dcn20_res_pool_funcs;

@@ -4080,12 +4084,10 @@ static bool dcn20_resource_construct(
pool->base.oem_device = NULL;
}

- DC_FP_END();
return true;

create_fail:

- DC_FP_END();
dcn20_resource_destruct(pool);

return false;
--
2.33.0