From 8cb0654431a9b49e0c4a960bc8314dfb9fbbd8b2 Mon Sep 17 00:00:00 2001
From: Fangzhi Zuo <Jerry.Zuo@amd.com>
Date: Thu, 16 Jun 2022 15:09:01 -0400
Subject: drm/amd/display: Fix dmub soft hang for PSR 1
Git-commit: 22676bc500c27d987a0b42cbe162aebf783f1c38
Patch-mainline: v6.0-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849
[Why]
Unexpected change of aux hw mapping causes dmub soft hang when
initiate aux transation at wrong aux channel.
ddc_channel stands for hw dp aux index which is from vbios,
but link_index is pure software concept for link count depending on which link
is probed first. They are not interchangeable.
dmub aux transaction could pass if happens eDP link_index gets
the same value as vbios ddc_channel, e.g., ddc_channel = 1, link_index = 1
if they gets different, e.g., ddc_channel = 2, link_index = 0, overwrite
ddc_channel with link_index will have wrong ddc channel being used for aux
transaction in dmub PSR, cause aux transaction soft hang.
[How]
ddc_channel mapping to each link is determined by vbios and further
parsed in dc. Such info. should not be touched in any kind, otherwise
the mapping is screwed up leading to aux transaction timeout.
Reviewed-by: Aurabindo Jayamohanan Pillai <Aurabindo.Pillai@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 810bc7059c6c..383185a3a398 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -8725,7 +8725,7 @@ static int amdgpu_dm_i2c_xfer(struct i2c_adapter *i2c_adap,
if (dc_submit_i2c(
ddc_service->ctx->dc,
- ddc_service->ddc_pin->hw_info.ddc_channel,
+ ddc_service->link->link_index,
&cmd))
result = num;
@@ -8761,8 +8761,6 @@ create_i2c(struct ddc_service *ddc_service,
snprintf(i2c->base.name, sizeof(i2c->base.name), "AMDGPU DM i2c hw bus %d", link_index);
i2c_set_adapdata(&i2c->base, i2c);
i2c->ddc_service = ddc_service;
- if (i2c->ddc_service->ddc_pin)
- i2c->ddc_service->ddc_pin->hw_info.ddc_channel = link_index;
return i2c;
}
--
2.38.1