Bug 207137 - AMDGPU incorrectly reports vddgfx voltage for R9 390
Summary: AMDGPU incorrectly reports vddgfx voltage for R9 390
Status: RESOLVED CODE_FIX
Alias: None
Product: Drivers
Classification: Unclassified
Component: Video(DRI - non Intel) (show other bugs)
Hardware: All Linux
: P1 low
Assignee: drivers_video-dri
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-04-06 14:44 UTC by sandy.8925
Modified: 2020-08-30 07:17 UTC (History)
2 users (show)

See Also:
Kernel Version: 5.8
Subsystem:
Regression: No
Bisected commit-id:

Attachments
dmesg output (138.99 KB, text/plain)
2020-04-06 17:22 UTC, sandy.8925 		Details
GPU VBIOS (64.00 KB, application/octet-stream)
2020-04-06 17:23 UTC, sandy.8925 		Details
Add an attachment (proposed patch, testcase, etc.)

Description sandy.8925 2020-04-06 14:44:00 UTC 
I'm using an R9 390 GPU.

vddgfx voltage is always reported as 1 Volt, regardless of load.

I debugged and found that in smu7_hwmgr.c , in funcion smu7_read_sensor(), the voltage is read from PLANE2_VID when a certain condition is true. This always results in a final value of 1 Volt.

When I changed the code to read only from PLANE1_VID, the correct voltage seems to be reported, and it changes under load, from ~900 mv to 1.3 V.

Please fix.
Comment 1 Alex Deucher 2020-04-06 15:07:47 UTC 
Can you attach a copy of your vbios and dmesg output?  You can dump a copy of your vbios using the following:
sudo cat /sys/kernel/debug/dri/0/amdgpu_vbios > /tmp/vbios.rom
Comment 2 sandy.8925 2020-04-06 17:22:47 UTC 
Created attachment 288233 [details]
dmesg output
Comment 3 sandy.8925 2020-04-06 17:23:23 UTC 
Created attachment 288235 [details]
GPU VBIOS
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