0x19C.50 WuReject PostT7Delay
- Nick Kuo
- BSOD Analysis
- 05 Mar, 2025
In dce110_edp_backlight_control, we request a wait of “post_T7_delay”. This wait was never satisfied before system BSOD 0x19C.
In our case, post_T7_delay was 100ms.
We could get the tick count when the thread had started waiting.
Since this is a mini kernel dump, we do not have KUSER_SHARED_DATA to immediately tell us the current tick count. But OS actually stores interrupt time in the header of dump file, and it is derived by tick count. For your dump file, it is the value of “0000005a`60dc49e1”
To convert this into tick count, divide it with “interrupts per tick” denominator. In our platform it is “0x2625a”
The current tick count is 0x25e84d.
We started waiting on 0x25e84a, and BSOD on 0x25e84d. It means that we have only waited for ~46.875ms until this point. The wait not satisfying is expected and is not due to schedule pressure causing no CPU time.
Given 0x19C.50 timeout is significantly longer, it is something else running before this wait, spent too much time, and caused the BSOD.