HW vs SW frame 100 byte-compare: 100.00% exact match (1382400 /
1382400 bytes). 182 unique byte values, identical top-10
distribution.
Campaign actually completed at iter4 (kernel-agent#14 ext_sps
NULL init + kernel-agent#15 HEVC_SLICE_PARAMS registration).
iter5 'uniform Y=0x10/CbCr=0x80 black output' was a
mis-diagnosis — the bbb video first 3 frames ARE genuinely
all-black (intro fade-in). A 2-min SW-reference byte-compare
at iter5 close would have ended the campaign 10+ hours earlier.
iter6 (vb2 fence series, 3 versions, 6 WeChat recoveries):
off-path, but found a real upstream NULL deref at
dma_fence->context (offset 0x20) in dma_resv_add_fence —
file as kernel-agent#16 when UART confirms the register dump.
iter7 (DT dma-coherent on rkvdec): off-path AND falsified —
RK3588 rkvdec is NOT in ACE-Lite coherent domain. dma-coherent
causes HW timeouts. Reverted.
5 new/updated memories:
- feedback_compare_hw_against_sw_reference.md (the lesson)
- feedback_backup_before_module_replace.md
- feedback_sddm_autologin_disable.md
- feedback_no_session_termination_attempts.md (reinforced)
- reference_dmabuf_resv_blocker.md (overturned claim)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Markus Fritsche