I am trying to enable Coresight framework on STM32MP1 (ARMv7). More

specifically on CPU-wide kernel trace collection with perf.

I recently came across a decoding error from OpenCSD, which prevent the proper

trace decoding :

> perf report --stdio

    DCD_ETMV3_0018 : 0x0013 (OCSD_ERR_BAD_PACKET_SEQ) [Bad packet sequence];

TrcIdx=6969; CS ID=12; Bad Packet sequence.

    0x27438 [0x8]: failed to process type: 68 [Invalid argument]

> perf report --dump

[...]

        Idx:6961; ID:12;        P_HDR : Atom P-header.;

        Idx:6962; ID:12;        BRANCH_ADDRESS : Branch address.;

Addr=0x6C67BD40 ~[0x6C67BD40]; Exception=Jazelle;

        Idx:6967; ID:12;        P_HDR : Atom P-header.; EE

        Idx:6968; ID:12;        P_HDR : Atom P-header.;

        PKTP_ETMV3_0018 : 0x0013 (OCSD_ERR_BAD_PACKET_SEQ) [Bad packet

sequence]; TrcIdx=6969; CS ID=12; A-Sync ? : Unexpected byte in sequence

        Idx:6969; ID:12;        BAD_SEQUENCE : Invalid sequence for packet type.[A_SYNC]

        Idx:6970; ID:12;        P_HDR : Atom P-header.; EEEEEEEEEEEEEEE

       

What could explain this behavior ?

Thanks,

Raphaël