From: Mathias Nyman
> Sent: 10 October 2017 15:13
...
> [  428.409645] print_req_error: I/O error, dev sdb, sector 128
> [  428.426612] arm-smmu 2b500000.iommu: Unhandled context fault: fsr=0x8, 
> iova=0xff0b1000,
> fsynr=0x183, cb=0
> 
> a ring segment is 256 TRBS, each *16 bytes, that ring last TRB should be at 
> 0xff0b0ff0
> 
> If the adm-smmu iova 0xff0b1000 means something is poking that DMA address
> it's ring after that ring.

That could 'just' be the hardware doing a 'readahead' of the ring.
Somewhat annoying if it is doing that across page boundaries.

Although, in that case, the read values wouldn't be used because the
last TRB is a link.
So that shouldn't stop the USB transfer - just gives an annoying error message.
OTOH if the PCIe read completion ends up with an error status it might halt
the ring (or similar).

        David

N�����r��y����b�X��ǧv�^�)޺{.n�+����{������^n�r���z���h�����&���G���h�(�階�ݢj"���m������z�ޖ���f���h���~�m�

Reply via email to