New SD mode P2 accessory board

evanh

Uh-oh, one of my seven SD cards doesn't like it ... getting a busy timeout following the first write ...

It's happy with the older v1.2 driver, so can't blame the card.

Normal CMD12,  Sysclock 350 MHz
 SD clock-divider set to sysclock/3 (116.6 MHz)
 CID decode:  ManID=9C   OEMID=SO  Name=USD00
  Ver=0.2   Serial=39A8FBFB   Date=2018-1
 cluster size = 8192 bytes

 Buffer = 2 kB,  Written 512 kB at 753 kB/s,  Verified,  Read 512 kB at 4558 kB/s
 Buffer = 2 kB,  Written 512 kB at 854 kB/s,  Verified,  Read 512 kB at 4558 kB/s
 Buffer = 2 kB,  Written 512 kB at 855 kB/s,  Verified,  Read 512 kB at 4558 kB/s

 Buffer = 4 kB,  Written 1024 kB at 1429 kB/s,  Verified,  Read 1024 kB at 8162 kB/s
 Buffer = 4 kB,  Written 1024 kB at 1678 kB/s,  Verified,  Read 1024 kB at 8162 kB/s
 Buffer = 4 kB,  Written 1024 kB at 1672 kB/s,  Verified,  Read 1024 kB at 8068 kB/s

 Buffer = 8 kB,  Written 2048 kB at 2949 kB/s,  Verified,  Read 2048 kB at 13420 kB/s
 Buffer = 8 kB,  Written 2048 kB at 2994 kB/s,  Verified,  Read 2048 kB at 13310 kB/s
 Buffer = 8 kB,  Written 2048 kB at 3331 kB/s,  Verified,  Read 2048 kB at 13423 kB/s

Wuerfel_21

IIRC while the write is ongoing, the result isn't guaranteed to be flushed, so you might need to plumb through the flushing from the FS layer.

evanh

Yup, my updated CTRL_SYNC ioctl() issues a CMD12 and then waits on card busy before returning. An fclose() on an open write generates this sync.

Rayman

@evanh That's pretty awesome speeds there!