Le 04/08/2010 09:23, Albert ARIBAUD a écrit : > Le 04/08/2010 08:08, Prafulla Wadaskar a écrit :
>> 3. Instead of adding fixed 41/50 usec delay between the writes to >> Scontrol It would be good if you can check/poll some status bit >> associated with IDE controller, this will make mvsata driver rock >> solid on any platform. > > I've looked up the marvell kirkwood and orion docs for such a control > bit but found none. I'll look it up again, however it might help if > you can find someone inside Marvell who would, and could, provide the > info. I think I've found out how it works. I initially thought the DET field in SControl was a sort of reset line, and that writing a 1 would put the controller in continuous reset and writing a 0 to put it out of reset. But actually, DET is a command field : a write of 1 starts the reset sequence immediately: the DET field of the SStatus register will go from 0 to 3 (possibly passing through 1). Then you can set SControl's DET back to 0 so that you can use the port. Thus the init sequence becomes: write 3 to SControl's IPM and 1 to DET, read SStatus until its DET field is 3, write 0 to SControl's DET. However I'll keep a timeout value in the status read loop, because you can't expect SStatus to become 3: it could stay 0 if no drive is connected, for instance. If I did not keep a timeout, u-boot would freeze. :/ Amicalement, -- Albert. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
