> -----Original Message----- > From: Albert ARIBAUD [mailto:albert.arib...@free.fr] > Sent: Thursday, August 05, 2010 1:34 AM > To: Albert ARIBAUD > Cc: Prafulla Wadaskar; u-boot@lists.denx.de; Prabhanjan > Sarnaik; Ashish Karkare; tanmay.upadh...@einfochips.com > Subject: Re: [PATCH V5 4/4] edminiv2: add mvsata_ide and > cmd_ide support > > 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. :/
Hi Albert Good findings.... This would be great improvement with right approach. Regards.. Prafulla . . _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
