[Trac #237] nandflash writes fail with OFW

[Zarro Boogs per Child]

#237: nandflash writes fail with OFW
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 Reporter:  cjb      |        Owner:  dwmw2  
     Type:  defect   |       Status:  new    
 Priority:  blocker  |    Milestone:  BTest-1
Component:  kernel   |   Resolution:         
 Keywords:           |  
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Changes (by wmb at firmworks.com):

  * owner:  wmb at firmworks.com => dwmw2
  * component:  distro => kernel

Comment:

 As David W. suspected, the problem is that the OFW driver was leaving the
 CaFe NAND controller in the "write protect" state.  The fix was trivial -
 just hit the soft-reset bit in the OFW driver close routine.  I've made
 that change.

 The Linux driver really should do the soft-reset too, in its
 initialization, thus ensuring a predictable init no matter what state the
 hardware is in.  This also has the advantage of making sure the DMA engine
 is in a clean state.

 The way to perform this reset is to first write 0x01, then 0x00 to the
 32-bit chip register at offset 0x3034.  You can just write that bit, no
 need to read/modify/write.

 I'm reassigning to David to get the change into Linux too.

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Ticket URL: <http://dev.laptop.org/ticket/237#comment:4>
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