On Wed, 23 May 2007 09:06:12 -0700
David Brownell <[EMAIL PROTECTED]> wrote:
> On Wednesday 23 May 2007, Ivan Kuten wrote:
> > board specific spi info :
> >
> > static struct spi_board_info chub_spi_devices[] = {
> > { /* DataFlash chip */
> > .modalias = "mtd_dataflash",
> > .chip_select = 0,
>
> Chipselect zero ... I've had one report that this driver has some issues
> on that chipselect. There seem to be two errata in conflict here:
>
> - One saying that when the controller manages chipselects, it
> does so incorrectly ... releasing it before it's told to do so,
> which prematurely terminates transactions. ("NPCSx rises if
> no data is to be transmitted")
>
> - Another saying that if it does *not* manage chipselects, then
> broken mode fault detect logic kicks in; this could be what
> you're seeing. ("Mode Fault does not allow more than one
> master on Chip Select 0")
Neither of these should cause any problems for the atmel_spi driver
since it manages chip selects using gpio and sets the MODFDIS bit in MR
to disable mode fault detection (I actually ran into both erratas myself
while developing the driver.)
And I did actually test the driver on STK1000 with an add-on board
connecting a dataflash chip to cs0 on the second SPI controller. But
this was on the AT32AP7000 which uses a newer version of the SPI
controller...
> I've CC'd the relevant folk from Atmel. Seems that maybe rm9200
> needs to have a special case whereby chipselect zero is managed
> by the hardware despite the first erratum. And maybe that because
> of that erratum, the DMA chaining needs to be made to work... else
> root-on-dataflash won't behave. (Or some other workaround.)
Hmm...I don't think I understand why DMA chaining will help in this
case. Could you explain a bit more?
> > eth0: Link now 100-FullDuplex
> > eth0: AT91 ethernet at 0xfefbc000 int=24 100-FullDuplex (00:12:34:56:78:9a)
> > eth0: National Semiconductor DP83848 PHY
> > NAND device: Manufacturer ID: 0xec, Chip ID: 0x76 (Samsung NAND 64MiB 3,3V
> > 8-bit)
> > Scanning device for bad blocks
> > Creating 1 MTD partitions on "NAND 64MiB 3,3V 8-bit":
> > 0x00000000-0x04000000 : "NAND Partition 1"
> > atmel_spi atmel_spi.0: Atmel SPI Controller at 0xfffe0000 (irq 13)
> >
> > Not booting further. Timer led is still blinking. Is atmel_spi usable?
> > I have working setup on 2.6.20 + corresponding patch from
> > maxim.org.za/at91_26.html + legacy "at91_dataflash" + legacy "at91_spi"
Is there any way you can get a dump of what the CPU is doing? Magic
SysRq, NMI, etc?
Håvard
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