Re: Getting to the bottom of the Dreamcast DMA issue

[Paul M. <le...@li...>]

On Mon, Jul 16, 2007 at 09:40:03PM +0100, Adrian McMenamin wrote:
> On Mon, 2007-07-16 at 07:42 +0900, Paul Mundt wrote:
> > While there might be some problems in the channel management, you're
> > barking up the wrong tree here. This stuff worked fine before, and the
> > driver has undergone zero changes in terms of the DMA code since then.
> 
> OK, I've made sure that the modules are compiled and loaded in the right
> order, and built pvr2fb as a module - get this now:
> 
> Builds with correct number of channels:
> 
> [    0.036116] DMA: Registering DMA API.
> [    0.036203] DMA: Registering sh_dmac handler (4 channels).
> [    0.038616] DMA: Registering pvr2_dmac handler (1 channel).
> [    0.039326] DMA: Registering g2_dmac handler (4 channels).
> 
> But oopses on attempt to load module - don't know if this is a toolset
> problem or code:
> 
What happens if you have pvr2fb built in, does it simply reboot?

> / # modprobe pvr2fb
> [   74.814053] Fault in unaligned fixup: 0000 [#1]
> [   74.817984] Modules linked in: pvr2fb cfbcopyarea cfbimgblt
> cfbfillrect
> [   74.824808] 
> [   74.826344] Pid : 713, Comm:             modprobe
> [   74.831211] PC is at request_dma+0x2a/0x84
> [   74.835429] PC  : 8c10f96e SP  : 8c1fbea8 SR  : 400080f1 TEA :
> c0103be4    Not tainted

That's certainly not good. I suppose I'll have to plug in some dummy
DMACs and hash out where things went wrong. I'll take a look at it later
today.

Should also probably redo the dependencies so we're not able to
artificially change the number of channels (or better yet, let the
platform device take care of it).