Messages in this thread | | | Date | Mon, 18 Feb 2008 17:57:05 +0900 | From | "Magnus Damm" <> | Subject | Re: Current git very broken on the Dreamcast |
| |
Hi Adrian,
[fixed up Matsubara-sans address]
On Feb 17, 2008 4:48 AM, Adrian McMenamin <adrian@newgolddream.dyndns.info> wrote: > On Sat, 2008-02-16 at 18:38 +0000, Adrian McMenamin wrote: > > Will seek to bisect this, but I have just updated my sources to the > > latest git and it is not booting at all on the Dreamcast. > > > > With early printk on, I get nothing more than this before an instant > > reboot: > > > > [ 0.000000] Linux version 2.6.25-rc2-10953-g52065cd > > (adrian@bossclass) (gcc version 3.4.6) #511 PREEMPT Sat Feb 16 18:31:43 > > GMT 2008 > > [ 0.000000] console [sercon0] enabled > > [ 0.000000] Booting machvec: Sega Dreamcast > > > adrian@bossclass:~/gdrom-dev$ git bisect good > e036eaa681a17f71b64f6d9040fe605555623919 is first bad commit > commit e036eaa681a17f71b64f6d9040fe605555623919 > Author: Magnus Damm <magnus.damm@gmail.com> > Date: Thu Feb 14 13:52:43 2008 +0900 > > sh: use ctrl_in/out for on chip pci access > > This patch makes sure ctrl_inN/outN are used instead of inN/outN for > on chip > pci registers. Without this patch addresses may be adjusted using > the value > in generic_io_base. This patch makes it possible to set > generic_io_base and > have pci without reading and writing all over the place. > > Signed-off-by: Magnus Damm <damm@igel.co.jp> > Acked-by: Katsuya MATSUBARA <matsu@igel.co.jp> > Signed-off-by: Paul Mundt <lethal@linux-sh.org> > > :040000 040000 17a9f8181301e3a082d8a1a2fdef9b13ff1185e4 > 87e4a2e912be56b0d12e8a92db9489d6615c31f7 M arch
Thanks for tracking this down and sorry for breaking the dreamcast pci driver.
Most code for the dreamcast currently do direct register access using ctrl_inN/outN or readN/writeN. Only a few places use inN/outN and depend on the value of generic_io_base. Doing inN/outN is ok (but outdated, use ioreadN/iowriteN instead) in a portable pci/isa driver, but it doesn't make sense for any dreamcast specific code to rely on generic_io_base. For the dreamcast we already know the address at compile time so doing adjustment during runtime is just unnecessary overhead.
It is of course possible to revert the dreamcast-specific bits of the commit you pointed out, but I think the change for the dreamcast makes sense since it makes the code both faster and more uniform.
However, at this point it is broken. Sorry about that. I just looked through all upstream dreamcast-specific code I could find and irq.c is now the only file that does inN/outN. I've attached a patch that makes the irq code independent of generic_io_base. There is also another patch attached that adjusts the addresses of the pci register. Together they should solve the problem you are seeing. Please try them on top of 2.6.25-rc2.
With these patches io ports count from 0 -> 8k-1 instead of being a pointer. We currently rely on generic_io_base logic but that will be changed in the future.
Please let me know the results. Thank you.
/ magnus [unhandled content-type:application/octet-stream][unhandled content-type:application/octet-stream] | |