ppc fails to attach to puc on 9.1-STABLE, 7.4-STABLE works

[John Baldwin]

On Tuesday, January 15, 2013 10:44:33 am Andre Albsmeier wrote:
> On Mon, 14-Jan-2013 at 21:02:58 +0100, John Baldwin wrote:
> > On Thursday, January 10, 2013 2:40:52 am Andre Albsmeier wrote:
> > > [Retrying here, maybe anyone can help...}
> > > 
> > > I want my printer port back on 9.1 ;-(
> > > 
> > > I have this card:
> > > 
> > > puc0 at pci0:4:1:0:        class=0x078000 card=0x00121000 chip=0x98359710 
> > rev=0x01 hdr=0x00
> > >     vendor     = 'NetMos Technology'
> > >     device     = 'PCI 9835 Multi-I/O Controller'
> > >     class      = simple comms
> > > 
> > > It attached and worked under 7.4-STABLE (as long as I disabled
> > > the interrupt using hint.ppc.0.irq=""):
> > > 
> > > puc0: <NetMos NM9835 Dual UART and 1284 Printer port> port 
> > 0xdf00-0xdf07,0xde00-0xde07,0xdd00-0xdd07
> > > ,0xdc00-0xdc07,0xdb00-0xdb07,0xda00-0xda0f irq 17 at device 1.0 on pci4
> > > puc0: [FILTER]
> > > uart0: <Non-standard ns8250 class UART with FIFOs> on puc0
> > > uart0: [FILTER]
> > > uart1: <Non-standard ns8250 class UART with FIFOs> on puc0
> > > uart1: [FILTER]
> > > ppc0: <Parallel port> on puc0
> > > ppc0: Generic chipset (ECP/EPP/PS2/NIBBLE) in ECP+EPP mode (EPP 1.9)
> > > ppbus0: <Parallel port bus> on ppc0
> > > lpt0: <Printer> on ppbus0
> > > lpt0: Polled port
> > > 
> > > 
> > > Under 9.1 the card does not attach the ppc anymore. The hint entries
> > > 
> > > hint.ppc.0.at=puc0
> > > hint.ppc.0.irq=""
> > > hint.ppc.0.flags=0x2F
> > > 
> > > get ignored and so it probes as ppc1 (failing due to the interrupt
> > > problem as it was in 7.4 without hints):
> > > 
> > > puc0: <NetMos NM9835 Dual UART and 1284 Printer port> port 
> > 0xdf00-0xdf07,0xde00-0xde07,0xdd00-0xdd07
> > > ,0xdc00-0xdc07,0xdb00-0xdb07,0xda00-0xda0f irq 17 at device 1.0 on pci4
> > > uart2: <Non-standard ns8250 class UART with FIFOs> at port 1 on puc0
> > > uart3: <16550 or compatible> at port 2 on puc0
> > > ppc1: <Parallel port> at port 3 on puc0
> > > ppc1: Generic chipset (EPP/NIBBLE) in COMPATIBLE mode
> > > ppc1: failed to register interrupt handler: 6
> > > device_attach: ppc1 attach returned 6
> > > 
> > > Any ideas? How do I construct the hint entries under 9.1 so that
> > > 
> > > 1. it does not want to use the interrupt (which made it attach under 
7.4)
> > > 2. it takes the flags 0x2F as it did before.
> > > 
> > > I have also never understood if ppc itself needs to attach to
> > > the irq as well (I thought this all would be handled by puc).
> > 
> > Well, ppc wants to use puc's interrupt, and it should be finding puc's 
> > interrupt.  Ah, I think I found the bug.  Try this patch to 
sys/dev/puc/puc.c:
> > 
> > Index: puc.c
> > ===================================================================
> > --- puc.c	(revision 245225)
> > +++ puc.c	(working copy)
> > @@ -622,7 +628,7 @@ puc_bus_setup_intr(device_t dev, device_t child, s
> >  	if (cookiep == NULL || res != port->p_ires)
> >  		return (EINVAL);
> >  	/* We demand that serdev devices use filter_only interrupts. */
> > -	if (ihand != NULL)
> > +	if (port->p_type == PUC_TYPE_SERIAL && ihand != NULL)
> >  		return (ENXIO);
> >  	if (rman_get_device(port->p_ires) != originator)
> >  		return (ENXIO);
> > 
> > This should let your ppc device re-use IRQ 17 from your puc device.
> 
> True, this really makes ppc use puc's interrupt: I removed
> my local hack (more on this later) which brought the lost
> hint.ppc.0.flags functionality back and applied the patch.
> Now ppc attaches to puc without errors and which also is
> confirmed by lpt:
> 
> lpt0: <Printer> on ppbus0
> lpt0: Interrupt-driven port
> 
> (And, yes, I even printed a page with it ;-))

Great!  I've committed that fix to HEAD and will MFC.
 
> I have no idea if this has ever worked before -- in FreeBSD-7 I
> also had to use the "do not use interrupt"-flag 0x20 in loader.conf
> or ppc wouldn't have attached...
> 
> Which brings me back to the initial problem: Hints like
> 
> hint.ppc.0.at=puc0
> hint.ppc.0.irq=""
> hint.ppc.0.flags=0x2F
> 
> seems to be ignored in 9.1. While the interrupt thing seems
> to be fixed now, one possibly still wants to used the other
> flags. I have helped myself with this (ugly) patch to ppc
> 
> --- ppc.c.ORI 2013-01-12 18:07:44.000000000 +0100
> +++ ppc.c       2013-01-12 18:07:24.000000000 +0100
> @@ -1729,6 +1729,11 @@
>         ppc->ppc_base = rman_get_start(ppc->res_ioport);
>  
>         ppc->ppc_flags = device_get_flags(dev);
> +  if( ppc->ppc_flags == 0 ) {
> +    int tmp;
> +    if( resource_int_value( "ppc" , device_get_unit( dev ), "flags", &tmp) 
== 0 )
> +      ppc->ppc_flags = tmp;
> +  }
>  
>         if (!(ppc->ppc_flags & 0x20)) {
>                 ppc->res_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ,
> 
> in order to get at least the flags applied as it was the case
> before in FreeBSD-7. Unfortuantely, I have no idea how to fix
> that properly ;-(...

This should not be needed for "flags".  Look for 'devflags' in 
sys/kern/subr_bus.c.  The kernel always reads the current 'flags' hint during 
device probe and stores them in dev->devflags and leaves them there after a 
successful probe (so they should be seen by attach).  Specifically, note:

		/* Set the winning driver, devclass, and flags. */
		if (!child->devclass) {
			result = device_set_devclass(child, best->driver->name);
			if (result != 0)
				return (result);
		}
		result = device_set_driver(child, best->driver);
		if (result != 0)
			return (result);
		resource_int_value(best->driver->name, child->unit,
		    "flags", &child->devflags);

This 'devflags' variable is what device_get_flags() returns.  You should be 
able to just place 'hint.ppc.0.flags=0x2f' in /boot/device.hints (note, no 
other hints meaning no "at", etc.)  Perhaps try adding some debug printfs
in subr_bus.c to make sure this is fetching the flags you expect?

-- 
John Baldwin