On Tue, Apr 22, 2014 at 02:35:15PM +0100, Grant Likely wrote:
> On Fri, 18 Apr 2014 13:59:24 +0100, Leif Lindholm <leif.lindholm@xxxxxxxxxx> wrote:
> > Hi Geert,
> >
> > On Fri, Apr 18, 2014 at 10:04:15AM +0200, Geert Uytterhoeven wrote:
> > > On Thu, Apr 17, 2014 at 7:42 PM, Leif Lindholm <leif.lindholm@xxxxxxxxxx> wrote:
> > > > In order to deal with an firmware bug on a specific ppc32 platform
> > > > (longtrail), early_init_dt_scan_memory() looks for a node called
> > > > memory@0 on all platforms. Restrict this quirk to ppc32 kernels only.
> > >
> > > This breaks backwards compatibilty with old DTSes (at least on ARM/MIPS,
> > > where you added the missing property in patches 1 and 2 of the series)?
> >
> > As Rob said in response to 0/3, the MIPSs would likely not be affected,
> > since they embed the DT.
> >
> > > For the Longtrail, I don't care much anymore, as mine died in 2004.
> > > AFAIK, there have never been many users anyway.
> >
> > There are still a few mentions of it under arch/powerpc/, so I wouldn't
> > want to be the one to kill it off...
> >
> > How about the below v2 3/3 to address the ARM platform?
>
> The problem with this approach is that selecting one board that needs it
> automatically makes it active for all boards. It would need to be
> something more like the following:
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 399e242e1a42..55d65b2b4c74 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -887,12 +887,10 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
>
> /* We are scanning "memory" nodes only */
> if (type == NULL) {
> - /*
> - * The longtrail doesn't have a device_type on the
> - * /memory node, so look for the node called /memory@0.
> - */
> if (depth != 1 || strcmp(uname, "memory@0") != 0)
> return 0;
> + if (!of_flat_dt_match(dt_root, memory_quirk_list))
> + return 0;
> } else if (strcmp(type, "memory") != 0)
> return 0;
>
> With a list of compatible properties for affected boards.
That looks sane to me.
Does anyone have a LongTrail DT to hand, and if so does the root have a
compatible string? From grepping through the kernel I could only find a
model string ("IBM,LongTrail").
Is anyone aware of strings other than that and "st-ericsson,ccu8540" to
look out for?
Cheers,
Mark.
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
