On Fri, 16 Aug 2019 20:41:22 +0200 Lubomir Rintel <[email protected]> wrote:
> On Fri, 2019-08-09 at 13:12 +0100, Marc Zyngier wrote: > > On 09/08/2019 10:31, Lubomir Rintel wrote: > > > The "regs" property of the "mrvl,mmp2-mux-intc" devices are silly. They > > > are offsets from intc's base, not addresses on the parent bus. At this > > > point it probably can't be fixed. > > > > > > On an OLPC XO-1.75 machine, the muxes are children of the intc, not the > > > axi bus, and thus of_address_to_resource() won't work. We should treat > > > the values as mere integers as opposed to bus addresses. > > > > > > Signed-off-by: Lubomir Rintel <[email protected]> > > > Acked-by: Pavel Machek <[email protected]> > > > > > > --- > > > drivers/irqchip/irq-mmp.c | 20 +++++++++++--------- > > > 1 file changed, 11 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/irqchip/irq-mmp.c b/drivers/irqchip/irq-mmp.c > > > index 14618dc0bd396..af9cba4a51c2e 100644 > > > --- a/drivers/irqchip/irq-mmp.c > > > +++ b/drivers/irqchip/irq-mmp.c > > > @@ -424,9 +424,9 @@ IRQCHIP_DECLARE(mmp2_intc, "mrvl,mmp2-intc", > > > mmp2_of_init); > > > static int __init mmp2_mux_of_init(struct device_node *node, > > > struct device_node *parent) > > > { > > > - struct resource res; > > > int i, ret, irq, j = 0; > > > u32 nr_irqs, mfp_irq; > > > + u32 reg[4]; > > > > > > if (!parent) > > > return -ENODEV; > > > @@ -438,18 +438,20 @@ static int __init mmp2_mux_of_init(struct > > > device_node *node, > > > pr_err("Not found mrvl,intc-nr-irqs property\n"); > > > return -EINVAL; > > > } > > > - ret = of_address_to_resource(node, 0, &res); > > > + > > > + /* > > > + * For historical reasonsm, the "regs" property of the > > > + * mrvl,mmp2-mux-intc is not a regular * "regs" property containing > > > + * addresses on the parent bus, but offsets from the intc's base. > > > + * That is why we can't use of_address_to_resource() here. > > > + */ > > > + ret = of_property_read_u32_array(node, "reg", reg, ARRAY_SIZE(reg)); > > > > This will return 0 even if you've read less than your expected 4 u32s. > > You may want to try of_property_read_variable_u32_array instead. > > Will it? Unless I'm reading the of_property_read_u32_array() > documentation wrong, it suggests that would return -EOVERFLOW in that > case. You're appear to be right, and I read it wrong. > > It ignores the extra values it the property is larger. I guess that is > not a good thing and we still want to use > of_property_read_variable_u32_array() though. It doesn't hurt to check for all possible problems, specially given that this machine doesn't appear to have a mainline DT (and its OF implementation looks a bit buggy). Thanks, M. -- Without deviation from the norm, progress is not possible.
