Messages in this thread | | | Date | Tue, 21 Apr 2015 12:19:48 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH v2] irqchip/gicv3-its: ITS table size should not be smaller than PSZ |
| |
On Thu, 16 Apr 2015, Minghuan Lian wrote:
> The default page size of ITS table has been changed to 64KB, > but for some platforms the real size of allocated memory which > calculated by DEVBITS of register GITS_TYPER may be smaller than > default size. In this case, the allocation size must be increased > to the default size, otherwise, the wrong page number will cause > kernel hang.
This changelog fails to explain WHY the kernel hangs if the allocated table is smaller than the default
> Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com> > --- > v2-v1: > Increase allocation size instead of decreasing PSZ > > drivers/irqchip/irq-gic-v3-its.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index 9687f8a..19ab86d 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -828,7 +828,8 @@ static int its_alloc_tables(struct its_node *its) > u64 typer = readq_relaxed(its->base + GITS_TYPER); > u32 ids = GITS_TYPER_DEVBITS(typer); > > - order = get_order((1UL << ids) * entry_size); > + order = max(get_order((1UL << ids) * entry_size), > + order);
Lacks a comment explaining WHY we do that max() here.
Thanks,
tglx
| |