On Wed, 7 Jan 2015, Roger Quadros wrote:
> > From: Paul Walmsley <p...@pwsan.com>
> > Date: Mon, 5 Jan 2015 15:49:57 -0700
> > Subject: [PATCH] Only skip ioremap() if IP block does not have OCP header
> > registers. Experimental.
> >
> > ---
> > arch/arm/mach-omap2/omap_hwmod.c | 33 +++++++++++++++++++++------------
> > 1 file changed, 21 insertions(+), 12 deletions(-)
> >
> > diff --git a/arch/arm/mach-omap2/omap_hwmod.c
> > b/arch/arm/mach-omap2/omap_hwmod.c
> > index cbb908dc5cf0..03df8833d399 100644
> > --- a/arch/arm/mach-omap2/omap_hwmod.c
> > +++ b/arch/arm/mach-omap2/omap_hwmod.c
> > @@ -1938,6 +1938,8 @@ static int _reset(struct omap_hwmod *oh)
> > pr_debug("omap_hwmod: %s: resetting\n", oh->name);
> >
> > if (oh->class->reset) {
> > + WARN(!oh->_mpu_rt_va, "Attempt to call custom reset with no MPU
> > register target ioremapped: %s",
> > + oh->name);
>
> Not part of $subject.
Hmm, how do you mean? If we skip the ioremap(), wouldn't you like to know
before some custom reset code gets called that pretty much always depends
on the ioremap() succeeding? :-)
> > r = oh->class->reset(oh);
> > } else {
> > if (oh->rst_lines_cnt > 0) {
> > @@ -2358,15 +2360,19 @@ static int of_dev_hwmod_lookup(struct device_node
> > *np,
> > }
> >
> > /**
> > - * _init_mpu_rt_base - populate the virtual address for a hwmod
> > + * _init_mpu_rt_base - populate the MPU port and virtual address
> > * @oh: struct omap_hwmod * to locate the virtual address
> > * @data: (unused, caller should pass NULL)
> > * @index: index of the reg entry iospace in device tree
> > * @np: struct device_node * of the IP block's device node in the DT data
> > *
> > - * Cache the virtual address used by the MPU to access this IP block's
> > - * registers. This address is needed early so the OCP registers that
> > - * are part of the device's address space can be ioremapped properly.
> > + * Cache the interconnect target port and the virtual address used by
> > + * the MPU to access this IP block's registers. The address is needed
> > + * early so the OCP registers that are part of the device's address
> > + * space can be ioremapped properly. The presence or absence of the
> > + * interconnect target port also indicates whether the hwmod code
> > + * should wait for the IP block to indicate readiness after it is
> > + * enabled.
> > *
> > * Returns 0 on success, -EINVAL if an invalid hwmod is passed, and
> > * -ENXIO on absent or invalid register target address space.
> > @@ -2385,6 +2391,13 @@ static int __init _init_mpu_rt_base(struct
> > omap_hwmod *oh, void *data,
> > if (oh->_int_flags & _HWMOD_NO_MPU_PORT)
> > return -ENXIO;
> >
> > + /*
> > + * If there's no need for the hwmod code to read or write to
> > + * the IP block registers, bail out early before the ioremap()
> > + */
> > + if (!oh->class->sysc)
> > + return 0;
> > +
> > mem = _find_mpu_rt_addr_space(oh);
> > if (!mem) {
> > pr_debug("omap_hwmod: %s: no MPU register target found\n",
> > @@ -2451,14 +2464,10 @@ static int __init _init(struct omap_hwmod *oh, void
> > *data)
> > oh->name, np->name);
> > }
> >
> > - if (oh->class->sysc) {
> > - r = _init_mpu_rt_base(oh, NULL, index, np);
> > - if (r < 0) {
> > - WARN(1, "omap_hwmod: %s: doesn't have mpu register
> > target base\n",
> > - oh->name);
> > - return 0;
> > - }
> > - }
> > + r = _init_mpu_rt_base(oh, NULL, index, np);
> > + if (r < 0)
> > + pr_debug("omap_hwmod: %s: doesn't have mpu register target
> > base\n",
> > + oh->name);
>
> This is the real piece that fixes the issue.
>
> >
> > r = _init_clocks(oh, NULL);
> > if (r < 0) {
> >
>
> I've tested this patch on am43x-gp-evm, and it seems to fix the issue
> although with some unpleasant warning messages.
Could you paste those in?
- Paul
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