[PATCH] ARM: imx: gpc: Initialize all power domains

[Lucas Stach]

Am Mittwoch, den 19.10.2016, 22:15 +0800 schrieb Shawn Guo:
> On Tue, Oct 11, 2016 at 02:53:33PM -0300, Fabio Estevam wrote:
> > When booting a kernel built with multi_v7_defconfig the following
> > probe error is seen:
> > 
> > imx-gpc: probe of 20dc000.gpc failed with error -22
> > 
> > Later on the kernel crashes like this:
> > 
> > [    1.723358] Unable to handle kernel NULL pointer dereference at virtual address 00000040
> > [    1.731500] pgd = c0204000
> > [    1.731863] hctosys: unable to open rtc device (rtc0)
> > [    1.739301] [00000040] *pgd=00000000
> > [    1.739310] Internal error: Oops: 5 [#1] SMP ARM
> > [    1.739319] Modules linked in:
> > [    1.739328] CPU: 1 PID: 95 Comm: kworker/1:4 Not tainted 4.8.0-11897-g6b5e09a #1
> > [    1.739331] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
> > [    1.739352] Workqueue: pm genpd_power_off_work_fn
> > [    1.739356] task: ee63d400 task.stack: ee70a000
> > [    1.739365] PC is at mutex_lock+0xc/0x4c
> > [    1.739374] LR is at regulator_disable+0x2c/0x60
> > [    1.739379] pc : [<c0bc0da0>]    lr : [<c06e4b10>]    psr: 60000013
> > [    1.739379] sp : ee70beb0  ip : 10624dd3  fp : ee6e6280
> > [    1.739382] r10: eefb0900  r9 : 00000000  r8 : c1309918
> > [    1.739385] r7 : 00000000  r6 : 00000040  r5 : 00000000  r4 : 00000040
> > [    1.739390] r3 : 0000004c  r2 : 7fffd540  r1 : 000001e4  r0 : 00000040
> > 
> > The gpc probe fails because of_genpd_add_provider_onecell() checks
> > if all the domains are initialized via pm_genpd_present() function
> > and it returns an error on the multi_v7_defconfig case.
> 
> It's not clear to me why this is only with multi_v7_defconfig, not
> imx_v6_v7_defconfig.  Also, is it a regression or long-standing issue?

It's a regression in v4.9 and should be applied as a fix.

I don't see the crash on imx_v6_v7_defconfig, but without this patch the
GPC no longer probes correctly on v4.9 and other dependent devices will
not show up at all.

Regards,
Lucas