[PATCH/RFC] ARM: shmobile: r8a7779: Update early timer initialisation order
Magnus Damm
magnus.damm at gmail.com
Wed Aug 28 02:58:39 EDT 2013
Hi Simon,
On Thu, Aug 22, 2013 at 4:39 PM, Simon Horman <horms at verge.net.au> wrote:
> On Fri, Aug 09, 2013 at 05:37:39PM +0900, Magnus Damm wrote:
>> On Thu, Aug 8, 2013 at 5:59 PM, Simon Horman <horms+renesas at verge.net.au> wrote:
>> > a894fcc2d01a89e6fe3da0845a4d80a5312e1124 ("ARM: smp_twd: Divorce smp_twd
>> > from local timer API") altered twd_local_timer_common_register() so that it
>> > may make use of late_timer_init.
>> >
>> > This is problematic on marzen with Magnus's recent patch "ARM: shmobile:
>> > marzen: Switch to DT_MACHINE_START" which switches marzen around to enable
>> > USE_OF and thus shmobile_timer_init(), which is registered as
>> > late_time_init by shmobile_earlytimer_init() stops being a no-op.
>> >
>> > As a work-around I have updated r8a7779_earlytimer_init() so that
>> > shmobile_earlytimer_init() is called after r8a7779_register_twd().
>> > Or in other words, the shmobile_earlytimer_init() setting of
>> > late_time_init overwrites that of twd_local_timer_common_register().
>> >
>> > Cc: Stephen Boyd <sboyd at codeaurora.org>
>> > Cc: Magnus Damm <magnus.damm at gmail.com>
>> > Signed-off-by: Simon Horman <horms+renesas at verge.net.au>
>> >
>> > ---
>> >
>> > This patch was created on top of a merge of next-20130807 from the
>> > linux-next tree and renesas-next-20130807 from my renesas tree.
>> >
>> > I expect the problem describe above to be present in the
>> > next version of linux-next as it will include renesas-next-20130807.
>> >
>> > I rather suspect that this fix is just papers over the problem
>> > at hand rather than fixing it. But it does at least fix the problem
>> > to the extent where the marzen board at least boots.
>> >
>> > For reference the output of /proc/interrupts after such a boot is below.
>> >
>> > CPU0 CPU1 CPU2 CPU3
>> > 29: 0 9365 9363 9359 GIC 29 twd
>> > 59: 0 0 0 0 GIC 59 renesas_intc_irqpin.0
>> > 60: 5 0 0 0 GIC 60 renesas_intc_irqpin.0
>> > 61: 0 0 0 0 GIC 61 renesas_intc_irqpin.0
>> > 62: 0 0 0 0 GIC 62 renesas_intc_irqpin.0
>> > 64: 278 0 0 0 GIC 64 sh_tmu.0
>> > 76: 1 0 0 0 GIC 76 ehci_hcd:usb1, ohci_hcd:usb3
>> > 77: 1 0 0 0 GIC 77 ehci_hcd:usb2, ohci_hcd:usb4
>> > 111: 0 0 0 0 GIC 111 i2c-rcar.0
>> > 112: 0 0 0 0 GIC 112 i2c-rcar.2
>> > 113: 0 0 0 0 GIC 113 i2c-rcar.3
>> > 114: 0 0 0 0 GIC 114 i2c-rcar.1
>> > 122: 45 0 0 0 GIC 122 sh-sci.2:mux
>> > 132: 0 0 0 0 GIC 132 sata_rcar
>> > 173: 0 0 0 0 GIC 173 gpio_rcar.0
>> > 174: 0 0 0 0 GIC 174 gpio_rcar.1
>> > 175: 0 0 0 0 GIC 175 gpio_rcar.2
>> > 176: 0 0 0 0 GIC 176 gpio_rcar.3
>> > 177: 0 0 0 0 GIC 177 gpio_rcar.4
>> > 178: 0 0 0 0 GIC 178 gpio_rcar.5
>> > 179: 0 0 0 0 GIC 179 gpio_rcar.6
>> > 2001: 5 0 0 0 renesas_intc_irqpin.0 1 eth0
>> > IPI0: 0 0 0 0 CPU wakeup interrupts
>> > IPI1: 0 0 0 0 Timer broadcast interrupts
>> > IPI2: 314 340 58 33 Rescheduling interrupts
>> > IPI3: 22 56 34 56 Function call interrupts
>> > IPI4: 0 0 0 0 Single function call interrupts
>> > IPI5: 0 0 0 0 CPU stop interrupts
>> > Err: 0
>> > ---
>> > arch/arm/mach-shmobile/setup-r8a7779.c | 2 +-
>> > 1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/arch/arm/mach-shmobile/setup-r8a7779.c b/arch/arm/mach-shmobile/setup-r8a7779.c
>> > index ddee4aa..b0f56d6 100644
>> > --- a/arch/arm/mach-shmobile/setup-r8a7779.c
>> > +++ b/arch/arm/mach-shmobile/setup-r8a7779.c
>> > @@ -597,8 +597,8 @@ void __init __weak r8a7779_register_twd(void) { }
>> > void __init r8a7779_earlytimer_init(void)
>> > {
>> > r8a7779_clock_init();
>> > - shmobile_earlytimer_init();
>> > r8a7779_register_twd();
>> > + shmobile_earlytimer_init();
>> > }
>> >
>> > void __init r8a7779_add_early_devices(void)
>> > --
>> > 1.8.3.2
>> >
>>
>> Hi Simon,
>>
>> Thanks for tracking down this issue. I think your patch looks fine to
>> me.
>
> Thanks, could I get an acked-by ?
Yes, of course.
Acked-by: Magnus Damm <damm at opensource.se>
>> Regarding Marzen DT reference, I don't think TWD is used there yet
>> so I doubt that it will have the same problem as the C version of the
>> marzen board code.
>
> Agreed.
>
>> One related worry is that sh73a0 may have the same
>> issue - or rather - judging by the code in sh73a0_earlytimer_init() it
>> most certainly is affected by this too. So KZM9G should also fail as
>> Marzen which means we need to fix sh73a0 too.
>
> Curiously I do not seem to see the problem on the kzm9d.
> Would you like me to prepare a patch anyway?
I meant kzm9g, not kzm9d. =)
I believe emev2 and kzm9d is most likely OK as-is. (except for the STI
broadcast issue that still is on my TODO)
However sh73a0 and kzm9g probably needs a similar fix as this patch.
When you have time, can you please check?
Thanks,
/ magnus
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