[PATCH/RFC] ARM: shmobile: r8a7779: Update early timer initialisation order
Magnus Damm
magnus.damm at gmail.com
Thu Aug 29 00:13:58 EDT 2013
Hi Simon,
On Thu, Aug 29, 2013 at 10:46 AM, Simon Horman <horms at verge.net.au> wrote:
> On Wed, Aug 28, 2013 at 03:58:39PM +0900, Magnus Damm wrote:
>> 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 meant kzm9g too.
>
>> 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?
>
> I am not seeing the problem on kzm9g.
That's odd. Isn't the early timer init order the same? Is the timer
driver and kernel configuration for timer portion the same when you
compare?
Cheers,
/ magnus
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