[PATCH 1/2] ARM: sa1100: fix 3.6864MHz clock

[Dmitry Eremin-Solenikov]

2016-08-19 14:51 GMT+03:00 Russell King <rmk+kernel at armlinux.org.uk>:
> pxa_timer wants to be able to call clk_enable() etc on this clock,
> but our clk_enable() implementation expects non-NULL enable/disable
> operations.  Provide these dummy implementations.

Acked-by: Dmitry Eremin-Solenikov <dbaryshkov at gmail.com>


>
> Unable to handle kernel NULL pointer dereference at virtual address 00000000
> pgd = c0204000
> [00000000] *pgd=00000000
> Internal error: Oops: 80000005 [#1] ARM
> Modules linked in:
> CPU: 0 PID: 0 Comm: swapper Not tainted 4.8.0-rc2+ #887
> Hardware name: Intel-Assabet
> task: c0644590 task.stack: c0640000
> PC is at 0x0
> LR is at clk_enable+0x40/0x58
> pc : [<00000000>]    lr : [<c021b178>]    psr: 600000d3
> sp : c0641f60  ip : c0641f4c  fp : c0641f74
> r10: c1ffc7a0  r9 : 6901b118  r8 : 00000001
> r7 : c0639a34  r6 : 0000001b  r5 : a00000d3  r4 : c0645d70
> r3 : c0645d78  r2 : 00000001  r1 : c0641ef0  r0 : c0645d70
> Flags: nZCv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment none
> Control: c020717f  Table: c020717f  DAC: 00000053
> Process swapper (pid: 0, stack limit = 0xc0640188)
> Stack: (0xc0641f60 to 0xc0642000)
> 1f60: 00384000 c08762e4 c0641f98 c0641f78 c063308c c021b144 00000000 00000000
> 1f80: 00000000 c0660b20 ffffffff c0641fa8 c0641f9c c06220ec c0633058 c0641fb8
> 1fa0: c0641fac c061f114 c06220dc c0641ff4 c0641fbc c061bb68 c061f0fc ffffffff
> 1fc0: ffffffff 00000000 c061b6cc c0639a34 c0660cd4 c0642038 c0639a30 c0645434
> 1fe0: c0204000 c06380f8 00000000 c0641ff8 c0208048 c061b954 00000000 00000000
> Backtrace:
> [<c021b138>] (clk_enable) from [<c063308c>] (pxa_timer_nodt_init+0x40/0x120)
>  r5:c08762e4 r4:00384000
> [<c063304c>] (pxa_timer_nodt_init) from [<c06220ec>] (sa1100_timer_init+0x1c/0x20)
>  r6:ffffffff r5:c0660b20 r4:00000000
> [<c06220d0>] (sa1100_timer_init) from [<c061f114>] (time_init+0x24/0x2c)
> [<c061f0f0>] (time_init) from [<c061bb68>] (start_kernel+0x220/0x42c)
> [<c061b948>] (start_kernel) from [<c0208048>] (0xc0208048)
>  r10:c06380f8 r8:c0204000 r7:c0645434 r6:c0639a30 r5:c0642038 r4:c0660cd4
> Code: bad PC value
> ---[ end trace 0000000000000000 ]---
> Kernel panic - not syncing: Attempted to kill the idle task!
>
> Fixes: ee3a4020f7c9 ("ARM: 8250/1: sa1100: provide OSTIMER0 clock for pxa_timer")
> Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
> ---
> This change first, before patch 2, to avoid the above oops during
> bisects.
>
>  arch/arm/mach-sa1100/clock.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm/mach-sa1100/clock.c b/arch/arm/mach-sa1100/clock.c
> index cbf53bb9c814..0bf3220988ef 100644
> --- a/arch/arm/mach-sa1100/clock.c
> +++ b/arch/arm/mach-sa1100/clock.c
> @@ -125,6 +125,8 @@ static unsigned long clk_36864_get_rate(struct clk *clk)
>  }
>
>  static struct clkops clk_36864_ops = {
> +       .enable         = clk_cpu_enable,
> +       .disable        = clk_cpu_disable,
>         .get_rate       = clk_36864_get_rate,
>  };
>
> --
> 2.1.0
>



-- 
With best wishes
Dmitry