Re: [PATCH] ARM: dts: Update arch timer node with clock frequency

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 09/20/2013 04:17 AM, Marc Zyngier wrote:
> On 20/09/13 05:57, Yuvaraj Kumar wrote:
>> Resending it as it bounced from kernel mailing group
>>
>> On Wed, Sep 18, 2013 at 3:53 PM, Mark Rutland <mark.rutland@xxxxxxx> wrote:
>>> [adding lakml]
>>>
>>> On Wed, Sep 18, 2013 at 11:11:53AM +0100, Yuvaraj Kumar C D wrote:
>>>> Without the "clock-frequency" property in arch timer node, could able
>>>> to see the below crash dump.
>>>
>>> Why does this cause the below crash specifically? What is CNTFRQ reading
>>> as?
>> Return value of arch_timer_get_cntfrq() is 0
>>>
>>> Your firmware or bootloader should set CNTFRQ -- setting the
>>> clock-frequency is a work-around for buggy firmware/bootloaders that
>>> should be avoided as far as possible.
>> Why kernel should depend on bootloader/firmware  to set CNTFRQ? Any
>> specific reasons?
> 
> Because the kernel can't set it if running non-secure. Only secure mode
> can do this (see the ARM ARM for details).

What software outside the kernel actually reads the CNTFRQ and why?

Thanks,
Christopher

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by the Linux Foundation.
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux SoC Development]     [Linux Rockchip Development]     [Linux USB Development]     [Video for Linux]     [Linux Audio Users]     [Linux SCSI]     [Yosemite News]

  Powered by Linux