Re: [Adeos-main] [PATCH 3/3] Fix imx time reprogramming issue

[Michael Trimarchi <michael@domain.hid>]

Hi

On 04/24/2012 10:53 AM, Gilles Chanteperdrix wrote:
> On 04/24/2012 10:32 AM, Michael Trimarchi wrote:
>> On 04/24/2012 10:13 AM, Gilles Chanteperdrix wrote:
>>> On 04/24/2012 10:09 AM, Michael Trimarchi wrote:
>>>> This patch includes:
>>>>
>>>> * Fix invalid virtual address base of MX1_2_TCM
>>>> * Fix the minimum delay below which the hardware timer can not be reprogrammed.
>>>>   The value is the same of that one that is used to calculate the min_delta_ns
>>>>
>>>> arch/arm/plat-mxc/time.c
>>>> 414: clockevent_mxc.min_delta_ns = clockevent_delta2ns(0xff, &clockevent_mxc);
>>>
>>> I do not think we can use this value, it is way to high for xenomai
>>> needs. In latest releases we use 2us instead of 1us, and according to
>>> what a user posted recently, this should be enough, could you test with
>>> 2us? And 2us is already what we have in the 3.2 repository.
>>>
>> As I understood the min delays is in tick and not depend on the clock rate. 
>>
>> This is from atmel at91_ipipe_time
>>
>> min_delta_ticks = ((unsigned long long) clkevt.min_delta_ns
>>                            * clkevt.mult) >> clkevt.shift;
>>
>> this is exaclty the reverse calculation of clockevent_mxc.min_delta_ns
>>
>> I have already the result in the previous calculation: 0xff is the minimun in ticks
> 
> 0xff is too large, it corresponds to 30us on some platforms, could you
> please try with 2us? The delay is given as a count of ticks or as a
> duration in ns depending on the architecture, it does not really matter.
> 

Ok, with 0x85 is working (2 uS). I don't find in the documentation the min_delta_ns for this architecture. I will rebase the patch on core-3.2

Michael

>>
>> Michael
>>
> 
> 


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| Michael Nazzareno Trimarchi                     Amarula Solutions BV |
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