[U-Boot] [PATCH] [Timer]Remove calls to [get, reset]_timer outside arch/

[Graeme Russ <graeme.russ@gmail.com>]

On 24/05/11 04:29, Scott McNutt wrote:
> Hi Bill,
> 
> J. William Campbell wrote:
>> On 5/23/2011 6:12 AM, Scott McNutt wrote:
>>> Dear Graeme,
>>>
>>> Graeme Russ wrote:
>>>> On 23/05/11 22:19, Scott McNutt wrote:
>>>>> Hi Graeme,
>>>>>
>>>>> Graeme Russ wrote:
>>>>>> There is no need to use get_timer() and reset_timer() and there are
>>>>>> build
>>>>> I must have missed something WRT reset_timer() -- my apologies
>>>>> if I'm covering old ground.
>>>>>
>>>>> When the timestamp is incremented using an interrupt that occurs with
>>>>> a period greater than 1 ms, we can get early timeouts. reset_timer()
>>>>> solved the problem. What's the recommended approach for dealing with
>>>>> this without reset_timer() ?
>> Hi Scott,
>>           Are you saying that the interrupt frequency is greater than
>> 1000 times per second, or as I read it, the frequency is less than 1000
>> per second (period greater than 1 ms). If anything, that should make the
>> timer run slow, not fast.
>>  I wonder if it is a resolution issue. What are the typical delays in ms
>> you are using?
> 
> Some older nios2 implementations have _fixed_ 10 msec timers.
> Basically, the timestamp is incremented asynchronous to get_timer(0).
> So a  10 msec timeout can occur, for example, almost immediately if
> the timer isn't reset just prior to calling get_timer(0). There are
> more details in the comments for the following commits:
> 
> nios2: Reload timer count in reset_timer():
>   d8bc0a2889700ba063598de6d4e7d135360b537e
> 
> cfi_flash: reset timer in flash status check:
>   22d6c8faac4e9fa43232b0cf4da427ec14d72ad3
> 
> I'm totally in favor of cleaning this stuff up. It caused some
> headaches (and wasted time) about 13 months ago. My primary concern
> is to avoid breaking things that currently work for us nios2
> weenies ... at least for any length of time.
> 
> Things are a bit tight for me until next week or so. I'll probably
> come up for air around June 1st ... and I'll be glad to help out.
> 

Is there any reason why we cannot silently perform a reset_timer() any time
set_timer() is called with a parameter of 0?

Regards,

Graeme