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 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
