Re: Fwd: realtime performance of adl_pci9118

On Thu, 13 Oct 2005, wicky Zhang wrote:

> ---------- Forwarded message ----------
> From: wicky Zhang <wicky.zhang_at_gmail.com>
> Date: Oct 13, 2005 9:22 PM
> Subject: Re: realtime performance of adl_pci9118
> To: Michal Dobes <dobes_at_tesnet.cz>
> Cc: rtai_at_rtai.org
>
>
>
> do you use cmd->flags|=TRIG_WAKE_EOS ?
>> If yes, then after every sample is generated interrupt and 50
>> kinterrupts/s
>> will kill any system.
>
>  I have not do that operation, but would you tell me how to check this
> setting
>  or reset it?

Just make sure cmd->flags doesn't contain the TRIG_WAKE_EOS bit.
  If you didn't set it, it should be off by itself (you *did* memset() your 
comedi_cmd struct to 0, right?  Either that or it is a global var, 
right?).

If you want to be paranoid (something I always encourage), read the 
sources to your driver to make sure it doesn't default to have the board 
interrupt after each scan -- if it does that (and the driver supports 
not-interrupting-after-each-scan) that's a bug.

Also, as someone else suggested, try and make sure the board is doing DMA 
transfers (by figuring out if the driver is using DMA).

-Calin

Received on 2005-10-15Z23:25:37