interrupt coalescing / polling

John Plevyak jplevyak@inktomi.com
Wed Mar 3 13:14:43 1999


So does this mean I can control the RxDone interrupt on a frame
by frame basis?

I tried adding the interrupt mask to the command portion of the
descriptor but that didn't seem to do it.

I have turned off the interrupts entirely, and this works, but
I would prefer just to reduce them only when I know that
the system is CPU bound.

john


On Fri, Feb 26, 1999 at 07:35:30PM -0500, Donald Becker wrote:
> On Fri, 26 Feb 1999, John Plevyak wrote:
> > On Fri, Feb 26, 1999 at 02:48:41AM -0500, Donald Becker wrote:
> > > On Thu, 25 Feb 1999, John Plevyak wrote:
> > > Unlike most chips the EEPro100 has only a global interrupt mask, not
> > > individual interrupt enables.  You would have to turn off the interrupt bits
> > > on the receive descriptor list.
> 
> Ooops, I was wro.. wron.. wr.. wrr..  ..your understanding of my statement was
> limited ;->
> Specific interrupts, including the RxDone interrupt, on the Speedo3
> (EEPro100B chip) can be masked.
> There is an Rx indication for every received frame.
>   (Definition: "Indication" means "will generate an interrupt if not masked")
> 
> /* Current, bits defined in the driver.*/
> ________________
> #define INT_MASK	0x0100
> #define DRVR_INT	0x0200		/* Driver generated interrupt. */
> ________________
> 
> /* The full list, which I'll add to the driver RSN. */
> ________________
> enum SCBCmdBits {
>      SCBMaskCmdDone=0x8000, SCBMaskRxDone=0x4000, SCBMaskCmdIdle=0x2000,
>      SCBMaskRxSuspend=0x1000, SCBMaskEarlyRx=0x0800, SCBMaskFlowCtl=0x0400,
>      SCBTriggerIntr=0x0200, SCBMaskAll=0x0100,
>      /* The rest are Rx and Tx commands. */
>      CUStart=0x0010, CUResume=0x0020, CUStatsAddr=0x0040, CUShowStats=0x0050,
>      CUCmdBase=0x0060,	/* CU Base address (set to zero) . */
>      CUDumpStats=0x0070, /* Dump then reset stats counters. */
>      RxStart=0x0001, RxResume=0x0002, RxAbort=0x0004, RxAddrLoad=0x0006,
>      RxResumeNoResources=0x0007,
> };
> ________________
> 
> Note that the only the upper four interrupt masks bits match the SCBStatus
> bits!!!
> 
> 
> Donald Becker					  becker@cesdis.gsfc.nasa.gov
> USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
> Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
> 301-286-0882	     http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html
> 

-- 
John Bradley Plevyak,    PhD,    jplevyak@inktomi.com,     PGP KeyID: 051130BD
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