lkml.org 
[lkml]   [2011]   [May]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v4 1/1] can: add pruss CAN driver.
    On 05/23/2011 08:21 AM, Oliver Hartkopp wrote:

    [...]

    > In 'real world' CAN setups you'll never see 21.000 CAN frames per second (and
    > therefore 21.000 irqs/s) - you are usually designing CAN network traffic with
    > less than 60% busload. So interrupt rates somewhere below 1000 irqs/s can be
    > assumed.
    >
    > From what i've seen so far a 3-4 messages rx FIFO and NAPI support just make it.
    >
    > @Marc/Wolfgang: Would this be also your recommendation for a CAN controller
    > design that supports SocketCAN in the best way?

    If you have a rx FIFO NAPI is the way to go. For a single mailbox it
    adds overhead, if you can read the CAN frame in the interrupt handler.
    The error messages should probably generated from NAPI, too. Especially
    the I'm-the-only-CAN-node-on-the-net-and-get-no-ACK error message.

    However IIRC David said that every new driver should implement NAPI.

    > As the Linux network stack supports hardware timestamps too, this could be an
    > additional (optional!) feature.

    regards, Marc
    --
    Pengutronix e.K. | Marc Kleine-Budde |
    Industrial Linux Solutions | Phone: +49-231-2826-924 |
    Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
    Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |

    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2011-05-23 10:25    [W:0.024 / U:0.576 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site