linux-spi.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Jander <david@protonic.nl>
To: "Pankajkumar Misra (RBEI/EEA2)" <Pankaj.Kumar@in.bosch.com>
Cc: "linux-spi@vger.kernel.org" <linux-spi@vger.kernel.org>,
	"linux-can@vger.kernel.org" <linux-can@vger.kernel.org>,
	gianluca <gianlucarenzi@eurekelettronica.it>
Subject: Re: MCP2515 implementation is slow
Date: Thu, 27 Nov 2014 08:33:46 +0100	[thread overview]
Message-ID: <20141127083346.79d4a5af@archvile> (raw)
In-Reply-To: <84a1d29551f84f5494b309e1ad1e0840@SGPMBX1004.APAC.bosch.com>

On Tue, 25 Nov 2014 16:19:33 +0000
"Pankajkumar Misra (RBEI/EEA2)" <Pankaj.Kumar@in.bosch.com> wrote:

> I have compiled MCP251x.c kernel driver module for Olimex A20-Olinuxino
> Micro.
> 
> The device is working fine for one frame at a time at 500ms. If I send two
> or more frame at the same time, CAN is going to bus-off due to overrun
> errors. Even if I send one frame at faster rate say, 100ms,results in
> bus-off.

I tend to think there is something other wrong with your setup. Maybe you are
missing bus-termination/biasing? Chip-clock?
The device should never go in bus-off mode if there are RX-overruns. If it
goes into bus-off, there is something wrong in the hardware.

> I am communicating with module with ip commands, cansend & candump.
> Also my SPI module is working only at 250K baud, not any other baud.

We use a MCP2515 with this driver at 250kbit/s receiving back-to-back messages
without loss on a i.MX51. Please note, that it won't work reliably at any
higher bitrate and system load is quite high.

The MCP2515 is a very bad design, but the driver performance has improved a lot
since spi-bitbang started using a kthread instead of a work-queue.

> Any suggestions.
> 
> Best Regards,
> Pankaj
> --
> To unsubscribe from this list: send the line "unsubscribe linux-can" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Best regards,

-- 
David Jander
Protonic Holland.

      reply	other threads:[~2014-11-27  7:33 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-25 16:19 MCP2515 implementation is slow Pankajkumar Misra (RBEI/EEA2)
2014-11-27  7:33 ` David Jander [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20141127083346.79d4a5af@archvile \
    --to=david@protonic.nl \
    --cc=Pankaj.Kumar@in.bosch.com \
    --cc=gianlucarenzi@eurekelettronica.it \
    --cc=linux-can@vger.kernel.org \
    --cc=linux-spi@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).