From: Marc Kleine-Budde <mkl@pengutronix.de>
To: David Jander <david@protonic.nl>, wg@grandegger.com
Cc: linux-can@vger.kernel.org
Subject: Re: [PATCH 2/3] can: flexcan.c: Re-write receive path to use MB queue instead of FIFO
Date: Tue, 02 Sep 2014 13:30:24 +0200 [thread overview]
Message-ID: <5405AA50.6040100@pengutronix.de> (raw)
In-Reply-To: <1409133487-23367-3-git-send-email-david@protonic.nl>
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On 08/27/2014 11:58 AM, David Jander wrote:
> The FlexCAN controller has a RX FIFO that is only 6 messages deep, and a
> mailbox space capable of holding up to 63 messages.
> This space was largely unused, limiting the permissible latency from
> interrupt to NAPI to only 6 messages. This patch uses all available MBs
> for message reception and frees the MBs in the IRQ handler to greatly
> decrease the likelihood of receive overruns.
What about the order of the incoming CAN frames? Is it still preserved?
You make use of the CTRL2 register, which is not present on some older
(but supported) flexcan IP cores. You increase FLEXCAN_MCR_MAXMB to
0x40, which is not supported on older IPs. The register rximr, is also
not present on older cores. Don't break support for the older CAN cores.
Please make this patch based on linux-can-next/master (which holds some
updates to the regs structure).
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
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next prev parent reply other threads:[~2014-09-02 11:30 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-27 9:58 [PATCH 0/3] Decrease likelyhood of RX overruns David Jander
2014-08-27 9:58 ` [PATCH 1/3] can: flexcan.c: Correctly initialize mailboxes David Jander
2014-09-02 10:24 ` Marc Kleine-Budde
2014-09-02 10:37 ` David Jander
2014-09-02 10:59 ` Marc Kleine-Budde
2014-09-02 11:15 ` David Jander
2014-09-02 13:54 ` Marc Kleine-Budde
2014-09-02 14:27 ` David Jander
2014-09-02 11:32 ` David Jander
2014-09-02 11:38 ` Marc Kleine-Budde
2014-09-02 14:53 ` Marc Kleine-Budde
2014-08-27 9:58 ` [PATCH 2/3] can: flexcan.c: Re-write receive path to use MB queue instead of FIFO David Jander
2014-09-02 11:30 ` Marc Kleine-Budde [this message]
2014-09-02 12:04 ` David Jander
2014-09-02 14:53 ` Marc Kleine-Budde
2014-09-03 7:19 ` David Jander
2014-09-03 9:12 ` Marc Kleine-Budde
2014-09-03 15:42 ` David Jander
2014-08-27 9:58 ` [PATCH 3/3] can: flexcan.c: Implement last step of workaround for errata ERR005829 David Jander
2014-09-02 11:28 ` Marc Kleine-Budde
2014-09-02 11:36 ` David Jander
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