From: Marc Kleine-Budde <mkl@pengutronix.de>
To: David Jander <david@protonic.nl>
Cc: linux-can@vger.kernel.org
Subject: Re: RFC: [PATCH v2] can: flexcan: Implement errata ERR005829
Date: Tue, 16 Sep 2014 14:58:01 +0200 [thread overview]
Message-ID: <541833D9.2060607@pengutronix.de> (raw)
In-Reply-To: <20140916142846.2ae8335c@archvile>
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On 09/16/2014 02:28 PM, David Jander wrote:
>>> Please note that if the silicon bug didn't exist, none of the two writes
>>> would be necessary.
>>> Once you create a quirk for this, how are we supposed to know which
>>> versions need this quirk, and which don't? Can we trust the existence of
>>> erratas for the different i.MX Soc's, and should we just go and check them
>>> all?
>>
>> I had a patch with the quirk, but I removed it, as you suggested, just
>> in case.
>
> I did not directly suggest to NOT use a quirk, I only had some concerns. In
Not directly, but between the lines :D
> the meantime I have checked a few of the SoCs for erratas, and found this
> errata only for i.MX6 and Vybrid VF6xx, which makes me suspect this problem is
> unique to IP version 10 (if the IP version table at the beginning of the
> source-code is to be trusted).
We don't even know the IP version of the flexcan core on the vybrid, it
has different features than the imx6 one.
> OTOH, if you decided to leave the unconditional writes in there, I am fine
> with that. I don't think they do much harm.
>
> Is it time to revisit my other patch(es) yet? If so, from where should I pull
> the base?
Sorry, no time yet, but I've found another (luckily only a minor)
problem with the mailboxes. After sending a RTR frame the TX mailbox
gets automatically converted into a RX one.
See imx6 data sheet Table 26-5. Message Buffer Code for Tx buffers:
> Transmit remote request frame unconditionally once. After
> transmission, the MB automatically becomes an Rx Empty MB
> with the same ID.
I'll prepare a patch.
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 |
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next prev parent reply other threads:[~2014-09-16 12:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-03 14:47 RFC: [PATCH v2] can: flexcan: Implement errata ERR005829 David Jander
[not found] ` <54081940.6060402@pengutronix.de>
[not found] ` <20140904104440.5766d764@archvile>
2014-09-16 11:48 ` Marc Kleine-Budde
2014-09-16 12:28 ` David Jander
2014-09-16 12:58 ` Marc Kleine-Budde [this message]
2014-09-16 14:29 ` Marc Kleine-Budde
2014-09-18 13:50 ` David Jander
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