From: Arnaud Patard (Rtp) <arnaud.patard@rtp-net•org>
To: Thomas Petazzoni <thomas.petazzoni@free-electrons•com>
Cc: netdev@vger•kernel.org, "Lior Amsalem" <alior@marvell•com>,
"Gregory Clément" <gregory.clement@free-electrons•com>,
"Ezequiel Garcia" <ezequiel.garcia@free-electrons•com>
Subject: Re: [patch 2/2] Try to fix mvneta when compiled as module
Date: Mon, 24 Jun 2013 09:43:55 +0200 [thread overview]
Message-ID: <87txko9cn8.fsf@lebrac.rtp-net.org> (raw)
In-Reply-To: <20130623100617.1457a2a8@skate> (Thomas Petazzoni's message of "Sun, 23 Jun 2013 10:06:17 +0200")
Thomas Petazzoni <thomas.petazzoni@free-electrons•com> writes:
> Dear Arnaud Patard (Rtp),
>
> On Fri, 21 Jun 2013 00:06:46 +0200, Arnaud Patard (Rtp) wrote:
>
>> This patch sets the "sgmii serdes configuration" register to a magical value
>> found in:
>> https://github.com/yellowback/ubuntu-precise-armadaxp/blob/master/arch/arm/mach-armadaxp/armada_xp_family/ctrlEnv/mvCtrlEnvLib.c
>
> According to the Armada XP functional datasheet, this magical value
> 0xCC7 is the one to be used to configure a SERDES interface to use the
> "Protocol Generation Setting" SGMII. There are other magical values for
> DRSGMII, SQGMII, SATA Gen I and SATA Gen II. So you could really do:
>
> #define MVNETA_SGMII_SERDES_PROTO 0xcc7
>
ok.
>> With this change, the interrupts are working/generated and ethernet is
>> working.
>>
>> Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net•org>
>>
>> Index: linux-next/drivers/net/ethernet/marvell/mvneta.c
>> ===================================================================
>> --- linux-next.orig/drivers/net/ethernet/marvell/mvneta.c 2013-06-20 23:39:37.485391949 +0200
>> +++ linux-next/drivers/net/ethernet/marvell/mvneta.c 2013-06-20 23:39:37.481391949 +0200
>> @@ -88,6 +88,8 @@
>> #define MVNETA_TX_IN_PRGRS BIT(1)
>> #define MVNETA_TX_FIFO_EMPTY BIT(8)
>> #define MVNETA_RX_MIN_FRAME_SIZE 0x247c
>> +#define MVETH_SGMII_SERDES_CFG 0x24A0
>> +#define MVETH_SGMII_SERDES_STAT 0x24A4
>
> You are not using this last define in your patch. Please also use
> MVNETA_ prefix for those defines, like all the other ones.
>
> However, there is one thing that I am not understanding completely. The
> C code you pointed above seems to do the following:
>
> pRegAddr[3] = SGMII_SERDES_CFG_REG(sgmiiPort);
> pRegAddr[4] = SGMII_SERDES_STAT_REG(sgmiiPort);
> [..]
> pRegVal[3] = (pSerdesInfo->busSpeed & (1 << serdesLineNum)) != 0 ? 0x1547 : 0xCC7;
> pRegVal[4] = 0x7;
>
> So:
>
> 1) In some conditions, it will use the 0x1547 value in some cases, and
> 0xCC7 in the other ones. And interestingly, the datasheet doesn't
> mention what the 0x1547 magical value is.
The problem I got was that I didn't understand how to 'translate' the
(1 << serdesLineNum) part, so I removed it. Moreover, dumping the
registers when everything built-in (aka 'working'), I read a value
corresponding to the 0xcc7 case but not the other one so it seemed to me
it was safer to not use the 0x1547 case.
>
> 2) It writes 0x7 to the SGMII_SERDES_STAT_REG register, but the
> datasheet mentions this register as a read-only register.
weird. Can be remains of code for old tape outs or something wrong on
the doc, 'fixed' in some pdf about erratas.
Thanks,
Arnaud
next prev parent reply other threads:[~2013-06-24 7:44 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 22:06 [patch 0/2] Fix system hang when loading mvneta module Arnaud Patard
2013-06-20 22:06 ` [patch 1/2] Fix hang when loading the mvneta driver Arnaud Patard
2013-06-20 22:06 ` [patch 2/2] Try to fix mvneta when compiled as module Arnaud Patard
2013-06-23 8:06 ` Thomas Petazzoni
2013-06-24 7:43 ` Arnaud Patard [this message]
2013-07-15 14:34 ` [patch 0/2] Fix system hang when loading mvneta module Thomas Petazzoni
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=87txko9cn8.fsf@lebrac.rtp-net.org \
--to=arnaud.patard@rtp-net$(echo .)org \
--cc=alior@marvell$(echo .)com \
--cc=ezequiel.garcia@free-electrons$(echo .)com \
--cc=gregory.clement@free-electrons$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=thomas.petazzoni@free-electrons$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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