From: Greg Ungerer <gerg@linux-m68k.org>
To: Andy Duan <fugang.duan@nxp.com>, Andrew Lunn <andrew@lunn.ch>,
Dave Karr <dkarr@vyex.com>,
Clemens Gruber <clemens.gruber@pqgruber.com>
Cc: Chris Heally <cphealy@gmail.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [EXT] Re: [PATCH] net: ethernet: fec: Replace interrupt driven MDIO with polled IO
Date: Tue, 27 Oct 2020 10:17:30 +1000 [thread overview]
Message-ID: <a1f62ee2-3013-50fe-4069-e63f87a984ce@linux-m68k.org> (raw)
In-Reply-To: <AM8PR04MB731512CC1B16C307C4543B90FF1D0@AM8PR04MB7315.eurprd04.prod.outlook.com>
Hi Andy,
On 22/10/20 7:04 pm, Andy Duan wrote:
> From: Greg Ungerer <gerg@linux-m68k.org> Sent: Thursday, October 22, 2020 9:14 AM
>> Hi Andrew,
>>
>> On 21/10/20 11:37 pm, Andrew Lunn wrote:
>>>> + if (fep->quirks & FEC_QUIRK_CLEAR_SETUP_MII) {
>>>> + /* Clear MMFR to avoid to generate MII event by writing
>> MSCR.
>>>> + * MII event generation condition:
>>>> + * - writing MSCR:
>>>> + * - mmfr[31:0]_not_zero & mscr[7:0]_is_zero &
>>>> + * mscr_reg_data_in[7:0] != 0
>>>> + * - writing MMFR:
>>>> + * - mscr[7:0]_not_zero
>>>> + */
>>>> + writel(0, fep->hwp + FEC_MII_DATA);
>>>> + }
>>>
>>> Hi Greg
>>>
>>> The last time we discussed this, we decided that if you cannot do the
>>> quirk, you need to wait around for an MDIO interrupt, e.g. call
>>> fec_enet_mdio_wait() after setting FEC_MII_SPEED register.
>>>
>>>>
>>>> writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);
>>
>> The code following this is:
>>
>> writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);
>>
>> /* Clear any pending transaction complete indication */
>> writel(FEC_ENET_MII, fep->hwp + FEC_IEVENT);
>>
>>
>> So this is forcing a clear of the event here. Is that not good enough?
>>
>> For me on my ColdFire test target I always get a timeout if I wait for a
>> FEC_IEVENT after the FEC_MII_SPEED write.
>>
>> Regards
>> Greg
>
> Dave Karr's last patch can fix the issue, but it may introduce 30ms delay during boot.
> Greg's patch is to add quirk flag to distinguish platform before clearing mmfr operation,
> which also can fix the issue.
Do you mean that we can use either fix - and that is ok for all hardware
types?
Regards
Greg
next prev parent reply other threads:[~2020-10-27 0:17 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-20 2:14 [PATCH] net: ethernet: fec: Replace interrupt driven MDIO with polled IO Greg Ungerer
2020-10-20 2:40 ` Andrew Lunn
2020-10-20 3:02 ` [EXT] " Andy Duan
2020-10-20 13:06 ` Chris Healy
2020-10-20 13:52 ` Andy Duan
2020-10-20 13:08 ` Andrew Lunn
2020-10-21 1:51 ` Greg Ungerer
2020-10-21 2:19 ` [EXT] " Andy Duan
2020-10-21 2:37 ` Greg Ungerer
2020-10-21 13:37 ` Andrew Lunn
2020-10-22 1:14 ` Greg Ungerer
2020-10-22 2:39 ` [EXT] " Andy Duan
2020-10-22 9:04 ` Andy Duan
2020-10-27 0:17 ` Greg Ungerer [this message]
2020-10-27 1:33 ` Andy Duan
-- strict thread matches above, loose matches on Subject: below --
2020-04-14 0:45 Andrew Lunn
2020-04-27 15:19 ` Leonard Crestez
2020-04-27 16:46 ` Andrew Lunn
2020-04-27 17:48 ` [EXT] " Andy Duan
2020-04-27 20:00 ` Leonard Crestez
2020-04-27 20:13 ` Andrew Lunn
2020-04-28 7:50 ` [EXT] " Andy Duan
2020-04-28 13:34 ` Andrew Lunn
2020-04-28 13:50 ` Andy Duan
2020-04-28 14:29 ` Andrew Lunn
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