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From: Saravana Kannan <saravanak@google.com>
To: Vladimir Oltean <olteanv@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Len Brown <lenb@kernel.org>,
	Alvin Sipraga <ALSI@bang-olufsen.dk>,
	kernel-team@android.com, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org, linux-acpi@vger.kernel.org
Subject: Re: [PATCH v1 1/2] driver core: fw_devlink: Add support for FWNODE_FLAG_BROKEN_PARENT
Date: Wed, 29 Sep 2021 22:33:16 -0700	[thread overview]
Message-ID: <CAGETcx8MXzFhhxom3u2MXw8XA-uUtm9XGEbYNobfr+Ptq5+fVQ@mail.gmail.com> (raw)
In-Reply-To: <20210831231804.zozyenear45ljemd@skbuf>

On Tue, Aug 31, 2021 at 4:18 PM Vladimir Oltean <olteanv@gmail.com> wrote:
>
> On Wed, Sep 01, 2021 at 01:02:09AM +0200, Andrew Lunn wrote:
> > Rev B is interesting because switch0 and switch1 got genphy, while
> > switch2 got the correct Marvell PHY driver. switch2 PHYs don't have
> > interrupt properties, so don't loop back to their parent device.
>
> This is interesting and not what I really expected to happen. It goes to
> show that we really need more time to understand all the subtleties of
> device dependencies before jumping on patching stuff.
>
> In case the DSA tree contains more than one switch, different things
> will happen in dsa_register_switch().
> The tree itself is only initialized when the last switch calls
> dsa_register_switch(). All the other switches just mark themselves as
> present and exit probing early. See this piece of code in dsa_tree_setup:
>
>         complete = dsa_tree_setup_routing_table(dst);
>         if (!complete)
>                 return 0;

Hi Vladimir,

Can you point me to an example dts file that has a DSA tree with more
than one switch and also point me to the switches that form the tree?

I'm working on a RFC series that tries to improve some stuff and
having an example DTS to look at would help.

Thanks,
Saravana

>
> So it should be a general property of cross-chip DSA trees that all
> switches except the last one will have the specific PHY driver probed
> properly, and not the genphy.
>
> Because all (N - 1) switches of a tree exit early in dsa_register_switch,
> they have successfully probed by the time the last switch brings up the
> tree, and brings up the PHYs on behalf of every other switch.
>
> The last switch can connect to the PHY on behalf of the other switches
> past their probe ending, and those PHYs should not defer probing because
> their supplier is now probed. It is only that the last switch cannot
> connect to the PHYs of its own ports.
>
> So if this does not work (you say that there are 2 switches that use
> genphy) I suspect there are also other bugs involved.

  parent reply	other threads:[~2021-09-30  5:33 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-26  7:45 [PATCH v1 0/2] Fix rtl8366rb issues with fw_devlink=on Saravana Kannan
2021-08-26  7:45 ` [PATCH v1 1/2] driver core: fw_devlink: Add support for FWNODE_FLAG_BROKEN_PARENT Saravana Kannan
2021-08-26 13:13   ` Andrew Lunn
2021-08-26 19:56     ` Saravana Kannan
2021-08-26 20:53       ` Andrew Lunn
2021-08-26 23:44         ` Saravana Kannan
2021-08-27  1:23           ` Andrew Lunn
2021-08-27  4:02             ` Saravana Kannan
2021-08-27 13:44               ` Andrew Lunn
2021-08-27 18:06                 ` Saravana Kannan
2021-08-27 20:11                   ` Andrew Lunn
2021-08-27 21:33                     ` Saravana Kannan
2021-08-28 17:01                       ` Andrew Lunn
2021-08-30 19:03                         ` Saravana Kannan
2021-08-31 13:16                           ` Andrew Lunn
2021-08-31 19:26                             ` Saravana Kannan
2021-08-31 22:05                               ` Andrew Lunn
2021-08-31 22:18                                 ` Saravana Kannan
2021-08-31 23:02                                   ` Andrew Lunn
2021-08-31 23:18                                     ` Vladimir Oltean
2021-08-31 23:27                                       ` Andrew Lunn
2021-09-01  1:28                                       ` Vladimir Oltean
2021-09-01  1:38                                         ` Vladimir Oltean
2021-09-01  2:19                                           ` Saravana Kannan
2021-09-01  9:02                                             ` Vladimir Oltean
2021-09-01 22:57                                               ` Saravana Kannan
2021-09-01  2:00                                       ` Saravana Kannan
2021-09-01  8:46                                         ` Vladimir Oltean
2021-09-01 22:53                                           ` Saravana Kannan
2021-09-02 17:41                                           ` Andrew Lunn
2021-09-02 17:58                                             ` Saravana Kannan
2021-09-30  5:33                                       ` Saravana Kannan [this message]
2021-09-30 13:15                                         ` Andrew Lunn
2021-09-30 13:43                                         ` Vladimir Oltean
2021-09-30 14:00                                           ` Andrew Lunn
2021-09-30 17:31                                             ` Saravana Kannan
2021-09-30 19:38                                               ` Andrew Lunn
2021-09-30 19:48                                                 ` Saravana Kannan
2021-09-30 20:06                                                   ` Florian Fainelli
2021-09-30 20:14                                                     ` Saravana Kannan
2021-09-30 21:16                                                       ` Florian Fainelli
2021-09-30 20:22                                                     ` Andrew Lunn
2021-09-01  1:46                                     ` Saravana Kannan
2021-08-31 23:18                                   ` Andrew Lunn
2021-09-08 18:35                             ` Saravana Kannan
2021-09-09  1:39                           ` Andrew Lunn
2021-09-09  3:21                             ` Saravana Kannan
2021-09-09 10:38                               ` Vladimir Oltean
2021-09-09 15:00                               ` Andrew Lunn
2021-09-09 16:56                             ` Florian Fainelli
2021-08-26  7:45 ` [PATCH v1 2/2] net: dsa: rtl8366rb: Quick fix to work with fw_devlink=on Saravana Kannan
2021-08-26  7:55   ` Greg Kroah-Hartman
2021-08-26 11:25   ` Florian Fainelli
2021-08-26 17:29     ` Saravana Kannan
2021-08-26 11:29   ` Alvin Šipraga
2021-08-26 17:26     ` Saravana Kannan
2021-08-26 18:04       ` Alvin Šipraga

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