<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/net/dsa, branch v5.16</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>dsa: mv88e6xxx: fix debug print for SPEED_UNFORCED</title>
<updated>2021-12-16T10:57:21+00:00</updated>
<author>
<name>Andrey Eremeev</name>
<email>Axtone4all@yandex.ru</email>
</author>
<published>2021-12-15T17:30:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e08cdf63049b711099efff0811273449083bb958'/>
<id>e08cdf63049b711099efff0811273449083bb958</id>
<content type='text'>
Debug print uses invalid check to detect if speed is unforced:
(speed != SPEED_UNFORCED) should be used instead of (!speed).

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Andrey Eremeev &lt;Axtone4all@yandex.ru&gt;
Fixes: 96a2b40c7bd3 ("net: dsa: mv88e6xxx: add port's MAC speed setter")
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Debug print uses invalid check to detect if speed is unforced:
(speed != SPEED_UNFORCED) should be used instead of (!speed).

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Andrey Eremeev &lt;Axtone4all@yandex.ru&gt;
Fixes: 96a2b40c7bd3 ("net: dsa: mv88e6xxx: add port's MAC speed setter")
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: mv88e6xxx: Unforce speed &amp; duplex in mac_link_down()</title>
<updated>2021-12-13T14:40:29+00:00</updated>
<author>
<name>Marek Behún</name>
<email>kabel@kernel.org</email>
</author>
<published>2021-12-11T22:51:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9d591fc028b6bddb38c6585874f331267cbdadae'/>
<id>9d591fc028b6bddb38c6585874f331267cbdadae</id>
<content type='text'>
Commit 64d47d50be7a ("net: dsa: mv88e6xxx: configure interface settings
in mac_config") removed forcing of speed and duplex from
mv88e6xxx_mac_config(), where the link is forced down, and left it only
in mv88e6xxx_mac_link_up(), by which time link is unforced.

It seems that (at least on 88E6190) when changing cmode to 2500base-x,
if the link is not forced down, but the speed or duplex are still
forced, the forcing of new settings for speed &amp; duplex doesn't take in
mv88e6xxx_mac_link_up().

Fix this by unforcing speed &amp; duplex in mv88e6xxx_mac_link_down().

Fixes: 64d47d50be7a ("net: dsa: mv88e6xxx: configure interface settings in mac_config")
Signed-off-by: Marek Behún &lt;kabel@kernel.org&gt;
Reviewed-by: Russell King (Oracle) &lt;rmk+kernel@armlinux.org.uk&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 64d47d50be7a ("net: dsa: mv88e6xxx: configure interface settings
in mac_config") removed forcing of speed and duplex from
mv88e6xxx_mac_config(), where the link is forced down, and left it only
in mv88e6xxx_mac_link_up(), by which time link is unforced.

It seems that (at least on 88E6190) when changing cmode to 2500base-x,
if the link is not forced down, but the speed or duplex are still
forced, the forcing of new settings for speed &amp; duplex doesn't take in
mv88e6xxx_mac_link_up().

Fix this by unforcing speed &amp; duplex in mv88e6xxx_mac_link_down().

Fixes: 64d47d50be7a ("net: dsa: mv88e6xxx: configure interface settings in mac_config")
Signed-off-by: Marek Behún &lt;kabel@kernel.org&gt;
Reviewed-by: Russell King (Oracle) &lt;rmk+kernel@armlinux.org.uk&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports</title>
<updated>2021-12-09T16:48:40+00:00</updated>
<author>
<name>Russell King (Oracle)</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2021-12-09T09:26:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=04ec4e6250e5f58b525b08f3dca45c7d7427620e'/>
<id>04ec4e6250e5f58b525b08f3dca45c7d7427620e</id>
<content type='text'>
Martyn Welch reports that his CPU port is unable to link where it has
been necessary to use one of the switch ports with an internal PHY for
the CPU port. The reason behind this is the port control register is
left forcing the link down, preventing traffic flow.

This occurs because during initialisation, phylink expects the link to
be down, and DSA forces the link down by synthesising a call to the
DSA drivers phylink_mac_link_down() method, but we don't touch the
forced-link state when we later reconfigure the port.

Resolve this by also unforcing the link state when we are operating in
PHY mode and the PPU is set to poll the PHY to retrieve link status
information.

Reported-by: Martyn Welch &lt;martyn.welch@collabora.com&gt;
Tested-by: Martyn Welch &lt;martyn.welch@collabora.com&gt;
Fixes: 3be98b2d5fbc ("net: dsa: Down cpu/dsa ports phylink will control")
Cc: &lt;stable@vger.kernel.org&gt; # 5.7: 2b29cb9e3f7f: net: dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's"
Signed-off-by: Russell King (Oracle) &lt;rmk+kernel@armlinux.org.uk&gt;
Link: https://lore.kernel.org/r/E1mvFhP-00F8Zb-Ul@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Martyn Welch reports that his CPU port is unable to link where it has
been necessary to use one of the switch ports with an internal PHY for
the CPU port. The reason behind this is the port control register is
left forcing the link down, preventing traffic flow.

This occurs because during initialisation, phylink expects the link to
be down, and DSA forces the link down by synthesising a call to the
DSA drivers phylink_mac_link_down() method, but we don't touch the
forced-link state when we later reconfigure the port.

Resolve this by also unforcing the link state when we are operating in
PHY mode and the PPU is set to poll the PHY to retrieve link status
information.

Reported-by: Martyn Welch &lt;martyn.welch@collabora.com&gt;
Tested-by: Martyn Welch &lt;martyn.welch@collabora.com&gt;
Fixes: 3be98b2d5fbc ("net: dsa: Down cpu/dsa ports phylink will control")
Cc: &lt;stable@vger.kernel.org&gt; # 5.7: 2b29cb9e3f7f: net: dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's"
Signed-off-by: Russell King (Oracle) &lt;rmk+kernel@armlinux.org.uk&gt;
Link: https://lore.kernel.org/r/E1mvFhP-00F8Zb-Ul@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering</title>
<updated>2021-12-09T16:09:28+00:00</updated>
<author>
<name>José Expósito</name>
<email>jose.exposito89@gmail.com</email>
</author>
<published>2021-12-09T11:05:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e8b1d7698038e76363859fb47ae0a262080646f5'/>
<id>e8b1d7698038e76363859fb47ae0a262080646f5</id>
<content type='text'>
Avoid a memory leak if there is not a CPU port defined.

Fixes: 8d5f7954b7c8 ("net: dsa: felix: break at first CPU port during init and teardown")
Addresses-Coverity-ID: 1492897 ("Resource leak")
Addresses-Coverity-ID: 1492899 ("Resource leak")
Signed-off-by: José Expósito &lt;jose.exposito89@gmail.com&gt;
Reviewed-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://lore.kernel.org/r/20211209110538.11585-1-jose.exposito89@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Avoid a memory leak if there is not a CPU port defined.

Fixes: 8d5f7954b7c8 ("net: dsa: felix: break at first CPU port during init and teardown")
Addresses-Coverity-ID: 1492897 ("Resource leak")
Addresses-Coverity-ID: 1492899 ("Resource leak")
Signed-off-by: José Expósito &lt;jose.exposito89@gmail.com&gt;
Reviewed-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://lore.kernel.org/r/20211209110538.11585-1-jose.exposito89@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: mv88e6xxx: error handling for serdes_power functions</title>
<updated>2021-12-09T15:46:27+00:00</updated>
<author>
<name>Ameer Hamza</name>
<email>amhamza.mgc@gmail.com</email>
</author>
<published>2021-12-09T04:15:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0416e7af2369b0d12a28dea8d30b104df9a6953d'/>
<id>0416e7af2369b0d12a28dea8d30b104df9a6953d</id>
<content type='text'>
Added default case to handle undefined cmode scenario in
mv88e6393x_serdes_power() and mv88e6393x_serdes_power() methods.

Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
Fixes: 21635d9203e1c (net: dsa: mv88e6xxx: Fix application of erratum 4.8 for 88E6393X)
Reviewed-by: Marek Behún &lt;kabel@kernel.org&gt;
Signed-off-by: Ameer Hamza &lt;amhamza.mgc@gmail.com&gt;
Link: https://lore.kernel.org/r/20211209041552.9810-1-amhamza.mgc@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Added default case to handle undefined cmode scenario in
mv88e6393x_serdes_power() and mv88e6393x_serdes_power() methods.

Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
Fixes: 21635d9203e1c (net: dsa: mv88e6xxx: Fix application of erratum 4.8 for 88E6393X)
Reviewed-by: Marek Behún &lt;kabel@kernel.org&gt;
Signed-off-by: Ameer Hamza &lt;amhamza.mgc@gmail.com&gt;
Link: https://lore.kernel.org/r/20211209041552.9810-1-amhamza.mgc@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's"</title>
<updated>2021-12-08T22:35:13+00:00</updated>
<author>
<name>Russell King (Oracle)</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2021-12-07T10:32:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2b29cb9e3f7f038c7f50ad2583b47caf5cb1eaf2'/>
<id>2b29cb9e3f7f038c7f50ad2583b47caf5cb1eaf2</id>
<content type='text'>
This commit fixes a misunderstanding in commit 4a3e0aeddf09 ("net: dsa:
mv88e6xxx: don't use PHY_DETECT on internal PHY's").

For Marvell DSA switches with the PHY_DETECT bit (for non-6250 family
devices), controls whether the PPU polls the PHY to retrieve the link,
speed, duplex and pause status to update the port configuration. This
applies for both internal and external PHYs.

For some switches such as 88E6352 and 88E6390X, PHY_DETECT has an
additional function of enabling auto-media mode between the internal
PHY and SERDES blocks depending on which first gains link.

The original intention of commit 5d5b231da7ac (net: dsa: mv88e6xxx: use
PHY_DETECT in mac_link_up/mac_link_down) was to allow this bit to be
used to detect when this propagation is enabled, and allow software to
update the port configuration. This has found to be necessary for some
switches which do not automatically propagate status from the SERDES to
the port, which includes the 88E6390. However, commit 4a3e0aeddf09
("net: dsa: mv88e6xxx: don't use PHY_DETECT on internal PHY's") breaks
this assumption.

Maarten Zanders has confirmed that the issue he was addressing was for
an 88E6250 switch, which does not have a PHY_DETECT bit in bit 12, but
instead a link status bit. Therefore, mv88e6xxx_port_ppu_updates() does
not report correctly.

This patch resolves the above issues by reverting Maarten's change and
instead making mv88e6xxx_port_ppu_updates() indicate whether the port
is internal for the 88E6250 family of switches.

  Yes, you're right, I'm targeting the 6250 family. And yes, your
  suggestion would solve my case and is a better implementation for
  the other devices (as far as I can see).

Fixes: 4a3e0aeddf09 ("net: dsa: mv88e6xxx: don't use PHY_DETECT on internal PHY's")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Tested-by: Maarten Zanders &lt;maarten.zanders@mind.be&gt;
Link: https://lore.kernel.org/r/E1muXm7-00EwJB-7n@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This commit fixes a misunderstanding in commit 4a3e0aeddf09 ("net: dsa:
mv88e6xxx: don't use PHY_DETECT on internal PHY's").

For Marvell DSA switches with the PHY_DETECT bit (for non-6250 family
devices), controls whether the PPU polls the PHY to retrieve the link,
speed, duplex and pause status to update the port configuration. This
applies for both internal and external PHYs.

For some switches such as 88E6352 and 88E6390X, PHY_DETECT has an
additional function of enabling auto-media mode between the internal
PHY and SERDES blocks depending on which first gains link.

The original intention of commit 5d5b231da7ac (net: dsa: mv88e6xxx: use
PHY_DETECT in mac_link_up/mac_link_down) was to allow this bit to be
used to detect when this propagation is enabled, and allow software to
update the port configuration. This has found to be necessary for some
switches which do not automatically propagate status from the SERDES to
the port, which includes the 88E6390. However, commit 4a3e0aeddf09
("net: dsa: mv88e6xxx: don't use PHY_DETECT on internal PHY's") breaks
this assumption.

Maarten Zanders has confirmed that the issue he was addressing was for
an 88E6250 switch, which does not have a PHY_DETECT bit in bit 12, but
instead a link status bit. Therefore, mv88e6xxx_port_ppu_updates() does
not report correctly.

This patch resolves the above issues by reverting Maarten's change and
instead making mv88e6xxx_port_ppu_updates() indicate whether the port
is internal for the 88E6250 family of switches.

  Yes, you're right, I'm targeting the 6250 family. And yes, your
  suggestion would solve my case and is a better implementation for
  the other devices (as far as I can see).

Fixes: 4a3e0aeddf09 ("net: dsa: mv88e6xxx: don't use PHY_DETECT on internal PHY's")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Tested-by: Maarten Zanders &lt;maarten.zanders@mind.be&gt;
Link: https://lore.kernel.org/r/E1muXm7-00EwJB-7n@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: b53: Add SPI ID table</title>
<updated>2021-12-02T13:05:17+00:00</updated>
<author>
<name>Florian Fainelli</name>
<email>f.fainelli@gmail.com</email>
</author>
<published>2021-12-02T04:17:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=88362ebfd7fb569c78d5cb507aa9d3c8fc203839'/>
<id>88362ebfd7fb569c78d5cb507aa9d3c8fc203839</id>
<content type='text'>
Currently autoloading for SPI devices does not use the DT ID table, it
uses SPI modalises. Supporting OF modalises is going to be difficult if
not impractical, an attempt was made but has been reverted, so ensure
that module autoloading works for this driver by adding an id_table
listing the SPI IDs for everything.

Fixes: 96c8395e2166 ("spi: Revert modalias changes")
Signed-off-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently autoloading for SPI devices does not use the DT ID table, it
uses SPI modalises. Supporting OF modalises is going to be difficult if
not impractical, an attempt was made but has been reverted, so ensure
that module autoloading works for this driver by adding an id_table
listing the SPI IDs for everything.

Fixes: 96c8395e2166 ("spi: Revert modalias changes")
Signed-off-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: mv88e6xxx: Link in pcs_get_state() if AN is bypassed</title>
<updated>2021-12-01T14:39:10+00:00</updated>
<author>
<name>Marek Behún</name>
<email>kabel@kernel.org</email>
</author>
<published>2021-11-30T17:01:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ede359d8843a2779d232ed30bc36089d4b5962e4'/>
<id>ede359d8843a2779d232ed30bc36089d4b5962e4</id>
<content type='text'>
Function mv88e6xxx_serdes_pcs_get_state() currently does not report link
up if AN is enabled, Link bit is set, but Speed and Duplex Resolved bit
is not set, which testing shows is the case for when auto-negotiation
was bypassed (we have AN enabled but link partner does not).

An example of such link partner is Marvell 88X3310 PHY, when put into
the mode where host interface changes between 10gbase-r, 5gbase-r,
2500base-x and sgmii according to copper speed. The 88X3310 does not
enable AN in 2500base-x, and so SerDes on mv88e6xxx currently does not
link with it.

Fix this.

Fixes: a5a6858b793f ("net: dsa: mv88e6xxx: extend phylink to Serdes PHYs")
Signed-off-by: Marek Behún &lt;kabel@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Function mv88e6xxx_serdes_pcs_get_state() currently does not report link
up if AN is enabled, Link bit is set, but Speed and Duplex Resolved bit
is not set, which testing shows is the case for when auto-negotiation
was bypassed (we have AN enabled but link partner does not).

An example of such link partner is Marvell 88X3310 PHY, when put into
the mode where host interface changes between 10gbase-r, 5gbase-r,
2500base-x and sgmii according to copper speed. The 88X3310 does not
enable AN in 2500base-x, and so SerDes on mv88e6xxx currently does not
link with it.

Fix this.

Fixes: a5a6858b793f ("net: dsa: mv88e6xxx: extend phylink to Serdes PHYs")
Signed-off-by: Marek Behún &lt;kabel@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: mv88e6xxx: Fix inband AN for 2500base-x on 88E6393X family</title>
<updated>2021-12-01T14:39:10+00:00</updated>
<author>
<name>Marek Behún</name>
<email>kabel@kernel.org</email>
</author>
<published>2021-11-30T17:01:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=163000dbc772c1eae9bdfe7c8fe30155db1efd74'/>
<id>163000dbc772c1eae9bdfe7c8fe30155db1efd74</id>
<content type='text'>
Inband AN is broken on Amethyst in 2500base-x mode when set by standard
mechanism (via cmode).

(There probably is some weird setting done by default in the switch for
 this mode that make it cycle in some state or something, because when
 the peer is the mvneta controller, it receives link change interrupts
 every ~0.3ms, but the link is always down.)

Get around this by configuring the PCS mode to 1000base-x (where inband
AN works), and then changing the SerDes frequency while SerDes
transmitter and receiver are disabled, before enabling SerDes PHY. After
disabling SerDes PHY, change the PCS mode back to 2500base-x, to avoid
confusing the device (if we leave it at 1000base-x PCS mode but with
different frequency, and then change cmode to sgmii, the device won't
change the frequency because it thinks it already has the correct one).

The register which changes the frequency is undocumented. I discovered
it by going through all registers in the ranges 4.f000-4.f100 and
1e.8000-1e.8200 for all SerDes cmodes (sgmii, 1000base-x, 2500base-x,
5gbase-r, 10gbase-r, usxgmii) and filtering out registers that didn't
make sense (the value was the same for modes which have different
frequency). The result of this was:

    reg   sgmii 1000base-x 2500base-x 5gbase-r 10gbase-r usxgmii
  04.f002  005b       0058       0059     005c      005d    005f
  04.f076  3000       0000       1000     4000      5000    7000
  04.f07c  0950       0950       1850     0550      0150    0150
  1e.8000  0059       0059       0058     0055      0051    0051
  1e.8140  0e20       0e20       0e28     0e21      0e42    0e42

Register 04.f002 is the documented Port Operational Confiuration
register, it's last 3 bits select PCS type, so changing this register
also changes the frequency to the appropriate value.

Registers 04.f076 and 04.f07c are not writable.

Undocumented register 1e.8000 was the one: changing bits 3:0 from 9 to 8
changed SerDes frequency to 3.125 GHz, while leaving the value of PCS
mode in register 04.f002.2:0 at 1000base-x. Inband autonegotiation
started working correctly.

(I didn't try anything with register 1e.8140 since 1e.8000 solved the
 problem.)

Since I don't have documentation for this register 1e.8000.3:0, I am
using the constants without names, but my hypothesis is that this
register selects PHY frequency. If in the future I have access to an
oscilloscope able to handle these frequencies, I will try to test this
hypothesis.

Fixes: de776d0d316f ("net: dsa: mv88e6xxx: add support for mv88e6393x family")
Signed-off-by: Marek Behún &lt;kabel@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Inband AN is broken on Amethyst in 2500base-x mode when set by standard
mechanism (via cmode).

(There probably is some weird setting done by default in the switch for
 this mode that make it cycle in some state or something, because when
 the peer is the mvneta controller, it receives link change interrupts
 every ~0.3ms, but the link is always down.)

Get around this by configuring the PCS mode to 1000base-x (where inband
AN works), and then changing the SerDes frequency while SerDes
transmitter and receiver are disabled, before enabling SerDes PHY. After
disabling SerDes PHY, change the PCS mode back to 2500base-x, to avoid
confusing the device (if we leave it at 1000base-x PCS mode but with
different frequency, and then change cmode to sgmii, the device won't
change the frequency because it thinks it already has the correct one).

The register which changes the frequency is undocumented. I discovered
it by going through all registers in the ranges 4.f000-4.f100 and
1e.8000-1e.8200 for all SerDes cmodes (sgmii, 1000base-x, 2500base-x,
5gbase-r, 10gbase-r, usxgmii) and filtering out registers that didn't
make sense (the value was the same for modes which have different
frequency). The result of this was:

    reg   sgmii 1000base-x 2500base-x 5gbase-r 10gbase-r usxgmii
  04.f002  005b       0058       0059     005c      005d    005f
  04.f076  3000       0000       1000     4000      5000    7000
  04.f07c  0950       0950       1850     0550      0150    0150
  1e.8000  0059       0059       0058     0055      0051    0051
  1e.8140  0e20       0e20       0e28     0e21      0e42    0e42

Register 04.f002 is the documented Port Operational Confiuration
register, it's last 3 bits select PCS type, so changing this register
also changes the frequency to the appropriate value.

Registers 04.f076 and 04.f07c are not writable.

Undocumented register 1e.8000 was the one: changing bits 3:0 from 9 to 8
changed SerDes frequency to 3.125 GHz, while leaving the value of PCS
mode in register 04.f002.2:0 at 1000base-x. Inband autonegotiation
started working correctly.

(I didn't try anything with register 1e.8140 since 1e.8000 solved the
 problem.)

Since I don't have documentation for this register 1e.8000.3:0, I am
using the constants without names, but my hypothesis is that this
register selects PHY frequency. If in the future I have access to an
oscilloscope able to handle these frequencies, I will try to test this
hypothesis.

Fixes: de776d0d316f ("net: dsa: mv88e6xxx: add support for mv88e6393x family")
Signed-off-by: Marek Behún &lt;kabel@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: mv88e6xxx: Add fix for erratum 5.2 of 88E6393X family</title>
<updated>2021-12-01T14:39:10+00:00</updated>
<author>
<name>Marek Behún</name>
<email>kabel@kernel.org</email>
</author>
<published>2021-11-30T17:01:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=93fd8207bed80ce19aaf59932cbe1c03d418a37d'/>
<id>93fd8207bed80ce19aaf59932cbe1c03d418a37d</id>
<content type='text'>
Add fix for erratum 5.2 of the 88E6393X (Amethyst) family: for 10gbase-r
mode, some undocumented registers need to be written some special
values.

Fixes: de776d0d316f ("net: dsa: mv88e6xxx: add support for mv88e6393x family")
Signed-off-by: Marek Behún &lt;kabel@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add fix for erratum 5.2 of the 88E6393X (Amethyst) family: for 10gbase-r
mode, some undocumented registers need to be written some special
values.

Fixes: de776d0d316f ("net: dsa: mv88e6xxx: add support for mv88e6393x family")
Signed-off-by: Marek Behún &lt;kabel@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
