<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/net/phy/phy.c, branch v6.3-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>net: phy: Add locks to ethtool functions</title>
<updated>2023-02-20T10:04:22+00:00</updated>
<author>
<name>Andrew Lunn</name>
<email>andrew@lunn.ch</email>
</author>
<published>2023-02-17T03:07:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2f987d486610752b364fd238fa3bb1a142d80b44'/>
<id>2f987d486610752b364fd238fa3bb1a142d80b44</id>
<content type='text'>
The phydev lock should be held while accessing members of phydev,
or calling into the driver.

Signed-off-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>
The phydev lock should be held while accessing members of phydev,
or calling into the driver.

Signed-off-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: phy: start using genphy_c45_ethtool_get/set_eee()</title>
<updated>2023-02-13T11:12:31+00:00</updated>
<author>
<name>Oleksij Rempel</name>
<email>o.rempel@pengutronix.de</email>
</author>
<published>2023-02-11T07:41:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8b68710a3121e0475b123a20c4220f66a728770e'/>
<id>8b68710a3121e0475b123a20c4220f66a728770e</id>
<content type='text'>
All preparations are done. Now we can start using new functions and remove
the old code.

Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
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>
All preparations are done. Now we can start using new functions and remove
the old code.

Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
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: phy: migrate phy_init_eee() to genphy_c45_eee_is_active()</title>
<updated>2023-02-13T11:12:31+00:00</updated>
<author>
<name>Oleksij Rempel</name>
<email>o.rempel@pengutronix.de</email>
</author>
<published>2023-02-11T07:41:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6340f9fd43d503ed5675facd5f9958a063651482'/>
<id>6340f9fd43d503ed5675facd5f9958a063651482</id>
<content type='text'>
Reduce code duplicated by migrating phy_init_eee() to
genphy_c45_eee_is_active().

Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
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>
Reduce code duplicated by migrating phy_init_eee() to
genphy_c45_eee_is_active().

Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
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: phy: export phy_check_valid() function</title>
<updated>2023-02-13T11:12:31+00:00</updated>
<author>
<name>Oleksij Rempel</name>
<email>o.rempel@pengutronix.de</email>
</author>
<published>2023-02-11T07:41:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cf9f6079696840093aa6ea3c0ee405a553afe2fb'/>
<id>cf9f6079696840093aa6ea3c0ee405a553afe2fb</id>
<content type='text'>
This function will be needed for genphy_c45_ethtool_get_eee() provided
by next patch.

Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Reviewed-by: Alexander Duyck &lt;alexanderduyck@fb.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>
This function will be needed for genphy_c45_ethtool_get_eee() provided
by next patch.

Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Reviewed-by: Alexander Duyck &lt;alexanderduyck@fb.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/net/phy: add connection between ethtool and phylib for PLCA</title>
<updated>2023-01-11T08:35:02+00:00</updated>
<author>
<name>Piergiorgio Beruto</name>
<email>piergiorgio.beruto@gmail.com</email>
</author>
<published>2023-01-09T17:00:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a23a1e57a6770a8fad1c6362dfe73bd9f27e430c'/>
<id>a23a1e57a6770a8fad1c6362dfe73bd9f27e430c</id>
<content type='text'>
This patch adds the required connection between netlink ethtool and
phylib to resolve PLCA get/set config and get status messages.

Signed-off-by: Piergiorgio Beruto &lt;piergiorgio.beruto@gmail.com&gt;
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>
This patch adds the required connection between netlink ethtool and
phylib to resolve PLCA get/set config and get status messages.

Signed-off-by: Piergiorgio Beruto &lt;piergiorgio.beruto@gmail.com&gt;
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>ethtool: linkstate: add a statistic for PHY down events</title>
<updated>2022-11-08T09:36:54+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-11-04T19:01:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9a0f830f80265bd1ef816e1541ac24bee80e9a3c'/>
<id>9a0f830f80265bd1ef816e1541ac24bee80e9a3c</id>
<content type='text'>
The previous attempt to augment carrier_down (see Link)
was not met with much enthusiasm so let's do the simple
thing of exposing what some devices already maintain.
Add a common ethtool statistic for link going down.
Currently users have to maintain per-driver mapping
to extract the right stat from the vendor-specific ethtool -S
stats. carrier_down does not fit the bill because it counts
a lot of software related false positives.

Add the statistic to the extended link state API to steer
vendors towards implementing all of it.

Implement for bnxt and all Linux-controlled PHYs. mlx5 and (possibly)
enic also have a counter for this but I leave the implementation
to their maintainers.

Link: https://lore.kernel.org/r/20220520004500.2250674-1-kuba@kernel.org
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Reviewed-by: Michael Chan &lt;michael.chan@broadcom.com&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://lore.kernel.org/r/20221104190125.684910-1-kuba@kernel.org
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The previous attempt to augment carrier_down (see Link)
was not met with much enthusiasm so let's do the simple
thing of exposing what some devices already maintain.
Add a common ethtool statistic for link going down.
Currently users have to maintain per-driver mapping
to extract the right stat from the vendor-specific ethtool -S
stats. carrier_down does not fit the bill because it counts
a lot of software related false positives.

Add the statistic to the extended link state API to steer
vendors towards implementing all of it.

Implement for bnxt and all Linux-controlled PHYs. mlx5 and (possibly)
enic also have a counter for this but I leave the implementation
to their maintainers.

Link: https://lore.kernel.org/r/20220520004500.2250674-1-kuba@kernel.org
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Reviewed-by: Michael Chan &lt;michael.chan@broadcom.com&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Link: https://lore.kernel.org/r/20221104190125.684910-1-kuba@kernel.org
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: phy: Add support for rate matching</title>
<updated>2022-09-23T10:55:35+00:00</updated>
<author>
<name>Sean Anderson</name>
<email>sean.anderson@seco.com</email>
</author>
<published>2022-09-20T22:12:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0c3e10cb44232833a50cb8e3e784c432906a60c1'/>
<id>0c3e10cb44232833a50cb8e3e784c432906a60c1</id>
<content type='text'>
This adds support for rate matching (also known as rate adaptation) to
the phy subsystem. The general idea is that the phy interface runs at
one speed, and the MAC throttles the rate at which it sends packets to
the link speed. There's a good overview of several techniques for
achieving this at [1]. This patch adds support for three: pause-frame
based (such as in Aquantia phys), CRS-based (such as in 10PASS-TS and
2BASE-TL), and open-loop-based (such as in 10GBASE-W).

This patch makes a few assumptions and a few non assumptions about the
types of rate matching available. First, it assumes that different phys
may use different forms of rate matching. Second, it assumes that phys
can use rate matching for any of their supported link speeds (e.g. if a
phy supports 10BASE-T and XGMII, then it can adapt XGMII to 10BASE-T).
Third, it does not assume that all interface modes will use the same
form of rate matching. Fourth, it does not assume that all phy devices
will support rate matching (even if some do). Relaxing or strengthening
these (non-)assumptions could result in a different API. For example, if
all interface modes were assumed to use the same form of rate matching,
then a bitmask of interface modes supportting rate matching would
suffice.

For some better visibility into the process, the current rate matching
mode is exposed as part of the ethtool ksettings. For the moment, only
read access is supported. I'm not sure what userspace might want to
configure yet (disable it altogether, disable just one mode, specify the
mode to use, etc.). For the moment, since only pause-based rate
adaptation support is added in the next few commits, rate matching can
be disabled altogether by adjusting the advertisement.

802.3 calls this feature "rate adaptation" in clause 49 (10GBASE-R) and
"rate matching" in clause 61 (10PASS-TL and 2BASE-TS). Aquantia also calls
this feature "rate adaptation". I chose "rate matching" because it is
shorter, and because Russell doesn't think "adaptation" is correct in this
context.

Signed-off-by: Sean Anderson &lt;sean.anderson@seco.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>
This adds support for rate matching (also known as rate adaptation) to
the phy subsystem. The general idea is that the phy interface runs at
one speed, and the MAC throttles the rate at which it sends packets to
the link speed. There's a good overview of several techniques for
achieving this at [1]. This patch adds support for three: pause-frame
based (such as in Aquantia phys), CRS-based (such as in 10PASS-TS and
2BASE-TL), and open-loop-based (such as in 10GBASE-W).

This patch makes a few assumptions and a few non assumptions about the
types of rate matching available. First, it assumes that different phys
may use different forms of rate matching. Second, it assumes that phys
can use rate matching for any of their supported link speeds (e.g. if a
phy supports 10BASE-T and XGMII, then it can adapt XGMII to 10BASE-T).
Third, it does not assume that all interface modes will use the same
form of rate matching. Fourth, it does not assume that all phy devices
will support rate matching (even if some do). Relaxing or strengthening
these (non-)assumptions could result in a different API. For example, if
all interface modes were assumed to use the same form of rate matching,
then a bitmask of interface modes supportting rate matching would
suffice.

For some better visibility into the process, the current rate matching
mode is exposed as part of the ethtool ksettings. For the moment, only
read access is supported. I'm not sure what userspace might want to
configure yet (disable it altogether, disable just one mode, specify the
mode to use, etc.). For the moment, since only pause-based rate
adaptation support is added in the next few commits, rate matching can
be disabled altogether by adjusting the advertisement.

802.3 calls this feature "rate adaptation" in clause 49 (10GBASE-R) and
"rate matching" in clause 61 (10PASS-TL and 2BASE-TS). Aquantia also calls
this feature "rate adaptation". I chose "rate matching" because it is
shorter, and because Russell doesn't think "adaptation" is correct in this
context.

Signed-off-by: Sean Anderson &lt;sean.anderson@seco.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: phy: Don't trigger state machine while in suspend</title>
<updated>2022-06-30T03:38:52+00:00</updated>
<author>
<name>Lukas Wunner</name>
<email>lukas@wunner.de</email>
</author>
<published>2022-06-28T10:15:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1758bde2e4aa5ff188d53e7d9d388bbb7e12eebb'/>
<id>1758bde2e4aa5ff188d53e7d9d388bbb7e12eebb</id>
<content type='text'>
Upon system sleep, mdio_bus_phy_suspend() stops the phy_state_machine(),
but subsequent interrupts may retrigger it:

They may have been left enabled to facilitate wakeup and are not
quiesced until the -&gt;suspend_noirq() phase.  Unwanted interrupts may
hence occur between mdio_bus_phy_suspend() and dpm_suspend_noirq(),
as well as between dpm_resume_noirq() and mdio_bus_phy_resume().

Retriggering the phy_state_machine() through an interrupt is not only
undesirable for the reason given in mdio_bus_phy_suspend() (freezing it
midway with phydev-&gt;lock held), but also because the PHY may be
inaccessible after it's suspended:  Accesses to USB-attached PHYs are
blocked once usb_suspend_both() clears the can_submit flag and PHYs on
PCI network cards may become inaccessible upon suspend as well.

Amend phy_interrupt() to avoid triggering the state machine if the PHY
is suspended.  Signal wakeup instead if the attached net_device or its
parent has been configured as a wakeup source.  (Those conditions are
identical to mdio_bus_phy_may_suspend().)  Postpone handling of the
interrupt until the PHY has resumed.

Before stopping the phy_state_machine() in mdio_bus_phy_suspend(),
wait for a concurrent phy_interrupt() to run to completion.  That is
necessary because phy_interrupt() may have checked the PHY's suspend
status before the system sleep transition commenced and it may thus
retrigger the state machine after it was stopped.

Likewise, after re-enabling interrupt handling in mdio_bus_phy_resume(),
wait for a concurrent phy_interrupt() to complete to ensure that
interrupts which it postponed are properly rerun.

The issue was exposed by commit 1ce8b37241ed ("usbnet: smsc95xx: Forward
PHY interrupts to PHY driver to avoid polling"), but has existed since
forever.

Fixes: 541cd3ee00a4 ("phylib: Fix deadlock on resume")
Link: https://lore.kernel.org/netdev/a5315a8a-32c2-962f-f696-de9a26d30091@samsung.com/
Reported-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Tested-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: stable@vger.kernel.org # v2.6.33+
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/b7f386d04e9b5b0e2738f0125743e30676f309ef.1656410895.git.lukas@wunner.de
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Upon system sleep, mdio_bus_phy_suspend() stops the phy_state_machine(),
but subsequent interrupts may retrigger it:

They may have been left enabled to facilitate wakeup and are not
quiesced until the -&gt;suspend_noirq() phase.  Unwanted interrupts may
hence occur between mdio_bus_phy_suspend() and dpm_suspend_noirq(),
as well as between dpm_resume_noirq() and mdio_bus_phy_resume().

Retriggering the phy_state_machine() through an interrupt is not only
undesirable for the reason given in mdio_bus_phy_suspend() (freezing it
midway with phydev-&gt;lock held), but also because the PHY may be
inaccessible after it's suspended:  Accesses to USB-attached PHYs are
blocked once usb_suspend_both() clears the can_submit flag and PHYs on
PCI network cards may become inaccessible upon suspend as well.

Amend phy_interrupt() to avoid triggering the state machine if the PHY
is suspended.  Signal wakeup instead if the attached net_device or its
parent has been configured as a wakeup source.  (Those conditions are
identical to mdio_bus_phy_may_suspend().)  Postpone handling of the
interrupt until the PHY has resumed.

Before stopping the phy_state_machine() in mdio_bus_phy_suspend(),
wait for a concurrent phy_interrupt() to run to completion.  That is
necessary because phy_interrupt() may have checked the PHY's suspend
status before the system sleep transition commenced and it may thus
retrigger the state machine after it was stopped.

Likewise, after re-enabling interrupt handling in mdio_bus_phy_resume(),
wait for a concurrent phy_interrupt() to complete to ensure that
interrupts which it postponed are properly rerun.

The issue was exposed by commit 1ce8b37241ed ("usbnet: smsc95xx: Forward
PHY interrupts to PHY driver to avoid polling"), but has existed since
forever.

Fixes: 541cd3ee00a4 ("phylib: Fix deadlock on resume")
Link: https://lore.kernel.org/netdev/a5315a8a-32c2-962f-f696-de9a26d30091@samsung.com/
Reported-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Tested-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: stable@vger.kernel.org # v2.6.33+
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/b7f386d04e9b5b0e2738f0125743e30676f309ef.1656410895.git.lukas@wunner.de
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2022-05-12T23:15:30+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-05-12T22:39:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9b19e57a3c78f1f7c08a48bafb7d84caf6e80b68'/>
<id>9b19e57a3c78f1f7c08a48bafb7d84caf6e80b68</id>
<content type='text'>
No conflicts.

Build issue in drivers/net/ethernet/sfc/ptp.c
  54fccfdd7c66 ("sfc: efx_default_channel_type APIs can be static")
  49e6123c65da ("net: sfc: fix memory leak due to ptp channel")
https://lore.kernel.org/all/20220510130556.52598fe2@canb.auug.org.au/

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No conflicts.

Build issue in drivers/net/ethernet/sfc/ptp.c
  54fccfdd7c66 ("sfc: efx_default_channel_type APIs can be static")
  49e6123c65da ("net: sfc: fix memory leak due to ptp channel")
https://lore.kernel.org/all/20220510130556.52598fe2@canb.auug.org.au/

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: phy: Fix race condition on link status change</title>
<updated>2022-05-10T00:48:17+00:00</updated>
<author>
<name>Francesco Dolcini</name>
<email>francesco.dolcini@toradex.com</email>
</author>
<published>2022-05-06T06:08:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=91a7cda1f4b8bdf770000a3b60640576dafe0cec'/>
<id>91a7cda1f4b8bdf770000a3b60640576dafe0cec</id>
<content type='text'>
This fixes the following error caused by a race condition between
phydev-&gt;adjust_link() and a MDIO transaction in the phy interrupt
handler. The issue was reproduced with the ethernet FEC driver and a
micrel KSZ9031 phy.

[  146.195696] fec 2188000.ethernet eth0: MDIO read timeout
[  146.201779] ------------[ cut here ]------------
[  146.206671] WARNING: CPU: 0 PID: 571 at drivers/net/phy/phy.c:942 phy_error+0x24/0x6c
[  146.214744] Modules linked in: bnep imx_vdoa imx_sdma evbug
[  146.220640] CPU: 0 PID: 571 Comm: irq/128-2188000 Not tainted 5.18.0-rc3-00080-gd569e86915b7 #9
[  146.229563] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[  146.236257]  unwind_backtrace from show_stack+0x10/0x14
[  146.241640]  show_stack from dump_stack_lvl+0x58/0x70
[  146.246841]  dump_stack_lvl from __warn+0xb4/0x24c
[  146.251772]  __warn from warn_slowpath_fmt+0x5c/0xd4
[  146.256873]  warn_slowpath_fmt from phy_error+0x24/0x6c
[  146.262249]  phy_error from kszphy_handle_interrupt+0x40/0x48
[  146.268159]  kszphy_handle_interrupt from irq_thread_fn+0x1c/0x78
[  146.274417]  irq_thread_fn from irq_thread+0xf0/0x1dc
[  146.279605]  irq_thread from kthread+0xe4/0x104
[  146.284267]  kthread from ret_from_fork+0x14/0x28
[  146.289164] Exception stack(0xe6fa1fb0 to 0xe6fa1ff8)
[  146.294448] 1fa0:                                     00000000 00000000 00000000 00000000
[  146.302842] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[  146.311281] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[  146.318262] irq event stamp: 12325
[  146.321780] hardirqs last  enabled at (12333): [&lt;c01984c4&gt;] __up_console_sem+0x50/0x60
[  146.330013] hardirqs last disabled at (12342): [&lt;c01984b0&gt;] __up_console_sem+0x3c/0x60
[  146.338259] softirqs last  enabled at (12324): [&lt;c01017f0&gt;] __do_softirq+0x2c0/0x624
[  146.346311] softirqs last disabled at (12319): [&lt;c01300ac&gt;] __irq_exit_rcu+0x138/0x178
[  146.354447] ---[ end trace 0000000000000000 ]---

With the FEC driver phydev-&gt;adjust_link() calls fec_enet_adjust_link()
calls fec_stop()/fec_restart() and both these function reset and
temporary disable the FEC disrupting any MII transaction that
could be happening at the same time.

fec_enet_adjust_link() and phy_read() can be running at the same time
when we have one additional interrupt before the phy_state_machine() is
able to terminate.

Thread 1 (phylib WQ)       | Thread 2 (phy interrupt)
                           |
                           | phy_interrupt()            &lt;-- PHY IRQ
                           |  handle_interrupt()
                           |   phy_read()
                           |   phy_trigger_machine()
                           |    --&gt; schedule phylib WQ
                           |
                           |
phy_state_machine()        |
 phy_check_link_status()   |
  phy_link_change()        |
   phydev-&gt;adjust_link()   |
    fec_enet_adjust_link() |
     --&gt; FEC reset         | phy_interrupt()            &lt;-- PHY IRQ
                           |  phy_read()
                           |

Fix this by acquiring the phydev lock in phy_interrupt().

Link: https://lore.kernel.org/all/20220422152612.GA510015@francesco-nb.int.toradex.com/
Fixes: c974bdbc3e77 ("net: phy: Use threaded IRQ, to allow IRQ from sleeping devices")
cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Francesco Dolcini &lt;francesco.dolcini@toradex.com&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/20220506060815.327382-1-francesco.dolcini@toradex.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This fixes the following error caused by a race condition between
phydev-&gt;adjust_link() and a MDIO transaction in the phy interrupt
handler. The issue was reproduced with the ethernet FEC driver and a
micrel KSZ9031 phy.

[  146.195696] fec 2188000.ethernet eth0: MDIO read timeout
[  146.201779] ------------[ cut here ]------------
[  146.206671] WARNING: CPU: 0 PID: 571 at drivers/net/phy/phy.c:942 phy_error+0x24/0x6c
[  146.214744] Modules linked in: bnep imx_vdoa imx_sdma evbug
[  146.220640] CPU: 0 PID: 571 Comm: irq/128-2188000 Not tainted 5.18.0-rc3-00080-gd569e86915b7 #9
[  146.229563] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[  146.236257]  unwind_backtrace from show_stack+0x10/0x14
[  146.241640]  show_stack from dump_stack_lvl+0x58/0x70
[  146.246841]  dump_stack_lvl from __warn+0xb4/0x24c
[  146.251772]  __warn from warn_slowpath_fmt+0x5c/0xd4
[  146.256873]  warn_slowpath_fmt from phy_error+0x24/0x6c
[  146.262249]  phy_error from kszphy_handle_interrupt+0x40/0x48
[  146.268159]  kszphy_handle_interrupt from irq_thread_fn+0x1c/0x78
[  146.274417]  irq_thread_fn from irq_thread+0xf0/0x1dc
[  146.279605]  irq_thread from kthread+0xe4/0x104
[  146.284267]  kthread from ret_from_fork+0x14/0x28
[  146.289164] Exception stack(0xe6fa1fb0 to 0xe6fa1ff8)
[  146.294448] 1fa0:                                     00000000 00000000 00000000 00000000
[  146.302842] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[  146.311281] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[  146.318262] irq event stamp: 12325
[  146.321780] hardirqs last  enabled at (12333): [&lt;c01984c4&gt;] __up_console_sem+0x50/0x60
[  146.330013] hardirqs last disabled at (12342): [&lt;c01984b0&gt;] __up_console_sem+0x3c/0x60
[  146.338259] softirqs last  enabled at (12324): [&lt;c01017f0&gt;] __do_softirq+0x2c0/0x624
[  146.346311] softirqs last disabled at (12319): [&lt;c01300ac&gt;] __irq_exit_rcu+0x138/0x178
[  146.354447] ---[ end trace 0000000000000000 ]---

With the FEC driver phydev-&gt;adjust_link() calls fec_enet_adjust_link()
calls fec_stop()/fec_restart() and both these function reset and
temporary disable the FEC disrupting any MII transaction that
could be happening at the same time.

fec_enet_adjust_link() and phy_read() can be running at the same time
when we have one additional interrupt before the phy_state_machine() is
able to terminate.

Thread 1 (phylib WQ)       | Thread 2 (phy interrupt)
                           |
                           | phy_interrupt()            &lt;-- PHY IRQ
                           |  handle_interrupt()
                           |   phy_read()
                           |   phy_trigger_machine()
                           |    --&gt; schedule phylib WQ
                           |
                           |
phy_state_machine()        |
 phy_check_link_status()   |
  phy_link_change()        |
   phydev-&gt;adjust_link()   |
    fec_enet_adjust_link() |
     --&gt; FEC reset         | phy_interrupt()            &lt;-- PHY IRQ
                           |  phy_read()
                           |

Fix this by acquiring the phydev lock in phy_interrupt().

Link: https://lore.kernel.org/all/20220422152612.GA510015@francesco-nb.int.toradex.com/
Fixes: c974bdbc3e77 ("net: phy: Use threaded IRQ, to allow IRQ from sleeping devices")
cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Francesco Dolcini &lt;francesco.dolcini@toradex.com&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/20220506060815.327382-1-francesco.dolcini@toradex.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
