linux-stable.git/drivers/net/phy/phy.c, branch linux-5.17.y Linux kernel stable tree net: phy: Fix race condition on link status change 2022-05-18T08:28:21+00:00 Francesco Dolcini francesco.dolcini@toradex.com 2022-05-06T06:08:15+00:00 0c29394c66330386d34c7483cd9f8412ad0347c8 commit 91a7cda1f4b8bdf770000a3b60640576dafe0cec upstream. This fixes the following error caused by a race condition between phydev->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): [<c01984c4>] __up_console_sem+0x50/0x60 [ 146.330013] hardirqs last disabled at (12342): [<c01984b0>] __up_console_sem+0x3c/0x60 [ 146.338259] softirqs last enabled at (12324): [<c01017f0>] __do_softirq+0x2c0/0x624 [ 146.346311] softirqs last disabled at (12319): [<c01300ac>] __irq_exit_rcu+0x138/0x178 [ 146.354447] ---[ end trace 0000000000000000 ]--- With the FEC driver phydev->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() <-- PHY IRQ | handle_interrupt() | phy_read() | phy_trigger_machine() | --> schedule phylib WQ | | phy_state_machine() | phy_check_link_status() | phy_link_change() | phydev->adjust_link() | fec_enet_adjust_link() | --> FEC reset | phy_interrupt() <-- 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: <stable@vger.kernel.org> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20220506060815.327382-1-francesco.dolcini@toradex.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 91a7cda1f4b8bdf770000a3b60640576dafe0cec upstream.

This fixes the following error caused by a race condition between
phydev->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): [<c01984c4>] __up_console_sem+0x50/0x60
[  146.330013] hardirqs last disabled at (12342): [<c01984b0>] __up_console_sem+0x3c/0x60
[  146.338259] softirqs last  enabled at (12324): [<c01017f0>] __do_softirq+0x2c0/0x624
[  146.346311] softirqs last disabled at (12319): [<c01300ac>] __irq_exit_rcu+0x138/0x178
[  146.354447] ---[ end trace 0000000000000000 ]---

With the FEC driver phydev->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()            <-- PHY IRQ
                           |  handle_interrupt()
                           |   phy_read()
                           |   phy_trigger_machine()
                           |    --> schedule phylib WQ
                           |
                           |
phy_state_machine()        |
 phy_check_link_status()   |
  phy_link_change()        |
   phydev->adjust_link()   |
    fec_enet_adjust_link() |
     --> FEC reset         | phy_interrupt()            <-- 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: <stable@vger.kernel.org>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220506060815.327382-1-francesco.dolcini@toradex.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: phy: fix duplex out of sync problem while changing settings 2021-11-04T23:46:29+00:00 Heiner Kallweit hkallweit1@gmail.com 2021-11-03T21:08:28+00:00 a4db9055fdb9cf607775c66d39796caf6439ec92 As reported by Zhang there's a small issue if in forced mode the duplex mode changes with the link staying up [0]. In this case the MAC isn't notified about the change. The proposed patch relies on the phylib state machine and ignores the fact that there are drivers that uses phylib but not the phylib state machine. So let's don't change the behavior for such drivers and fix it w/o re-adding state PHY_FORCING for the case that phylib state machine is used. [0] https://lore.kernel.org/netdev/a5c26ffd-4ee4-a5e6-4103-873208ce0dc5@huawei.com/T/ Fixes: 2bd229df5e2e ("net: phy: remove state PHY_FORCING") Reported-by: Zhang Changzhong <zhangchangzhong@huawei.com> Tested-by: Zhang Changzhong <zhangchangzhong@huawei.com> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Link: https://lore.kernel.org/r/7b8b9456-a93f-abbc-1dc5-a2c2542f932c@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
As reported by Zhang there's a small issue if in forced mode the duplex
mode changes with the link staying up [0]. In this case the MAC isn't
notified about the change.

The proposed patch relies on the phylib state machine and ignores the
fact that there are drivers that uses phylib but not the phylib state
machine. So let's don't change the behavior for such drivers and fix
it w/o re-adding state PHY_FORCING for the case that phylib state
machine is used.

[0] https://lore.kernel.org/netdev/a5c26ffd-4ee4-a5e6-4103-873208ce0dc5@huawei.com/T/

Fixes: 2bd229df5e2e ("net: phy: remove state PHY_FORCING")
Reported-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Tested-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/7b8b9456-a93f-abbc-1dc5-a2c2542f932c@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
phy: phy_ethtool_ksettings_set: Lock the PHY while changing settings 2021-10-25T13:06:43+00:00 Andrew Lunn andrew@lunn.ch 2021-10-24T19:48:05+00:00 af1a02aa23c37045e6adfcf074cf7dbac167a403 There is a race condition where the PHY state machine can change members of the phydev structure at the same time userspace requests a change via ethtool. To prevent this, have phy_ethtool_ksettings_set take the PHY lock. Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support") Reported-by: Walter Stoll <Walter.Stoll@duagon.com> Suggested-by: Walter Stoll <Walter.Stoll@duagon.com> Tested-by: Walter Stoll <Walter.Stoll@duagon.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> 
There is a race condition where the PHY state machine can change
members of the phydev structure at the same time userspace requests a
change via ethtool. To prevent this, have phy_ethtool_ksettings_set
take the PHY lock.

Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support")
Reported-by: Walter Stoll <Walter.Stoll@duagon.com>
Suggested-by: Walter Stoll <Walter.Stoll@duagon.com>
Tested-by: Walter Stoll <Walter.Stoll@duagon.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
phy: phy_start_aneg: Add an unlocked version 2021-10-25T13:06:43+00:00 Andrew Lunn andrew@lunn.ch 2021-10-24T19:48:04+00:00 707293a56f95f8e7e0cfae008010c7933fb68973 Split phy_start_aneg into a wrapper which takes the PHY lock, and a helper doing the real work. This will be needed when phy_ethtook_ksettings_set takes the lock. Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support") Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> 
Split phy_start_aneg into a wrapper which takes the PHY lock, and a
helper doing the real work. This will be needed when
phy_ethtook_ksettings_set takes the lock.

Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
phy: phy_ethtool_ksettings_set: Move after phy_start_aneg 2021-10-25T13:06:43+00:00 Andrew Lunn andrew@lunn.ch 2021-10-24T19:48:03+00:00 64cd92d5e8180c2ded3fdea76862de6f596ae2c9 This allows it to make use of a helper which assume the PHY is already locked. Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support") Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> 
This allows it to make use of a helper which assume the PHY is already
locked.

Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
phy: phy_ethtool_ksettings_get: Lock the phy for consistency 2021-10-25T13:06:43+00:00 Andrew Lunn andrew@lunn.ch 2021-10-24T19:48:02+00:00 c10a485c3de5ccbf1fff65a382cebcb2730c6b06 The PHY structure should be locked while copying information out if it, otherwise there is no guarantee of self consistency. Without the lock the PHY state machine could be updating the structure. Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support") Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> 
The PHY structure should be locked while copying information out if
it, otherwise there is no guarantee of self consistency. Without the
lock the PHY state machine could be updating the structure.

Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
dev_ioctl: split out ndo_eth_ioctl 2021-07-27T19:11:45+00:00 Arnd Bergmann arnd@arndb.de 2021-07-27T13:45:13+00:00 a76053707dbf0dc020a73b4d90cd952409ef3691 Most users of ndo_do_ioctl are ethernet drivers that implement the MII commands SIOCGMIIPHY/SIOCGMIIREG/SIOCSMIIREG, or hardware timestamping with SIOCSHWTSTAMP/SIOCGHWTSTAMP. Separate these from the few drivers that use ndo_do_ioctl to implement SIOCBOND, SIOCBR and SIOCWANDEV commands. This is a purely cosmetic change intended to help readers find their way through the implementation. Cc: Doug Ledford <dledford@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jay Vosburgh <j.vosburgh@gmail.com> Cc: Veaceslav Falico <vfalico@gmail.com> Cc: Andy Gospodarek <andy@greyhouse.net> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Vivien Didelot <vivien.didelot@gmail.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Vladimir Oltean <olteanv@gmail.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: linux-rdma@vger.kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Most users of ndo_do_ioctl are ethernet drivers that implement
the MII commands SIOCGMIIPHY/SIOCGMIIREG/SIOCSMIIREG, or hardware
timestamping with SIOCSHWTSTAMP/SIOCGHWTSTAMP.

Separate these from the few drivers that use ndo_do_ioctl to
implement SIOCBOND, SIOCBR and SIOCWANDEV commands.

This is a purely cosmetic change intended to help readers find
their way through the implementation.

Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Vladimir Oltean <olteanv@gmail.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: phy: fix formatting issues with braces 2021-06-16T19:34:07+00:00 Wenpeng Liang liangwenpeng@huawei.com 2021-06-16T10:01:23+00:00 169d7a402dfae45e916e9c847f089482d65ddc4f Fix following format issues: 1. open brace '{' following function definitions should go to the next line. 2. braces {} are not necessary for single line statements. 3. else should follow close brace '}'. Signed-off-by: Wenpeng Liang <liangwenpeng@huawei.com> Signed-off-by: Weihang Li <liweihang@huawei.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> 
Fix following format issues:
1. open brace '{' following function definitions should go to the next
   line.
2. braces {} are not necessary for single line statements.
3. else should follow close brace '}'.

Signed-off-by: Wenpeng Liang <liangwenpeng@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: phy: do not print dump stack if device was removed 2021-06-07T20:23:02+00:00 Oleksij Rempel o.rempel@pengutronix.de 2021-06-07T08:27:26+00:00 06edf1a940be0633499e2feea31d380375a22bd9 In case phy_state_machine() works on top of USB device, we can get -ENODEV at any point. So, be less noisy if device was removed. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net> 
In case phy_state_machine() works on top of USB device, we can get -ENODEV
at any point. So, be less noisy if device was removed.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: phy: genphy_loopback: add link speed configuration 2021-04-20T23:08:02+00:00 Oleksij Rempel o.rempel@pengutronix.de 2021-04-19T13:01:02+00:00 014068dcb5b17dae110354c4de241833124edba1 In case of loopback, in most cases we need to disable autoneg support and force some speed configuration. Otherwise, depending on currently active auto negotiated link speed, the loopback may or may not work. This patch was tested with following PHYs: TJA1102, KSZ8081, KSZ9031, AT8035, AR9331. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net> 
In case of loopback, in most cases we need to disable autoneg support
and force some speed configuration. Otherwise, depending on currently
active auto negotiated link speed, the loopback may or may not work.

This patch was tested with following PHYs: TJA1102, KSZ8081, KSZ9031,
AT8035, AR9331.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>