linux-stable.git/drivers/net/phy/phy.c, branch v6.5.2

net: phy: Fix deadlocking in phy_error() invocation

2023-08-19T18:26:50+00:00

Since commit 91a7cda1f4b8 ("net: phy: Fix race condition on link status
change") all the phy_error() method invocations have been causing the
nested-mutex-lock deadlock because it's normally done in the PHY-driver
threaded IRQ handlers which since that change have been called with the
phydev->lock mutex held. Here is the calls thread:

IRQ: phy_interrupt()
     +-> mutex_lock(&phydev->lock); <--------------------+
         drv->handle_interrupt()                         | Deadlock due
         +-> ERROR: phy_error()                          + to the nested
                    +-> phy_process_error()              | mutex lock
                        +-> mutex_lock(&phydev->lock); <-+
                            phydev->state = PHY_ERROR;
                            mutex_unlock(&phydev->lock);
         mutex_unlock(&phydev->lock);

The problem can be easily reproduced just by calling phy_error() from any
PHY-device threaded interrupt handler. Fix it by dropping the phydev->lock
mutex lock from the phy_process_error() method and printing a nasty error
message to the system log if the mutex isn't held in the caller execution
context.

Note for the fix to work correctly in the PHY-subsystem itself the
phydev->lock mutex locking must be added to the phy_error_precise()
function.

Link: https://lore.kernel.org/netdev/20230816180944.19262-1-fancer.lancer@gmail.com
Fixes: 91a7cda1f4b8 ("net: phy: Fix race condition on link status change")
Suggested-by: Andrew Lunn 
Signed-off-by: Serge Semin 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller

net: phy: avoid kernel warning dump when stopping an errored PHY

2023-05-24T07:28:27+00:00

When taking a network interface down (or removing a SFP module) after
the PHY has encountered an error, phy_stop() complains incorrectly
that it was called from HALTED state.

The reason this is incorrect is that the network driver will have
called phy_start() when the interface was brought up, and the fact
that the PHY has a problem bears no relationship to the administrative
state of the interface. Taking the interface administratively down
(which calls phy_stop()) is always the right thing to do after a
successful phy_start() call, whether or not the PHY has encountered
an error.

Signed-off-by: Russell King (Oracle) 
Acked-by: Florian Fainelli 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2023-03-24T17:10:20+00:00

Conflicts:

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
  6e9d51b1a5cb ("net/mlx5e: Initialize link speed to zero")
  1bffcea42926 ("net/mlx5e: Add devlink hairpin queues parameters")
https://lore.kernel.org/all/20230324120623.4ebbc66f@canb.auug.org.au/
https://lore.kernel.org/all/20230321211135.47711-1-saeed@kernel.org/

Adjacent changes:

drivers/net/phy/phy.c
  323fe43cf9ae ("net: phy: Improved PHY error reporting in state machine")
  4203d84032e2 ("net: phy: Ensure state transitions are processed from phy_stop()")

Signed-off-by: Jakub Kicinski

net: phy: Improved PHY error reporting in state machine

2023-03-24T09:18:19+00:00

When the PHY library calls phy_error() something bad has happened, and
we halt the PHY state machine. Calling phy_error() from the main state
machine however is not precise enough to know whether the issue is
reading the link status or starting auto-negotiation.

Signed-off-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: phy: Ensure state transitions are processed from phy_stop()

2023-03-19T10:46:13+00:00

In the phy_disconnect() -> phy_stop() path, we will be forcibly setting
the PHY state machine to PHY_HALTED. This invalidates the old_state !=
phydev->state condition in phy_state_machine() such that we will neither
display the state change for debugging, nor will we invoke the
link_change_notify() callback.

Factor the code by introducing phy_process_state_change(), and ensure
that we process the state change from phy_stop() as well.

Fixes: 5c5f626bcace ("net: phy: improve handling link_change_notify callback")
Signed-off-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: phy: Add locks to ethtool functions

2023-02-20T10:04:22+00:00

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

Signed-off-by: Andrew Lunn 
Signed-off-by: David S. Miller

net: phy: start using genphy_c45_ethtool_get/set_eee()

2023-02-13T11:12:31+00:00

All preparations are done. Now we can start using new functions and remove
the old code.

Signed-off-by: Oleksij Rempel 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller

net: phy: migrate phy_init_eee() to genphy_c45_eee_is_active()

2023-02-13T11:12:31+00:00

Reduce code duplicated by migrating phy_init_eee() to
genphy_c45_eee_is_active().

Signed-off-by: Oleksij Rempel 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller

net: phy: export phy_check_valid() function

2023-02-13T11:12:31+00:00

This function will be needed for genphy_c45_ethtool_get_eee() provided
by next patch.

Signed-off-by: Oleksij Rempel 
Reviewed-by: Alexander Duyck 
Signed-off-by: David S. Miller

drivers/net/phy: add connection between ethtool and phylib for PLCA

2023-01-11T08:35:02+00:00

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 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller