kernel/linux.git/drivers/net/phy/phy.c, branch v6.1.168

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

2023-03-30T10:49:04+00:00

[ Upstream commit 4203d84032e28f893594a453bd8bc9c3b15c7334 ] 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 Signed-off-by: Sasha Levin

net: phy: Add support for rate matching

2022-09-23T10:55:35+00:00

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 Signed-off-by: David S. Miller

net: phy: Don't trigger state machine while in suspend

2022-06-30T03:38:52+00:00

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 ->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->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 Tested-by: Marek Szyprowski Signed-off-by: Lukas Wunner Acked-by: Rafael J. Wysocki Cc: stable@vger.kernel.org # v2.6.33+ Reviewed-by: Andrew Lunn Link: https://lore.kernel.org/r/b7f386d04e9b5b0e2738f0125743e30676f309ef.1656410895.git.lukas@wunner.de Signed-off-by: Jakub Kicinski

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

2022-05-12T23:15:30+00:00

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

net: phy: Fix race condition on link status change

2022-05-10T00:48:17+00:00

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): [] __up_console_sem+0x50/0x60 [ 146.330013] hardirqs last disabled at (12342): [] __up_console_sem+0x3c/0x60 [ 146.338259] softirqs last enabled at (12324): [] __do_softirq+0x2c0/0x624 [ 146.346311] softirqs last disabled at (12319): [] __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: Signed-off-by: Francesco Dolcini Reviewed-by: Andrew Lunn Link: https://lore.kernel.org/r/20220506060815.327382-1-francesco.dolcini@toradex.com Signed-off-by: Jakub Kicinski

net: phy: Convert to mdiobus_c45_{read|write}

2022-05-02T11:21:38+00:00

Stop using the helpers to construct a special phy address which indicates C45. Instead use the C45 accessors, which will call the busses C45 specific read/write API. Signed-off-by: Andrew Lunn Signed-off-by: Paolo Abeni

net: phy: fix duplex out of sync problem while changing settings

2021-11-04T23:46:29+00:00

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 Tested-by: Zhang Changzhong Signed-off-by: Heiner Kallweit Link: https://lore.kernel.org/r/7b8b9456-a93f-abbc-1dc5-a2c2542f932c@gmail.com Signed-off-by: Jakub Kicinski

phy: phy_ethtool_ksettings_set: Lock the PHY while changing settings

2021-10-25T13:06:43+00:00

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 Suggested-by: Walter Stoll Tested-by: Walter Stoll Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller

phy: phy_start_aneg: Add an unlocked version

2021-10-25T13:06:43+00:00

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 Signed-off-by: David S. Miller

phy: phy_ethtool_ksettings_set: Move after phy_start_aneg

2021-10-25T13:06:43+00:00

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 Signed-off-by: David S. Miller