kernel.git/drivers/net/phy/phy_device.c, branch linux-5.18.y

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

2022-07-07T15:54:44Z

commit 1758bde2e4aa5ff188d53e7d9d388bbb7e12eebb upstream. 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 Signed-off-by: Greg Kroah-Hartman

net: phy: exported the genphy_read_master_slave function

2022-03-08T12:34:33Z

genphy_read_master_slave function allows to configure the master/slave for gigabit phys only. In order to use this function irrespective of speed, moved the speed check to the genphy_read_status call. Signed-off-by: Arun Ramadoss Reviewed-by: Andrew Lunn Signed-off-by: Paolo Abeni

phylib: fix potential use-after-free

2022-01-21T04:17:04Z

Commit bafbdd527d56 ("phylib: Add device reset GPIO support") added call to phy_device_reset(phydev) after the put_device() call in phy_detach(). The comment before the put_device() call says that the phydev might go away with put_device(). Fix potential use-after-free by calling phy_device_reset() before put_device(). Fixes: bafbdd527d56 ("phylib: Add device reset GPIO support") Signed-off-by: Marek Behún Reviewed-by: Andrew Lunn Link: https://lore.kernel.org/r/20220119162748.32418-1-kabel@kernel.org Signed-off-by: Jakub Kicinski

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

2021-10-14T23:50:14Z

tools/testing/selftests/net/ioam6.sh 7b1700e009cc ("selftests: net: modify IOAM tests for undef bits") bf77b1400a56 ("selftests: net: Test for the IOAM encapsulation with IPv6") Signed-off-by: Jakub Kicinski

net: phy: Do not shutdown PHYs in READY state

2021-10-09T12:47:37Z

In case a PHY device was probed thus in the PHY_READY state, but not configured and with no network device attached yet, we should not be trying to shut it down because it has been brought back into reset by phy_device_reset() towards the end of phy_probe() and anyway we have not configured the PHY yet. Fixes: e2f016cf7751 ("net: phy: add a shutdown procedure") Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller

net: phylib: ensure phy device drivers do not match by DT

2021-10-08T14:21:25Z

PHYLIB device drivers must match by either numerical PHY ID or by their .match_phy_device method. Matching by DT is not permitted. Link: https://lore.kernel.org/r/2b1dc053-8c9a-e3e4-b450-eecdfca3fe16@gmail.com Tested-by: Andrew Lunn Reviewed-by: Andrew Lunn Signed-off-by: Russell King (Oracle) Signed-off-by: David S. Miller

Revert "net: phy: Uniform PHY driver access"

2021-09-15T22:06:46Z

This reverts commit 3ac8eed62596387214869319379c1fcba264d8c6, which did more than it said on the box, and not only it replaced to_phy_driver with phydev->drv, but it also removed the "!drv" check, without actually explaining why that is fine. That patch in fact breaks suspend/resume on any system which has PHY devices with no drivers bound. The stack trace is: Unable to handle kernel NULL pointer dereference at virtual address 00000000000000e8 pc : mdio_bus_phy_suspend+0xd8/0xec lr : dpm_run_callback+0x38/0x90 Call trace: mdio_bus_phy_suspend+0xd8/0xec dpm_run_callback+0x38/0x90 __device_suspend+0x108/0x3cc dpm_suspend+0x140/0x210 dpm_suspend_start+0x7c/0xa0 suspend_devices_and_enter+0x13c/0x540 pm_suspend+0x2a4/0x330 Examples why that assumption is not fine: - There is an MDIO bus with a PHY device that doesn't have a specific PHY driver loaded, because mdiobus_register() automatically creates a PHY device for it but there is no specific PHY driver in the system. Normally under those circumstances, the generic PHY driver will be bound lazily to it (at phy_attach_direct time). But some Ethernet drivers attach to their PHY at .ndo_open time. Until then it, the to-be-driven-by-genphy PHY device will not have a driver. The blamed patch amounts to saying "you need to open all net devices before the system can suspend, to avoid the NULL pointer dereference". - There is any raw MDIO device which has 'plausible' values in the PHY ID registers 2 and 3, which is located on an MDIO bus whose driver does not set bus->phy_mask = ~0 (which prevents auto-scanning of PHY devices). An example could be a MAC's internal MDIO bus with PCS devices on it, for serial links such as SGMII. PHY devices will get created for those PCSes too, due to that MDIO bus auto-scanning, and although those PHY devices are not used, they do not bother anybody either. PCS devices are usually managed in Linux as raw MDIO devices. Nonetheless, they do not have a PHY driver, nor does anybody attempt to connect to them (because they are not a PHY), and therefore this patch breaks that. The goal itself of the patch is questionable, so I am going for a straight revert. to_phy_driver does not seem to have a need to be replaced by phydev->drv, in fact that might even trigger code paths which were not given too deep of a thought. For instance: phy_probe populates phydev->drv at the beginning, but does not clean it up on any error (including EPROBE_DEFER). So if the phydev driver requests probe deferral, phydev->drv will remain populated despite there being no driver bound. If a system suspend starts in between the initial probe deferral request and the subsequent probe retry, we will be calling the phydev->drv->suspend method, but _before_ any phydev->drv->probe call has succeeded. That is to say, if the phydev->drv is allocating any driver-private data structure in ->probe, it pretty much expects that data structure to be available in ->suspend. But it may not. That is a pretty insane environment to present to PHY drivers. In the code structure before the blamed patch, mdio_bus_phy_may_suspend would just say "no, don't suspend" to any PHY device which does not have a driver pointer _in_the_device_structure_ (not the phydev->drv). That would essentially ensure that ->suspend will never get called for a device that has not yet successfully completed probe. This is the code structure the patch is returning to, via the revert. Fixes: 3ac8eed62596 ("net: phy: Uniform PHY driver access") Signed-off-by: Vladimir Oltean Acked-by: Florian Fainelli Link: https://lore.kernel.org/r/20210914140515.2311548-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski

net: phy: Uniform PHY driver access

2021-08-20T13:31:46Z

struct phy_device contains a pointer to the PHY driver and nearly everywhere this pointer is used to access the PHY driver. Only mdio_bus_phy_may_suspend() is still using to_phy_driver() instead of the PHY driver pointer. Uniform PHY driver access by eliminating to_phy_driver() use in mdio_bus_phy_may_suspend(). Only phy_bus_match() and phy_probe() are still using to_phy_driver(), because PHY driver pointer is not available there. Signed-off-by: Gerhard Engleder Signed-off-by: David S. Miller

net: phy: Support set_loopback override

2021-08-20T13:31:46Z

phy_read_status and various other PHY functions support PHY specific overriding of driver functions by using a PHY specific pointer to the PHY driver. Add support of PHY specific override to phy_loopback too. Signed-off-by: Gerhard Engleder Signed-off-by: David S. Miller

net: phy: add API to read 802.3-c45 IDs

2021-07-20T13:55:20Z

Add API to read 802.3-c45 IDs so that C22/C45 mixed device can use C45 APIs without failing ID checks. Signed-off-by: Xu Liang Acked-by: Hauke Mehrtens Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller