linux-stable.git/drivers/net/phy/microchip.c, branch v6.15

net: phy: microchip: force IRQ polling mode for lan88xx

2025-04-22T10:57:37+00:00

With lan88xx based devices the lan78xx driver can get stuck in an
interrupt loop while bringing the device up, flooding the kernel log
with messages like the following:

lan78xx 2-3:1.0 enp1s0u3: kevent 4 may have been dropped

Removing interrupt support from the lan88xx PHY driver forces the
driver to use polling instead, which avoids the problem.

The issue has been observed with Raspberry Pi devices at least since
4.14 (see [1], bug report for their downstream kernel), as well as
with Nvidia devices [2] in 2020, where disabling interrupts was the
vendor-suggested workaround (together with the claim that phylib
changes in 4.9 made the interrupt handling in lan78xx incompatible).

Iperf reports well over 900Mbits/sec per direction with client in
--dualtest mode, so there does not seem to be a significant impact on
throughput (lan88xx device connected via switch to the peer).

[1] https://github.com/raspberrypi/linux/issues/2447
[2] https://forums.developer.nvidia.com/t/jetson-xavier-and-lan7800-problem/142134/11

Link: https://lore.kernel.org/0901d90d-3f20-4a10-b680-9c978e04ddda@lunn.ch
Fixes: 792aec47d59d ("add microchip LAN88xx phy driver")
Signed-off-by: Fiona Klute 
Cc: kernel-list@raspberrypi.com
Cc: stable@vger.kernel.org
Reviewed-by: Andrew Lunn 
Link: https://patch.msgid.link/20250416102413.30654-1-fiona.klute@gmx.de
Signed-off-by: Paolo Abeni

net: phy: Constify struct mdio_device_id

2025-01-14T23:01:32+00:00

'struct mdio_device_id' is not modified in these drivers.

Constifying these structures moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  27014	  12792	      0	  39806	   9b7e	drivers/net/phy/broadcom.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  27206	  12600	      0	  39806	   9b7e	drivers/net/phy/broadcom.o

Signed-off-by: Christophe JAILLET 
Reviewed-by: Andrew Lunn 
Link: https://patch.msgid.link/403c381b7d9156b67ad68ffc44b8eee70c5e86a9.1736691226.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jakub Kicinski

net: phy: microchip: Reset LAN88xx PHY to ensure clean link state on LAN7800/7850

2024-12-03T02:56:41+00:00

Fix outdated MII_LPA data in the LAN88xx PHY, which is used in LAN7800
and LAN7850 USB Ethernet controllers. Due to a hardware limitation, the
PHY cannot reliably update link status after parallel detection when the
link partner does not support auto-negotiation. To mitigate this, add a
PHY reset in `lan88xx_link_change_notify()` when `phydev->state` is
`PHY_NOLINK`, ensuring the PHY starts in a clean state and reports
accurate fixed link parallel detection results.

Fixes: 792aec47d59d9 ("add microchip LAN88xx phy driver")
Signed-off-by: Oleksij Rempel 
Link: https://patch.msgid.link/20241125084050.414352-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski

net: phy: microchip: lan937x: add support for 100BaseTX PHY

2024-07-09T13:12:04+00:00

Add support of 100BaseTX PHY build in to LAN9371 and LAN9372 switches.

Signed-off-by: Oleksij Rempel 
Reviewed-by: Florian Fainelli 
Reviewed-by: Michal Kubiak 
Acked-by: Arun Ramadoss 
Link: https://patch.msgid.link/20240706154201.1456098-1-o.rempel@pengutronix.de
Signed-off-by: Paolo Abeni

net: lan78xx: fix accessing the LAN7800's internal phy specific registers from the MAC driver

2023-03-03T06:21:07+00:00

Move the LAN7800 internal phy (phy ID  0x0007c132) specific register
accesses to the phy driver (microchip.c).

Fix the error reported by Enguerrand de Ribaucourt in December 2022,
"Some operations during the cable switch workaround modify the register
LAN88XX_INT_MASK of the PHY. However, this register is specific to the
LAN8835 PHY. For instance, if a DP8322I PHY is connected to the LAN7801,
that register (0x19), corresponds to the LED and MAC address
configuration, resulting in unapropriate behavior."

I did not test with the DP8322I PHY, but I tested with an EVB-LAN7800
with the internal PHY.

Fixes: 14437e3fa284 ("lan78xx: workaround of forced 100 Full/Half duplex mode error")
Signed-off-by: Yuiko Oshino 
Reviewed-by: Andrew Lunn 
Link: https://lore.kernel.org/r/20230301154307.30438-1-yuiko.oshino@microchip.com
Signed-off-by: Jakub Kicinski

net: phy: microchip: add comments for the modified LAN88xx phy ID mask.

2022-05-11T01:57:14+00:00

add comments for the updated LAN88xx phy ID mask in the previous patch.

Signed-off-by: Yuiko Oshino 
Signed-off-by: Jakub Kicinski

net: phy: microchip: update LAN88xx phy ID and phy ID mask.

2022-05-09T11:20:56+00:00

update LAN88xx phy ID and phy ID mask because the existing code conflicts with the LAN8742 phy.

The current phy IDs on the available hardware.
        LAN8742 0x0007C130, 0x0007C131
        LAN88xx 0x0007C132

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

net: phy: microchip: remove the use of .ack_interrupt()

2020-11-17T19:36:59+00:00

In preparation of removing the .ack_interrupt() callback, we must replace
its occurrences (aka phy_clear_interrupt), from the 2 places where it is
called from (phy_enable_interrupts and phy_disable_interrupts), with
equivalent functionality.

This means that clearing interrupts now becomes something that the PHY
driver is responsible of doing, before enabling interrupts and after
clearing them. Make this driver follow the new contract.

Cc: Nisar Sayed 
Cc: Yuiko Oshino 
Signed-off-by: Ioana Ciornei 
Signed-off-by: Jakub Kicinski

net: phy: microchip: implement generic .handle_interrupt() callback

2020-11-17T19:36:59+00:00

In an attempt to actually support shared IRQs in phylib, we now move the
responsibility of triggering the phylib state machine or just returning
IRQ_NONE, based on the IRQ status register, to the PHY driver. Having
3 different IRQ handling callbacks (.handle_interrupt(),
.did_interrupt() and .ack_interrupt() ) is confusing so let the PHY
driver implement directly an IRQ handler like any other device driver.
Make this driver follow the new convention.

Cc: Nisar Sayed 
Cc: Yuiko Oshino 
Signed-off-by: Ioana Ciornei 
Signed-off-by: Jakub Kicinski

net: phy: remove calls to genphy_config_init

2019-08-17T19:34:50+00:00

Supported PHY features are either auto-detected or explicitly set.
In both cases calling genphy_config_init isn't needed. All that
genphy_config_init does is removing features that are set as
supported but can't be auto-detected. Basically it duplicates the
code in genphy_read_abilities. Therefore remove such calls from
all PHY drivers.

v2:
- remove call also from new adin PHY driver
v3:
- pass NULL as config_init function pointer for dp83848

Signed-off-by: Heiner Kallweit 
Signed-off-by: David S. Miller