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[net,0/1] net: phy: Fix interrupt mask loss on resume from hibernation

Message ID 20210122143524.14516-1-laurentbadel@eaton.com
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Series net: phy: Fix interrupt mask loss on resume from hibernation | expand

Message

Badel, Laurent Jan. 22, 2021, 2:35 p.m. UTC 
Some PHYs such as SMSC LAN87xx clear the interrupt mask register on
software reset. Since mdio_bus_phy_restore() calls phy_init_hw() which
does a software reset of the PHY, these PHYs will lose their interrupt 
mask configuration on resuming from hibernation.

I initially reconfigured only the PHY interrupt mask using 
phydev->config_intr(), which worked fine with PM_DEBUG/test_resume, but
there seems to be an issue when resuming from a real hibernation, by which
the interrupt type is not set appropriately (in this case 
IRQ_TYPE_LEVEL_LOW). Calling irq_set_irq_type() directly from sysfs 
restored the PHY functionality immediately suggesting that everything is
otherwise well configured. Therefore this patch suggests freeing and
re-requesting the interrupt, to guarantee proper interrupt configuration.

Laurent Badel (1):
  net: phy: Reconfigure PHY interrupt in mdio_bus_phy_restore()

 drivers/net/phy/phy_device.c | 9 +++++++++
 1 file changed, 9 insertions(+)