net: dsa: mv88e6xxx: fix lockup on warm boot

[ Upstream commit 7756ff008400ca3c28898a7634f2227051e33beb ]

If the switch is not hardware reset on a warm boot, interrupts can be
left enabled, and possibly pending. This will cause us to enter an
infinite loop trying to service an interrupt we are unable to handle,
thereby preventing the kernel from booting.

Ensure that the global 2 interrupt sources are disabled before we claim
the parent interrupt.

Observed on the ZII development revision B and C platforms with
reworked serdes support, and using reboot -f to reboot the platform.

Fixes: e32db79381fb ("net: dsa: mv88e6xxx: Implement interrupt support.")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/dsa/mv88e6xxx/global2.c b/drivers/net/dsa/mv88e6xxx/global2.c
index bdbb72fc20ede9ffac72710c8b0b5c962c07cf4b..6240976679e1e2003f9206d84dd22534451e2a51 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/global2.c
+++ b/drivers/net/dsa/mv88e6xxx/global2.c
@@ -1083,6 +1083,13 @@ int mv88e6xxx_g2_irq_setup(struct mv88e6xxx_chip *chip)
 {
        int err, irq, virq;
 
+       chip->g2_irq.masked = ~0;
+       mv88e6xxx_reg_lock(chip);
+       err = mv88e6xxx_g2_int_mask(chip, ~chip->g2_irq.masked);
+       mv88e6xxx_reg_unlock(chip);
+       if (err)
+               return err;
+
        chip->g2_irq.domain = irq_domain_add_simple(
                chip->dev->of_node, 16, 0, &mv88e6xxx_g2_irq_domain_ops, chip);
        if (!chip->g2_irq.domain)
@@ -1092,7 +1099,6 @@ int mv88e6xxx_g2_irq_setup(struct mv88e6xxx_chip *chip)
                irq_create_mapping(chip->g2_irq.domain, irq);
 
        chip->g2_irq.chip = mv88e6xxx_g2_irq_chip;
-       chip->g2_irq.masked = ~0;
 
        chip->device_irq = irq_find_mapping(chip->g1_irq.domain,
                                            MV88E6XXX_G1_STS_IRQ_DEVICE);