net: bgmac: postpone turning IRQs off to avoid SoC hangs

BugLink: https://bugs.launchpad.net/bugs/2036075

[ Upstream commit e773119 ]

Turning IRQs off is done by accessing Ethernet controller registers.
That can't be done until device's clock is enabled. It results in a SoC
hang otherwise.

This bug remained unnoticed for years as most bootloaders keep all
Ethernet interfaces turned on. It seems to only affect a niche SoC
family BCM47189. It has two Ethernet controllers but CFE bootloader uses
only the first one.

Fixes: 3432261 ("net: bgmac: Mask interrupts during probe")
Signed-off-by: Rafał Miłecki <[email protected]>
Reviewed-by: Michal Kubiak <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>

drivers/net/ethernet/broadcom/bgmac.c

@@ -1492,8 +1492,6 @@ int bgmac_enet_probe(struct bgmac *bgmac)
 
 	bgmac->in_init = true;
 
-	bgmac_chip_intrs_off(bgmac);
-
 	net_dev->irq = bgmac->irq;
 	SET_NETDEV_DEV(net_dev, bgmac->dev);
 	dev_set_drvdata(bgmac->dev, bgmac);
@@ -1511,6 +1509,8 @@ int bgmac_enet_probe(struct bgmac *bgmac)
 	 */
 	bgmac_clk_enable(bgmac, 0);
 
+	bgmac_chip_intrs_off(bgmac);
+
 	/* This seems to be fixing IRQ by assigning OOB #6 to the core */
 	if (!(bgmac->feature_flags & BGMAC_FEAT_IDM_MASK)) {
 		if (bgmac->feature_flags & BGMAC_FEAT_IRQ_ID_OOB_6)