From b793f081674e363f71699b0b32fc9a1890e52db2 Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Mon, 6 Mar 2017 14:34:27 +0100 Subject: net: ibm: emac: fix regression caused by emac_dt_phy_probe() Julian Margetson reported a panic on his SAM460EX with Kernel 4.11-rc1: | Unable to handle kernel paging request for data at address 0x00000014 | Oops: Kernel access of bad area, sig: 11 [#1] | PREEMPT | Canyonlands | Modules linked in: | CPU: 0 PID: 1 Comm: swapper Not tainted [...] | task: ea838000 task.stack: ea836000 | NIP: c0599f5c LR: c0599dd8 CTR: 00000000 | REGS: ea837c80 TRAP: 0300 Not tainted [...] | MSR: 00029000 | CR: 24371242 XER: 20000000 | DEAR: 00000014 ESR: 00000000 | GPR00: c0599ce8 ea837d30 ea838000 c0e52dcc c0d56ffb [...] | NIP [c0599f5c] emac_probe+0xfb4/0x1304 | LR [c0599dd8] emac_probe+0xe30/0x1304 | Call Trace: | [ea837d30] [c0599ce8] emac_probe+0xd40/0x1304 (unreliable) | [ea837d80] [c0533504] platform_drv_probe+0x48/0x90 | [ea837da0] [c0531c14] driver_probe_device+0x15c/0x2c4 | [ea837dd0] [c0531e04] __driver_attach+0x88/0xb0 | ---[ end trace ... ]--- The problem is caused by emac_dt_phy_probe() returing success (0) for existing device-trees configurations that do not specify a "phy-handle" property. This caused the code to skip the existing phy probe and setup. Which led to essential phy related data-structures being uninitialized. This patch also removes the unused variable in emac_dt_phy_connect(). Fixes: a577ca6badb5261d ("net: emac: add support for device-tree based PHY discovery and setup") Reported-by: Julian Margetson Signed-off-by: Christian Lamparter Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/emac/core.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/drivers/net/ethernet/ibm/emac/core.c b/drivers/net/ethernet/ibm/emac/core.c index 275c2e2349ad..c44036d5761a 100644 --- a/drivers/net/ethernet/ibm/emac/core.c +++ b/drivers/net/ethernet/ibm/emac/core.c @@ -2589,8 +2589,6 @@ static int emac_dt_mdio_probe(struct emac_instance *dev) static int emac_dt_phy_connect(struct emac_instance *dev, struct device_node *phy_handle) { - int res; - dev->phy.def = devm_kzalloc(&dev->ofdev->dev, sizeof(*dev->phy.def), GFP_KERNEL); if (!dev->phy.def) @@ -2617,7 +2615,7 @@ static int emac_dt_phy_probe(struct emac_instance *dev) { struct device_node *np = dev->ofdev->dev.of_node; struct device_node *phy_handle; - int res = 0; + int res = 1; phy_handle = of_parse_phandle(np, "phy-handle", 0); @@ -2714,13 +2712,24 @@ static int emac_init_phy(struct emac_instance *dev) if (emac_has_feature(dev, EMAC_FTR_HAS_RGMII)) { int res = emac_dt_phy_probe(dev); - mutex_unlock(&emac_phy_map_lock); - if (!res) + switch (res) { + case 1: + /* No phy-handle property configured. + * Continue with the existing phy probe + * and setup code. + */ + break; + + case 0: + mutex_unlock(&emac_phy_map_lock); goto init_phy; - dev_err(&dev->ofdev->dev, "failed to attach dt phy (%d).\n", - res); - return res; + default: + mutex_unlock(&emac_phy_map_lock); + dev_err(&dev->ofdev->dev, "failed to attach dt phy (%d).\n", + res); + return res; + } } if (dev->phy_address != 0xffffffff) -- cgit v1.2.3