There are two issues in rockchip_usb2phy_otg_port_init(): (1) even if devm_extcon_register_notifier() returns error, the code proceeds to the next if statement and (2) if no extcon is defined in of_node, the return value of property_enabled() is reused as the return value of the whole function. If the return value of property_enable() is nonzero, (2) results in an unexpected probe failure and kernel panic in delayed work:
Unable to handle kernel NULL pointer dereference at virtual address 00000000 Mem abort info: ESR = 0x0000000086000006 EC = 0x21: IABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault user pgtable: 4k pages, 48-bit VAs, pgdp=00000000019dc000 [0000000000000000] pgd=080000000131a003, p4d=080000000131a003, pud=080000000 Internal error: Oops: 86000006 [#1] PREEMPT SMP Modules linked in: ipv6 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.0.0-rc5 #114 Hardware name: FriendlyElec NanoPi M4 (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : 0x0 lr : call_timer_fn.constprop.0+0x24/0x80 sp : ffff80000a40ba40 x29: ffff80000a40ba40 x28: 0000000000000000 x27: ffff80000a40baf0 x26: ffff800009e779c0 x25: ffff00007fb28070 x24: ffff00007fb28028 x23: ffff80000a40baf0 x22: 0000000000000000 x21: 0000000000000101 x20: ffff0000006ad880 x19: 0000000000000000 x18: 0000000000000006 x17: ffff8000761af000 x16: ffff80000800c000 x15: 0000000000004000 x14: ffff0000006ad880 x13: 000000000000030a x12: 0000000000000000 x11: ffff8000761af000 x10: ffff80000800bf40 x9 : ffff00007fb2d038 x8 : 0000000000000001 x7 : 0000000000000009 x6 : 0000000000000240 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000200 x2 : 000000003fffffff x1 : 0000000000000000 x0 : ffff0000016c9710 Call trace: 0x0 __run_timers+0x220/0x264 run_timer_softirq+0x20/0x40 __do_softirq+0x10c/0x298 __irq_exit_rcu+0xec/0xf4 irq_exit_rcu+0x10/0x1c el1_interrupt+0x38/0x70 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x64/0x68 cpuidle_enter_state+0x130/0x2fc cpuidle_enter+0x38/0x50 do_idle+0x22c/0x2c0 cpu_startup_entry+0x24/0x30 secondary_start_kernel+0x130/0x14c __secondary_switched+0xb0/0xb4 Code: bad PC value ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Oops: Fatal exception in interrupt SMP: stopping secondary CPUs Kernel Offset: disabled CPU features: 0x4000,0820b021,00001086 Memory Limit: none ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---
Refactor the control flow to avoid both issues. Since the code below out: label does no cleanup, return error codes immediately instead of using gotos and return success at the end of the function.
Cc: stable@vger.kernel.org Fixes: 8dc60f8da22f ("phy: rockchip-inno-usb2: Sync initial otg state") Signed-off-by: Mikhail Rudenko mike.rudenko@gmail.com --- drivers/phy/rockchip/phy-rockchip-inno-usb2.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c index 0b1e9337ee8e..d31b35d55927 100644 --- a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c +++ b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c @@ -1144,8 +1144,7 @@ static int rockchip_usb2phy_otg_port_init(struct rockchip_usb2phy *rphy, rport->mode = of_usb_get_dr_mode_by_phy(child_np, -1); if (rport->mode == USB_DR_MODE_HOST || rport->mode == USB_DR_MODE_UNKNOWN) { - ret = 0; - goto out; + return 0; }
INIT_DELAYED_WORK(&rport->chg_work, rockchip_chg_detect_work); @@ -1154,7 +1153,7 @@ static int rockchip_usb2phy_otg_port_init(struct rockchip_usb2phy *rphy, ret = rockchip_usb2phy_port_irq_init(rphy, rport, child_np); if (ret) { dev_err(rphy->dev, "failed to init irq for host port\n"); - goto out; + return ret; }
if (!IS_ERR(rphy->edev)) { @@ -1162,8 +1161,10 @@ static int rockchip_usb2phy_otg_port_init(struct rockchip_usb2phy *rphy,
ret = devm_extcon_register_notifier(rphy->dev, rphy->edev, EXTCON_USB_HOST, &rport->event_nb); - if (ret) + if (ret) { dev_err(rphy->dev, "register USB HOST notifier failed\n"); + return ret; + }
if (!of_property_read_bool(rphy->dev->of_node, "extcon")) { /* do initial sync of usb state */ @@ -1172,8 +1173,7 @@ static int rockchip_usb2phy_otg_port_init(struct rockchip_usb2phy *rphy, } }
-out: - return ret; + return 0; }
static int rockchip_usb2phy_probe(struct platform_device *pdev)