net: fec: Fix division by zero
commit 7f7d6c282 (net: fec: Ensure that initialization is done prior to
request_irq()) placed fec_ptp_init() into a point that ptp clock was not
available, which causes a division by zero in fec_ptp_start_cyclecounter():
[ 17.895723] Division by zero in kernel.
[ 17.899571] Backtrace:
[ 17.902094] [<80012564>] (dump_backtrace+0x0/0x10c) from [<8056deec>]
(dump_stack+0x18/0x1c)
[ 17.910539] r6:bfba8500 r5:8075c950 r4:bfba8000 r3:bfbd0000
[ 17.916284] [<8056ded4>] (dump_stack+0x0/0x1c) from [<80012688>]
(__div0+0x18/0x20)
[ 17.923968] [<80012670>] (__div0+0x0/0x20) from [<802829c4>] (Ldiv0+0x8/0x10)
[ 17.931140] [<80398534>] (fec_ptp_start_cyclecounter+0x0/0x110) from
[<80394f64>] (fec_restart+0x6c8/0x754)
[ 17.940898] [<8039489c>] (fec_restart+0x0/0x754) from [<803969a0>]
(fec_enet_adjust_link+0xdc/0x108)
[ 17.950046] [<803968c4>] (fec_enet_adjust_link+0x0/0x108) from [<80390bc4>]
(phy_state_machine+0x178/0x534)
...
Fix this by rearraging the code so that fec_ptp_init() is called only after
the clocks have been properly acquired.
Tested on both mx53 and mx6 platforms.
Reported-by: Jim Baxter <jim_baxter@mentor.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c
index 2dbb36c..fccc3bf 100644
--- a/drivers/net/ethernet/freescale/fec.c
+++ b/drivers/net/ethernet/freescale/fec.c
@@ -1782,8 +1782,49 @@
fep->phy_interface = ret;
}
+ pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
+ if (IS_ERR(pinctrl)) {
+ ret = PTR_ERR(pinctrl);
+ goto failed_pin;
+ }
+
+ fep->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+ if (IS_ERR(fep->clk_ipg)) {
+ ret = PTR_ERR(fep->clk_ipg);
+ goto failed_clk;
+ }
+
+ fep->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
+ if (IS_ERR(fep->clk_ahb)) {
+ ret = PTR_ERR(fep->clk_ahb);
+ goto failed_clk;
+ }
+
+ fep->clk_ptp = devm_clk_get(&pdev->dev, "ptp");
fep->bufdesc_ex =
pdev->id_entry->driver_data & FEC_QUIRK_HAS_BUFDESC_EX;
+ if (IS_ERR(fep->clk_ptp)) {
+ ret = PTR_ERR(fep->clk_ptp);
+ fep->bufdesc_ex = 0;
+ }
+
+ clk_prepare_enable(fep->clk_ahb);
+ clk_prepare_enable(fep->clk_ipg);
+ if (!IS_ERR(fep->clk_ptp))
+ clk_prepare_enable(fep->clk_ptp);
+
+ reg_phy = devm_regulator_get(&pdev->dev, "phy");
+ if (!IS_ERR(reg_phy)) {
+ ret = regulator_enable(reg_phy);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Failed to enable phy regulator: %d\n", ret);
+ goto failed_regulator;
+ }
+ }
+
+ fec_reset_phy(pdev);
+
if (fep->bufdesc_ex)
fec_ptp_init(ndev, pdev);
@@ -1809,47 +1850,6 @@
}
}
- pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
- if (IS_ERR(pinctrl)) {
- ret = PTR_ERR(pinctrl);
- goto failed_pin;
- }
-
- fep->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
- if (IS_ERR(fep->clk_ipg)) {
- ret = PTR_ERR(fep->clk_ipg);
- goto failed_clk;
- }
-
- fep->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
- if (IS_ERR(fep->clk_ahb)) {
- ret = PTR_ERR(fep->clk_ahb);
- goto failed_clk;
- }
-
- fep->clk_ptp = devm_clk_get(&pdev->dev, "ptp");
- if (IS_ERR(fep->clk_ptp)) {
- ret = PTR_ERR(fep->clk_ptp);
- fep->bufdesc_ex = 0;
- }
-
- clk_prepare_enable(fep->clk_ahb);
- clk_prepare_enable(fep->clk_ipg);
- if (!IS_ERR(fep->clk_ptp))
- clk_prepare_enable(fep->clk_ptp);
-
- reg_phy = devm_regulator_get(&pdev->dev, "phy");
- if (!IS_ERR(reg_phy)) {
- ret = regulator_enable(reg_phy);
- if (ret) {
- dev_err(&pdev->dev,
- "Failed to enable phy regulator: %d\n", ret);
- goto failed_regulator;
- }
- }
-
- fec_reset_phy(pdev);
-
ret = fec_enet_mii_init(pdev);
if (ret)
goto failed_mii_init;
@@ -1866,6 +1866,13 @@
failed_register:
fec_enet_mii_remove(fep);
failed_mii_init:
+failed_init:
+ for (i = 0; i < FEC_IRQ_NUM; i++) {
+ irq = platform_get_irq(pdev, i);
+ if (irq > 0)
+ free_irq(irq, ndev);
+ }
+failed_irq:
failed_regulator:
clk_disable_unprepare(fep->clk_ahb);
clk_disable_unprepare(fep->clk_ipg);
@@ -1873,14 +1880,7 @@
clk_disable_unprepare(fep->clk_ptp);
failed_pin:
failed_clk:
- for (i = 0; i < FEC_IRQ_NUM; i++) {
- irq = platform_get_irq(pdev, i);
- if (irq > 0)
- free_irq(irq, ndev);
- }
-failed_irq:
iounmap(fep->hwp);
-failed_init:
failed_ioremap:
free_netdev(ndev);
failed_alloc_etherdev: