Re: [PATCH 1/1] net: fec: fix miss init spinlock
From: Dmitry Eremin-Solenikov <hidden>
Date: 2013-02-04 23:23:42
On Fri, 01 Feb 2013 16:56:26 +0800, Frank Li wrote:
quoted hunk ↗ jump to hunk
BUG: spinlock bad magic on CPU#1, swapper/0/1 lock: 0xbfae0f8c, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 Backtrace: [<80011d54>] (dump_backtrace+0x0/0x10c) from [<804e7800>] (dump_stack+0x18/0x1c) r6:bfae0000 r5:bfae0f8c r4:00000000 r3:806c1310 [<804e77e8>] (dump_stack+0x0/0x1c) from [<804e9f20>] (spin_dump+0x80/0x94) [<804e9ea0>] (spin_dump+0x0/0x94) from [<804e9f60>] (spin_bug+0x2c/0x30) r5:805f6f8c r4:bfae0f8c [<804e9f34>] (spin_bug+0x0/0x30) from [<80257984>] (do_raw_spin_lock+0x170/0x1b0 ) r5:806b4950 r4:bfae0f8c [<80257814>] (do_raw_spin_lock+0x0/0x1b0) from [<804ed15c>] (_raw_spin_lock_irqs ave+0x18/0x20) [<804ed144>] (_raw_spin_lock_irqsave+0x0/0x20) from [<8033c694>] (fec_ptp_start_ cyclecounter+0x3c/0x120) r4:bfae0f8c r3:00000002 [<8033c658>] (fec_ptp_start_cyclecounter+0x0/0x120) from [<80339e08>] (fec_resta rt+0x56c/0x5f8) r8:00000000 r7:806e6f48 r6:00000112 r5:806b4950 r4:bfae0000 [<8033989c>] (fec_restart+0x0/0x5f8) from [<8033b9e4>] (fec_probe+0x508/0xa48) Signed-off-by: Frank Li <redacted> --- drivers/net/ethernet/freescale/fec.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)diff --git a/drivers/net/ethernet/freescale/fec.cb/drivers/net/ethernet/freescale/fec.c index 69b16b9..f900ae4 100644 --- a/drivers/net/ethernet/freescale/fec.c +++ b/drivers/net/ethernet/freescale/fec.c @@ -1607,6 +1607,7 @@ static int fec_enet_init(struct net_device *ndev) } spin_lock_init(&fep->hw_lock); + spin_lock_init(&fep->tmreg_lock); fep->netdev = ndev;
Please excuse me, if I'm wrong. I would consider this as a very wrong solution: First, then the spin lock is initialised twice (first time in fec_enet_init(), second time in fec_ptp_init()). Then this patch actually hides the fact that PTP part of fec is accessed from fec_ptp_start_cyclecounter() way before than fec_ptp_init() is called to initialize PTP). In my opinion the right patch should either move fec_ptp_init() call before fec_restart(), or make fec_restart intelelctual about calling fec_ptp_init()/fec_ptp_startcyclecounter() at proper time. -- With best wishes Dmitry