Re: [PATCH] net: stmmac: ethtool: Fixed calltrace caused by unbalanced disable_irq_wake calls

[Andrew Lunn]

On Fri, Jan 12, 2024 at 10:12:49AM +0800, Qiang Ma wrote:
> We found the following dmesg calltrace when testing the GMAC NIC notebook:
> 
> [9.448656] ------------[ cut here ]------------
> [9.448658] Unbalanced IRQ 43 wake disable
> [9.448673] WARNING: CPU: 3 PID: 1083 at kernel/irq/manage.c:688 irq_set_irq_wake+0xe0/0x128
> [9.448717] CPU: 3 PID: 1083 Comm: ethtool Tainted: G           O      4.19 #1
> [9.448773]         ...
> [9.448774] Call Trace:
> [9.448781] [<9000000000209b5c>] show_stack+0x34/0x140
> [9.448788] [<9000000000d52700>] dump_stack+0x98/0xd0
> [9.448794] [<9000000000228610>] __warn+0xa8/0x120
> [9.448797] [<9000000000d2fb60>] report_bug+0x98/0x130
> [9.448800] [<900000000020a418>] do_bp+0x248/0x2f0
> [9.448805] [<90000000002035f4>] handle_bp_int+0x4c/0x78
> [9.448808] [<900000000029ea40>] irq_set_irq_wake+0xe0/0x128
> [9.448813] [<9000000000a96a7c>] stmmac_set_wol+0x134/0x150
> [9.448819] [<9000000000be6ed0>] dev_ethtool+0x1368/0x2440
> [9.448824] [<9000000000c08350>] dev_ioctl+0x1f8/0x3e0
> [9.448827] [<9000000000bb2a34>] sock_ioctl+0x2a4/0x450
> [9.448832] [<900000000046f044>] do_vfs_ioctl+0xa4/0x738
> [9.448834] [<900000000046f778>] ksys_ioctl+0xa0/0xe8
> [9.448837] [<900000000046f7d8>] sys_ioctl+0x18/0x28
> [9.448840] [<9000000000211ab4>] syscall_common+0x20/0x34
> [9.448842] ---[ end trace 40c18d9aec863c3e ]---
> 
> Multiple disable_irq_wake() calls will keep decreasing the IRQ
> wake_depth, When wake_depth is 0, calling disable_irq_wake() again,
> will report the above calltrace.
> 
> Due to the need to appear in pairs, we cannot call disable_irq_wake()
> without calling enable_irq_wake(). Fix this by making sure there are
> no unbalanced disable_irq_wake() calls.

Just for my understanding. You trigger this by doing lots of

ethtool -s eth42 wol g

or similar without doing a matching

ethtool -s eth42 wol d

to disable wol?

Its a bit late now, but its good to give instructions how to reproduce
the issue in the commit message.

    Andrew