RE: [PATCH RFC] ethernet: stmmac: clean up the code for release/suspend/resume function

[Joakim Zhang <qiangqing.zhang@nxp.com>]

> -----Original Message-----
> From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
> Sent: 2020年12月10日 17:03
> To: Joakim Zhang <qiangqing.zhang@nxp.com>
> Cc: peppe.cavallaro@st.com; alexandre.torgue@st.com;
> joabreu@synopsys.com; davem@davemloft.net; kuba@kernel.org;
> netdev@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>
> Subject: Re: [PATCH RFC] ethernet: stmmac: clean up the code for
> release/suspend/resume function
> > > > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > > > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > > > @@ -2908,8 +2908,7 @@ static int stmmac_release(struct net_device
> *dev)
> > > >         struct stmmac_priv *priv = netdev_priv(dev);
> > > >         u32 chan;
> > > >
> > > > -       if (device_may_wakeup(priv->device))
> > >
> > > This check is to prevent link speed down if the stmmac isn't a wakeup
> device.
> >
> > When we invoke .ndo_stop, we down the net device. Per my understanding,
> we can speed down the phy, no matter it is a wakeup device or not.
> 
> The problem is if the device can't wake up, then phy link will be turned off No
> need to speed down the phy before turning off it.

Yes, it makes sense. Thanks for your explanation.

Do you encounter dev_watchdog timeout after a few hundred times suspend/resume stress time with stmmac driver?
I am not familiar with ethernet driver now, could you give me some suggestions? This issue seems more related to stmmac core driver.

[  305.273935] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[  315.983474] ------------[ cut here ]------------
[  315.988158] NETDEV WATCHDOG: eth0 (imx-dwmac): transmit queue 0 timed out
[  315.995044] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:450 dev_watchdog+0x2fc/0x30c
[  316.003315] Modules linked in:
[  316.006389] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.0-rc6-04451-g8ff26f5af83b-dirty #55
[  316.015012] Hardware name: Freescale i.MX8DXL EVK (DT)
[  316.020158] pstate: 20000005 (nzCv daif -PAN -UAO -TCO BTYPE=--)
[  316.026178] pc : dev_watchdog+0x2fc/0x30c
[  316.030198] lr : dev_watchdog+0x2fc/0x30c
[  316.034208] sp : ffff800011c7bd90
[  316.037528] x29: ffff800011c7bd90 x28: ffff00001695b940
[  316.042852] x27: 0000000000000004 x26: ffff000016dd8480
[  316.048178] x25: 0000000000000140 x24: 00000000ffffffff
[  316.053504] x23: ffff000016dd83dc x22: 0000000000000000
[  316.058827] x21: ffff800011a76000 x20: ffff000016dd8000
[  316.064154] x19: 0000000000000000 x18: 0000000000000030
[  316.069480] x17: 0000000000000000 x16: 0000000000000000
[  316.074805] x15: ffff800011a82738 x14: ffffffffffffffff
[  316.080133] x13: ffff800011a91678 x12: 0000000000002061
[  316.085456] x11: 0000000000000acb x10: ffff800011ae9678
[  316.090781] x9 : 00000000fffff000 x8 : ffff800011a91678
[  316.096107] x7 : ffff800011ae9678 x6 : 0000000000000003
[  316.101432] x5 : 0000000000000000 x4 : 0000000000000000
[  316.106758] x3 : 0000000000000000 x2 : 0000000000000100
[  316.112081] x1 : 7290e915aa0d5b00 x0 : 0000000000000000
[  316.117409] Call trace:
[  316.119866]  dev_watchdog+0x2fc/0x30c
[  316.123542]  call_timer_fn.constprop.0+0x24/0x80
[  316.128171]  __run_timers.part.0+0x1f0/0x224
[  316.132451]  run_timer_softirq+0x3c/0x7c
[  316.136380]  efi_header_end+0x124/0x290
[  316.140227]  irq_exit+0xdc/0xfc
[  316.143371]  __handle_domain_irq+0x80/0xe0
[  316.147473]  gic_handle_irq+0xc0/0x140
[  316.151232]  el1_irq+0xbc/0x180
[  316.154379]  arch_cpu_idle+0x14/0x1c
[  316.157959]  do_idle+0x230/0x2a0
[  316.161190]  cpu_startup_entry+0x28/0x70
[  316.165116]  rest_init+0xd8/0xe8
[  316.168350]  arch_call_rest_init+0x10/0x1c
[  316.172458]  start_kernel+0x4bc/0x4f4
[  316.176121] ---[ end trace a0311227e418a672 ]---


> PS: It seems your email client isn't properly setup..
Do you mean mail timestamp?

Best Regards,
Joakim Zhang