From: Baruch Siach <bar...@tkos.co.il>
> I'm testing kernel v5.2-rc1 on my i.MX8MQ system, SolidRun Hummingboard
> Pulse. The fec driver happens to probe before the gpio driver that we need for
> the PHY reset. So fec_reset_phy() returns -EPROBE_DEFER. This triggers the
> splat below when clk_ahb is disabled somewhere below the 'failed_reset'
> label:
>
> [ 1.267218] enet1_root_clk already disabled
> [ 1.271462] WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:924
> clk_core_disable+0xa0/0xa8
> [ 1.279396] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
> 5.2.0-rc1-00002-gb88a935c6e3f-dirty #1340
> [ 1.288105] Hardware name: SolidRun i.MX8MQ HummingBoard Pulse
> (DT)
> [ 1.294383] pstate: 60000085 (nZCv daIf -PAN -UAO)
> [ 1.299184] pc : clk_core_disable+0xa0/0xa8
> [ 1.303376] lr : clk_core_disable+0xa0/0xa8
> [ 1.307565] sp : ffff00001003bad0
> [ 1.310886] x29: ffff00001003bad0 x28: ffff0000110c4000
> [ 1.316208] x27: ffff00001099f0b0 x26: ffff8000bd9f50a8
> [ 1.321530] x25: ffff00001099dfb0 x24: ffff0000110c4990
> [ 1.326852] x23: ffff8000bd9f4810 x22: ffff8000b8820000
> [ 1.332173] x21: ffff8000b949ec00 x20: ffff8000b91d0d00
> [ 1.337495] x19: ffff8000b91d0d00 x18: 0000000000000010
> [ 1.342816] x17: 0000000000000000 x16: 0000000000000000
> [ 1.348138] x15: ffffffffffffffff x14: 0720072007200720
> [ 1.353459] x13: 0720072007200720 x12: 0720072007200720
> [ 1.358780] x11: 0720072007200720 x10: 0720072007200720
> [ 1.364101] x9 : 0720072007200720 x8 : 0720072007200720
> [ 1.369423] x7 : 000000000000009b x6 : ffff8000ba020f00
> [ 1.374744] x5 : 0000000000000000 x4 : 0000000000000000
> [ 1.380065] x3 : 00000000ffffffff x2 : ffff000011008ce0
> [ 1.385386] x1 : dc292ba4797d3600 x0 : 0000000000000000
> [ 1.390708] Call trace:
> [ 1.393162] clk_core_disable+0xa0/0xa8
> [ 1.397006] clk_core_disable_lock+0x20/0x38
> [ 1.401286] clk_disable+0x1c/0x28
> [ 1.404698] fec_probe+0x6a4/0x1248
> [ 1.408196] platform_drv_probe+0x50/0xa0
> [ 1.412214] really_probe+0xcc/0x280
> [ 1.415797] driver_probe_device+0x54/0xe8
> [ 1.419901] device_driver_attach+0x6c/0x78
> [ 1.424092] __driver_attach+0x68/0xe8
> [ 1.427851] bus_for_each_dev+0x70/0xc0
> [ 1.431695] driver_attach+0x20/0x28
> [ 1.435279] bus_add_driver+0x170/0x1d0
> [ 1.439123] driver_register+0x60/0x110
> [ 1.442967] __platform_driver_register+0x44/0x50
> [ 1.447683] fec_driver_init+0x18/0x20
> [ 1.451443] do_one_initcall+0x70/0x164
> [ 1.455288] kernel_init_freeable+0x1a0/0x234
> [ 1.459657] kernel_init+0x10/0x100
> [ 1.463156] ret_from_fork+0x10/0x18
> [ 1.466743] ---[ end trace 5e50e985bb318e6c ]---
>
> On the following probe attempt after gpio probe, fec probes successfully, and
> Ethernet is functional. So this is not a fatal error, but it is not nice.
>
> Any idea how to fix it?
Below patch can fix the issue. You can try it. I will send the patch later.
@@ -3556,7 +3555,7 @@ fec_probe(struct platform_device *pdev)
if (fep->reg_phy)
regulator_disable(fep->reg_phy);
failed_reset:
- pm_runtime_put(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
pm_runtime_disable(&pdev->dev);
failed_regulator:
clk_disable_unprepare(fep->clk_ahb);
>
> Thanks,
> baruch
>
> --
>
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