On Mon, 2021-11-29 at 15:16 +0100, Ferry Toth wrote:

Hi,
Op 29-11-2021 om 13:08 schreef Martyn Welch:
 

quoted

On Sat, 2021-11-27 at 18:48 +0100, Ferry Toth wrote:
 

quoted

The patch introduces a new error on each unplug:

usb 1-1: USB disconnect, device number 2
usb 1-1.1: USB disconnect, device number 3
smsc95xx 1-1.1:1.0 eth0: unregister 'smsc95xx' usb-xhci-hcd.1.auto-
1.1, 
smsc95xx USB 2.0 Ethernet
smsc95xx 1-1.1:1.0 eth0: Link is Down
smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
smsc95xx 1-1.1:1.0 eth0: Failed to read reg index 0x00000114: -19
smsc95xx 1-1.1:1.0 eth0: Error reading MII_ACCESS
smsc95xx 1-1.1:1.0 eth0: __smsc95xx_mdio_read: MII is busy
smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup

Agh! Somehow missed that. I'm looking into it...

 That would be great!
 

They appear as a result of phy_disconnect() being called in unbind()
when the hardware has already been disconnected (which is kinda likely
to physically be the case with USB devices...). The PHY is not going to
be accessible, but such calls *are* needed for instances where we are
unbinding without the device having been physically removed and want to
put the device in a suitable state. Failing with -ENODEV (as it
currently does) seems to be the right thing to do.

I wonder whether removing some of these error messages might be an
option? It appears that some of them are present in other drivers, but
I don't know whether such messages get displayed when that hardware is
unplugged too or whether I'm missing something that protects against
that.

quoted

quoted

Also as reported earlier, (only) on first plug the more worrying
but 
possibly unrelated crash still happens:
------------[ cut here ]------------
DMA-API: xhci-hcd xhci-hcd.1.auto: cacheline tracking EEXIST, 
overlapping mappings aren't supported
WARNING: CPU: 0 PID: 23 at kernel/dma/debug.c:570
add_dma_entry+0x1d9/0x270
Modules linked in: rfcomm iptable_nat bnep usb_f_uac2 u_audio 
snd_sof_nocodec usb_f_mass_storage usb_f_eem u_ether
spi_pxa2xx_platform 
dw_dmac usb_f_serial u_serial libcomposite intel_mrfld_pwrbtn 
snd_sof_pci_intel_tng pwm_lpss_pci intel_mrfld_adc pwm_lpss
snd_sof_pci 
snd_sof_intel_ipc snd_sof_intel_atom dw_dmac_pci dw_dmac_core
snd_sof
snd_sof_xtensa_dsp snd_soc_acpi spi_pxa2xx_pci brcmfmac brcmutil 
hci_uart leds_gpio btbcm ti_ads7950 industrialio_triggered_buffer
kfifo_buf tun ledtrig_timer ledtrig_heartbeat mmc_block 
extcon_intel_mrfld sdhci_pci cqhci sdhci led_class mmc_core 
intel_soc_pmic_mrfld btrfs libcrc32c xor zstd_compress zlib_deflate
raid6_pq
CPU: 0 PID: 23 Comm: kworker/0:1 Not tainted 5.15.1-edison-acpi-
standard #1
Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 
2015.01.21:18.19.48
Workqueue: usb_hub_wq hub_event
RIP: 0010:add_dma_entry+0x1d9/0x270
Code: ff 0f 84 97 00 00 00 4c 8b 67 50 4d 85 e4 75 03 4c 8b 27 e8
39
ff 
52 00 48 89 c6 4c 89 e2 48 c7 c7 f0 ab e7 a7 e8 c7 5c b5 00 <0f> 0b
48 
85 ed 0f 85 a4 b3 b5 00 8b 05 46 38 9f 01 85 c0 0f 85 df
RSP: 0000:ffffb047400cfac8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffff9e25fe217478
RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9e25fe217470
RBP: ffff9e25c12ff780 R08: ffffffffa83359a8 R09: 0000000000009ffb
R10: 00000000ffffe000 R11: 3fffffffffffffff R12: ffff9e25c8a24040
R13: 0000000000000001 R14: 0000000000000206 R15: 00000000000f8be4
FS:  0000000000000000(0000) GS:ffff9e25fe200000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f62c6d586d8 CR3: 0000000002f3c000 CR4: 00000000001006f0
Call Trace:
  dma_map_page_attrs+0xfb/0x250
  ? usb_hcd_link_urb_to_ep+0x14/0xa0
  usb_hcd_map_urb_for_dma+0x3b1/0x4e0
  usb_hcd_submit_urb+0x93/0xbb0
  ? create_prof_cpu_mask+0x20/0x20
  ? arch_stack_walk+0x73/0xf0
  ? usb_hcd_link_urb_to_ep+0x14/0xa0
  ? prepare_transfer+0xff/0x140
  usb_start_wait_urb+0x60/0x160
  usb_control_msg+0xda/0x140
  hub_ext_port_status+0x82/0x100
  hub_event+0x1b1/0x1830
  ? hub_activate+0x58c/0x860
  process_one_work+0x1d4/0x370
  worker_thread+0x48/0x3d0
  ? rescuer_thread+0x360/0x360
  kthread+0x122/0x140
  ? set_kthread_struct+0x40/0x40
  ret_from_fork+0x22/0x30
---[ end trace da6ffcd9fad23a74 ]---
DMA-API: Mapped at:
  debug_dma_map_page+0x60/0xf0
  dma_map_page_attrs+0xfb/0x250
  usb_hcd_map_urb_for_dma+0x3b1/0x4e0
  usb_hcd_submit_urb+0x93/0xbb0
  usb_start_wait_urb+0x60/0x160
usb 1-1.1: new high-speed USB device number 3 using xhci-hcd
usb 1-1.1: New USB device found, idVendor=0424, idProduct=ec00, 
bcdDevice= 2.00
usb 1-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1.1: Product: LAN9514
usb 1-1.1: Manufacturer: SMSC
usb 1-1.1: SerialNumber: 00951d0d

I'm not seeing that at all, but I've also been developing and testing
on an ARM based device that has the LAN9500A I'm using built into it.

I have also recently got a LAN9500A devkit which I've tried on my
Ryzen
laptop and that's not throwing that error either.

Martyn

Yes I am using the LAN9514 Evaluation board (EVB9514). Plugging the
board into my desktop with 5.15 Ubuntu PPA kernel I also don't see this
crash.
OTOH I'm building vanilla kernel so no idea why this happens. It might
be that I have CONFIG_DMA_API_DEBUG and Ubuntu not.
 

I suspect this is probably unrelated (directly) to the driver then.

Martyn