Re: [PATCH net v5 1/4] net: ethernet: oa_tc6: Interrupt is active low, level triggered.

[Parthiban.Veerasooran]

Hi Selvamani,

On 23/06/26 11:18 am, Selvamani Rajagopal wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
>> -----Original Message-----
>> From: Parthiban.Veerasooran@xxxxxxxxxxxxx <Parthiban.Veerasooran@xxxxxxxxxxxxx>
>> Subject: Re: [PATCH net v5 1/4] net: ethernet: oa_tc6: Interrupt is active low, level
>> triggered.
>>
>>
>> I will find some time this week to test and share my feedback. In the
>> meantime, would it be possible for you to test using two instances (Test
>> Case 2)? I did not encounter many issues when testing with a single
>> instance.
>>
>> I believe that testing with two instances increases the likelihood of
>> reproducing the issue in your setup as well.
> 
> Parthiban,
> 
> Thanks.
> 
> Our EVB design allows only one board to be connected to one Raspberry Pi.
> So, I don't think I can have a setup like yours. We did test with three Raspberry Pi boards with
> multi-drop connection. Couldn't see your "NULL pointer" crash. Will keep trying though.
Thank you for the update. So it seems you can't connect two of your 
MAC-PHYs in one RPI 4? RPI 4 can support two SPI devices (MAC-PHYs).

https://patchwork.kernel.org/project/netdevbpf/list/?series=1114495&state=%2A&archive=both

https://patchwork.kernel.org/project/netdevbpf/patch/20260621-fix-race-condition-and-crash-v1-1-87e290d9357f@xxxxxxxxxx/

https://patchwork.kernel.org/project/netdevbpf/patch/20260621-fix-race-condition-and-crash-v1-2-87e290d9357f@xxxxxxxxxx/

With your above patches, I did a quick test (Test case 2) with two 
Microchip MAC-PHYs and faced a similar issue reported before. Sharing 
the dmesg crash log for your reference.

[ 2863.182105] eth1: Receive buffer overflow error
[ 2863.199905] eth1: Receive buffer overflow error
[ 2867.669312] Unable to handle kernel NULL pointer dereference at 
virtual address 00000000000000b8
[ 2867.677658] Mem abort info:
[ 2867.680474]   ESR = 0x0000000096000005
[ 2867.684258]   EC = 0x25: DABT (current EL), IL = 32 bits
[ 2867.689630]   SET = 0, FnV = 0
[ 2867.692717]   EA = 0, S1PTW = 0
[ 2867.695888]   FSC = 0x05: level 1 translation fault
[ 2867.700825] Data abort info:
[ 2867.703726]   ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
[ 2867.709303]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 2867.714399]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 2867.719773] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000113c2e000
[ 2867.726296] [00000000000000b8] pgd=0000000000000000, 
p4d=0000000000000000, pud=0000000000000000
[ 2867.735109] Internal error: Oops: 0000000096000005 [#1]  SMP
[ 2867.740830] Modules linked in: lan865x_t1s(O) microchip_t1s(O) sch_fq 
snd_seq_dummy snd_hrtimer snd_seq snd_seq_device rfcomm algif_hash 
aes_neon_bs algif_skcipher af_alg bnep binfmt_misc brcmfmac_cyw brcmfmac 
hci_uart brcmutil btbcm bluetooth vc4 cfg80211 snd_soc_hdmi_codec 
drm_exec ecdh_generic ecc drm_display_helper cec rfkill bcm2835_codec(C) 
drm_dma_helper v3d rpi_hevc_dec drm_client_lib bcm2835_v4l2(C) gpu_sched 
drm_shmem_helper crc_ccitt bcm2835_isp snd_soc_core drm_kms_helper 
bcm2835_mmal_vchiq v4l2_mem2mem vc_sm_cma videobuf2_vmalloc 
videobuf2_dma_contig raspberrypi_hwmon videobuf2_memops snd_compress 
snd_bcm2835(C) videobuf2_v4l2 snd_pcm_dmaengine i2c_brcmstb snd_pcm 
snd_timer videodev videobuf2_common snd mc raspberrypi_gpiomem 
spi_bcm2835 gpio_fan nvmem_rmem sch_fq_codel i2c_dev zram lz4_compress 
drm fuse drm_panel_orientation_quirks backlight nfnetlink [last 
unloaded: microchip_t1s(O)]
[ 2867.821558] CPU: 3 UID: 0 PID: 2808 Comm: irq/59-spi0.0 Tainted: G 
      C O        7.1.0-rc7-v8+ #2 PREEMPT
[ 2867.831779] Tainted: [C]=CRAP, [O]=OOT_MODULE
[ 2867.836183] Hardware name: Raspberry Pi 4 Model B Rev 1.4 (DT)
[ 2867.842088] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS 
BTYPE=--)
[ 2867.849138] pc : oa_tc6_update_rx_skb+0x2c/0xa8 [lan865x_t1s]
[ 2867.854955] lr : oa_tc6_macphy_threaded_irq+0x430/0x870 [lan865x_t1s]
[ 2867.861476] sp : ffffffc083dbbd20
[ 2867.864825] x29: ffffffc083dbbd20 x28: 000000003e002020 x27: 
ffffffed1cf609c8
[ 2867.872051] x26: 0000000000000000 x25: 0000000000000001 x24: 
ffffff8040796480
[ 2867.879277] x23: 000000002020003e x22: 0000000000000000 x21: 
0000000000000040
[ 2867.886504] x20: ffffff804a479080 x19: ffffff8040796480 x18: 
00000000000982f8
[ 2867.893731] x17: ffffff80482d6500 x16: ffffffed1d87b6b0 x15: 
ffffff8041a43c00
[ 2867.900957] x14: 0000000000000016 x13: 0000073d6a5d38dc x12: 
00000000001d4ebe
[ 2867.908184] x11: 00000000000000c0 x10: 0000000000001ae0 x9 : 
ffffffecc9c959e8
[ 2867.915410] x8 : ffffff804f1e5a40 x7 : 0000000000000002 x6 : 
ffffffffffffffff
[ 2867.922636] x5 : ffffffed1e59d000 x4 : 0000000000000002 x3 : 
0000000000000000
[ 2867.929863] x2 : 0000000000000040 x1 : ffffff804a479080 x0 : 
0000000000000000
[ 2867.937090] Call trace:
[ 2867.939558]  oa_tc6_update_rx_skb+0x2c/0xa8 [lan865x_t1s] (P)
[ 2867.945375]  oa_tc6_macphy_threaded_irq+0x430/0x870 [lan865x_t1s]
[ 2867.951543]  irq_thread_fn+0x34/0xc0
[ 2867.955156]  irq_thread+0x1a8/0x308
[ 2867.958680]  kthread+0x138/0x150
[ 2867.961942]  ret_from_fork+0x10/0x20
[ 2867.965558] Code: aa0103f4 f90013f5 12001c55 f9403800 (29570403)
[ 2867.971727] ---[ end trace 0000000000000000 ]---
[ 2867.976443] genirq: exiting task "irq/59-spi0.0" (2808) is an active 
IRQ thread (irq 59)
[ 2868.094789] irq 59: nobody cared (try booting with the "irqpoll" option)
[ 2868.101000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G      D  C 
O        7.1.0-rc7-v8+ #2 PREEMPT
[ 2868.101007] Tainted: [D]=DIE, [C]=CRAP, [O]=OOT_MODULE
[ 2868.101009] Hardware name: Raspberry Pi 4 Model B Rev 1.4 (DT)
[ 2868.101011] Call trace:
[ 2868.101013]  show_stack+0x20/0x38 (C)
[ 2868.101027]  dump_stack_lvl+0x60/0x80
[ 2868.101033]  dump_stack+0x18/0x24
[ 2868.101038]  __report_bad_irq+0x54/0xf0
[ 2868.101043]  note_interrupt+0x344/0x398
[ 2868.101048]  handle_irq_event+0xa4/0x110
[ 2868.101051]  handle_level_irq+0xe0/0x178
[ 2868.101056]  handle_irq_desc+0x3c/0x68
[ 2868.101061]  generic_handle_domain_irq+0x20/0x40
[ 2868.101067]  bcm2835_gpio_irq_handle_bank+0x180/0x1c8
[ 2868.101074]  bcm2835_gpio_irq_handler+0x88/0x188
[ 2868.101080]  handle_irq_desc+0x3c/0x68
[ 2868.101085]  generic_handle_domain_irq+0x20/0x40
[ 2868.101091]  gic_handle_irq+0x4c/0xe0
[ 2868.101094]  call_on_irq_stack+0x30/0x88
[ 2868.101099]  do_interrupt_handler+0x88/0x98
[ 2868.101102]  el1_interrupt+0x3c/0x60
[ 2868.101108]  el1h_64_irq_handler+0x18/0x30
[ 2868.101113]  el1h_64_irq+0x6c/0x70
[ 2868.101116]  default_idle_call+0x34/0x1a0 (P)
[ 2868.101123]  do_idle+0x260/0x2a0
[ 2868.101128]  cpu_startup_entry+0x3c/0x50
[ 2868.101132]  rest_init+0xe8/0xf0
[ 2868.101137]  start_kernel+0x7f4/0x800
[ 2868.101143]  __primary_switched+0x88/0x98
[ 2868.101149] handlers:
[ 2868.207750] lan8650 spi0.1: SPI transfer timed out
[ 2868.208070] [<0000000019361c17>] oa_tc6_macphy_isr [lan865x_t1s]
[ 2868.212048] spi_master spi0: failed to transfer one message from queue
[ 2868.215296]  threaded [<00000000a4e6f0fa>] oa_tc6_macphy_threaded_irq 
[lan865x_t1s]
[ 2868.219005] spi_master spi0: noqueue transfer failed

[ 2868.223053] Disabling IRQ #59
[ 2868.260162] lan8650 spi0.1 eth2: SPI data transfer failed: -110
[ 2868.266211] lan8650 spi0.1: Device interrupt disabled to avoid 
interrupt storm

Best regards,
Parthiban V
> 
> But I could see assert in skb_put immediately quickly.
> 
>>
>> Best regards,
>> Parthiban V
>>>
>>>>
>