Dear IIO Maintainers,
I'm starting studying IIO framework in order to migrate our acquisition
systems, based on fast ADC, to this framework.
So far we are using our framework named ZIO which was developed more
than 10 years ago, when IIO was not mature enough to handle high speed
constraints, large DMA transfer(>256MB) and zero copy.
Out of curiosity https://ohwr.org/project/zio
The idea is to get rid of our local framework and move to IIO to benefit
from the large Users community.
For now, most of our drivers are running on x86_64 architecture, even if
future applications will run on SoC (Zynq UltraScale+).
I made a first prototype, widely inspired from your "ad_adc.c" driver
found on your git repo, with a 4.18 kernel. I am facing some issues
including kernel Oops while unloading the module.
Could you please let me know which minimal kernel version is required to
use the "IIO DMA engine buffer" features. In addition, I would really
appreciate if you could point me to some reference IIO ADC driver
implementation that handles similar DMA transfer size with good
performances.
Thanks in advance for your answer.
Best regards,
Michel Arruat.
Oops:
[ 1110.718286] Oops: 0000 [#1] SMP PTI
[ 1110.759964] CPU: 5 PID: 155923 Comm: rmmod Kdump: loaded Tainted: P
W OE --------- - - 4.18.0-193.28.1.el8_2.x86_64 #1
[ 1110.900606] Hardware name: National Instruments NI PXIe-8861/NI
PXIe-8861, BIOS 1.2.4f2 01/09/2020
[ 1111.007906] RIP: 0010:kernfs_find_ns+0x17/0xc0
[ 1111.061042] Code: c0 79 04 31 ff eb f4 89 c2 eb e3 0f 1f 84 00 00 00
00 00 0f 1f 44 00 00 41 55 48 85 d2 49 89 f5 41 54 0f 95 c1 55 48 89 d5
53 <0f> b7 47 70 66 83 e0 20 0f 95 c2 38 d1 75 52 48 8b 5f 48 48 89 ee
[ 1111.286038] RSP: 0018:ffffa5b406e67d08 EFLAGS: 00010246
[ 1111.348548] RAX: 0000000000000000 RBX: 0000000000000000 RCX:
0000000000000000
[ 1111.433971] RDX: 0000000000000000 RSI: ffffffffb5ab1588 RDI:
0000000000000000
[ 1111.519394] RBP: 0000000000000000 R08: ffffa5b406e67e18 R09:
0000000000000004
[ 1111.604828] R10: 0000000000000000 R11: 0000000000000001 R12:
0000000000000000
[ 1111.690250] R13: ffffffffb5ab1588 R14: ffff99f3c8c82ae0 R15:
ffff99f435506390
[ 1111.775673] FS: 00007f5690560740(0000) GS:ffff99f435b40000(0000)
knlGS:0000000000000000
[ 1111.872553] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1111.941310] CR2: 0000000000000070 CR3: 0000000248d1a002 CR4:
00000000003606e0
[ 1112.026732] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 1112.112156] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 1112.197596] Call Trace:
[ 1112.226778] kernfs_find_and_get_ns+0x2c/0x50
[ 1112.278872] sysfs_unmerge_group+0x18/0x60
[ 1112.327843] dpm_sysfs_remove+0x27/0x60
[ 1112.373688] device_del+0x85/0x380
[ 1112.414323] cdev_device_del+0x15/0x30
[ 1112.459143] iio_device_unregister+0x29/0x70 [industrialio]
[ 1112.525821] release_nodes+0x21d/0x270
[ 1112.570626] device_release_driver_internal+0xf4/0x1d0
[ 1112.632094] driver_detach+0x54/0x88
[ 1112.674814] bus_remove_driver+0x77/0xc9
[ 1112.721704] pci_unregister_driver+0x2d/0xb0
[ 1112.772758] __x64_sys_delete_module+0x139/0x280
[ 1112.827977] do_syscall_64+0x5b/0x1a0
