Hi
Am 18.06.25 um 18:03 schrieb Zenghui Yu:
Hi all,
Running the dmabuf-heap test [*] on mainline kernel triggers the
following splat:
------------[ cut here ]------------
DMA-API: platform vgem: mapping sg segment longer than device claims to
support [len=1048576] [max=65536]
Thanks for the bug report. We have a possible fix in the latest
drm-misc-next tree. Does it work if use replace DRM_GEM_SHMEM_DRIVER_OPS
with DRM_GEM_SHMEM_DRIVER_OPS_NO_MAP_SGT at [1]?
[1]
https://elixir.bootlin.com/linux/v6.16-rc2/source/drivers/gpu/drm/vgem/vgem_drv.c#L118
Best regards
Thomas
WARNING: CPU: 7 PID: 1126 at kernel/dma/debug.c:1174
debug_dma_map_sg+0x348/0x3e4
Modules linked in: vgem drm_shmem_helper drm_kms_helper rfkill drm fuse
backlight sha3_ce sha512_ce ipv6
CPU: 7 UID: 0 PID: 1126 Comm: dmabuf-heap Kdump: loaded Not tainted
6.16.0-rc2-00024-g9afe652958c3-dirty PREEMPT
Hardware name: QEMU QEMU Virtual Machine, BIOS
edk2-stable202408-prebuilt.qemu.org 08/13/2024
pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : debug_dma_map_sg+0x348/0x3e4
lr : debug_dma_map_sg+0x348/0x3e4
sp : ffff800084313a50
x29: ffff800084313a50 x28: ffff0000c0a62480 x27: 0000000000000001
x26: ffffffffffffffff x25: 0000000000000000 x24: ffff0000c0985f20
x23: ffff8000815ab058 x22: 0000000000000001 x21: 0000000000000001
x20: 0000000000000000 x19: ffff0000c2797010 x18: 0000000000000020
x17: 0000000000000000 x16: 0000000000000000 x15: 00000000ffffffff
x14: ffff8000815c6390 x13: 00000000000005bb x12: 00000000000001e9
x11: fffffffffffe8360 x10: ffff80008161e390 x9 : 00000000fffff000
x8 : ffff8000815c6390 x7 : ffff80008161e390 x6 : 0000000000000000
x5 : ffff0001fee21308 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000c5ea4600
Call trace:
debug_dma_map_sg+0x348/0x3e4 (P)
__dma_map_sg_attrs+0xbc/0x118
dma_map_sgtable+0x28/0x44
system_heap_map_dma_buf+0x2c/0x64
dma_buf_map_attachment+0x60/0x184
dma_buf_map_attachment_unlocked+0x3c/0x7c
drm_gem_prime_import_dev.part.0+0x58/0x130 [drm]
drm_gem_prime_import+0x48/0xc4 [drm]
drm_gem_prime_fd_to_handle+0x180/0x220 [drm]
drm_prime_fd_to_handle_ioctl+0x38/0x44 [drm]
drm_ioctl_kernel+0xb8/0x12c [drm]
drm_ioctl+0x204/0x4ec [drm]
__arm64_sys_ioctl+0xac/0x104
invoke_syscall+0x48/0x110
el0_svc_common.constprop.0+0x40/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x34/0x108
el0t_64_sync_handler+0xc8/0xcc
el0t_64_sync+0x198/0x19c
---[ end trace 0000000000000000 ]---
The kernel is built with arm64's virtconfig and
+CONFIG_DMABUF_HEAPS=y
+CONFIG_DMABUF_HEAPS_SYSTEM=y
+CONFIG_DRM_VGEM=m
+CONFIG_DMA_API_DEBUG=y
[*] linux/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
Thanks,
Zenghui
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
