Hi, I'm hitting this warning on boot with a syntek usb video grabber, it's not clear to me if it's a driver issue of the stk1160 or a generic ehci issue. This is with a 3.15-mergewindow kernel (pull of Linus his tree of today). -- Sander [ 5.587759] ------------[ cut here ]------------ [ 5.591210] WARNING: CPU: 0 PID: 1376 at lib/dma-debug.c:1153 check_for_stack+0xa0/0x100() [ 5.596612] ehci-pci 0000:00:0a.0: DMA-API: device driver maps memory fromstack [addr=ffff88003d0b56bf] [ 5.602548] Modules linked in: [ 5.605380] CPU: 0 PID: 1376 Comm: khubd Not tainted 3.14.0-security-20140413-v4lall+ #1 [ 5.611042] Hardware name: Xen HVM domU, BIOS 4.5-unstable 04/10/2014 [ 5.615314] 0000000000000009 ffff88003d0b5348 ffffffff81c516fe ffff88003d0b5390 [ 5.622147] ffff88003d0b5380 ffffffff810e4aa3 ffff88003ceae898 ffff88003cf14070 [ 5.628926] ffff88003d0b56bf ffff88003ceae898 ffffffff8241ab40 ffff88003d0b53e0 [ 5.635536] Call Trace: [ 5.638001] [<ffffffff81c516fe>] dump_stack+0x45/0x56 [ 5.641633] [<ffffffff810e4aa3>] warn_slowpath_common+0x73/0x90 [ 5.645688] [<ffffffff810e4b07>] warn_slowpath_fmt+0x47/0x50 [ 5.649843] [<ffffffff81468820>] check_for_stack+0xa0/0x100 [ 5.652420] systemd-udevd[2143]: starting version 204 [ 5.657709] [<ffffffff814699fc>] debug_dma_map_page+0xfc/0x150 [ 5.661836] [<ffffffff8172109c>] usb_hcd_map_urb_for_dma+0x5fc/0x710 [ 5.666132] [<ffffffff817214c5>] usb_hcd_submit_urb+0x315/0xa30 [ 5.670247] [<ffffffff810ef85a>] ? del_timer_sync+0x4a/0x60 [ 5.674072] [<ffffffff81c6291d>] ? schedule_timeout+0x14d/0x1f0 [ 5.678083] [<ffffffff810ef2a0>] ? migrate_timer_list+0x60/0x60 [ 5.682167] [<ffffffff81722fac>] usb_submit_urb+0x30c/0x580 [ 5.685989] [<ffffffff81c63f4b>] ? wait_for_common+0x16b/0x240 [ 5.689919] [<ffffffff817236fa>] usb_start_wait_urb+0x5a/0xe0 [ 5.693830] [<ffffffff811b0000>] ? mpol_rebind_policy+0x30/0xa0 [ 5.697638] [<ffffffff81723838>] usb_control_msg+0xb8/0x100 [ 5.701468] [<ffffffff81984ab2>] stk1160_read_reg+0x52/0x80 [ 5.705358] [<ffffffff8198690c>] stk1160_i2c_busy_wait+0x6c/0x90 [ 5.709656] [<ffffffff81986afb>] stk1160_i2c_xfer+0x1cb/0x440 [ 5.713647] [<ffffffff81126052>] ? irq_to_desc+0x12/0x20 [ 5.717515] [<ffffffff81129329>] ? irq_get_irq_data+0x9/0x10 [ 5.721432] [<ffffffff8178a1ac>] __i2c_transfer+0x5c/0x80 [ 5.725783] [<ffffffff8178b48b>] i2c_transfer+0x5b/0x90 [ 5.730187] [<ffffffff8178b676>] i2c_smbus_xfer_emulated+0x116/0x570 [ 5.735194] [<ffffffff8110f8ce>] ? wake_up_process+0x1e/0x40 [ 5.739631] [<ffffffff81c63f4b>] ? wait_for_common+0x16b/0x240 [ 5.744338] [<ffffffff8111da6f>] ? __wake_up+0x3f/0x50 [ 5.748997] [<ffffffff8178bbc2>] i2c_smbus_xfer+0xf2/0x140 [ 5.753538] [<ffffffff8178bcd3>] i2c_default_probe+0xc3/0x100 [ 5.758173] [<ffffffff8178a586>] ? i2c_check_addr_busy+0x36/0x60 [ 5.763227] [<ffffffff8178a892>] i2c_new_probed_device+0x92/0xe0 [ 5.768736] [<ffffffff8178bc10>] ? i2c_smbus_xfer+0x140/0x140 [ 5.774035] [<ffffffff81844bdf>] v4l2_i2c_new_subdev_board+0x4f/0x100 [ 5.779495] [<ffffffff81844ce8>] v4l2_i2c_new_subdev+0x58/0x70 [ 5.784638] [<ffffffff81984fdf>] stk1160_probe+0x3df/0x4e0 [ 5.789553] [<ffffffff81726dda>] usb_probe_interface+0xca/0x1d0 [ 5.794659] [<ffffffff816408d6>] really_probe+0x56/0x1e0 [ 5.799231] [<ffffffff81640a60>] ? really_probe+0x1e0/0x1e0 [ 5.804225] [<ffffffff81640aa8>] __device_attach+0x48/0x50 [ 5.809514] [<ffffffff8163ecf3>] bus_for_each_drv+0x53/0x90 [ 5.814602] [<ffffffff81640868>] device_attach+0x88/0xa0 [ 5.819487] [<ffffffff8163fe08>] bus_probe_device+0x98/0xc0 [ 5.824337] [<ffffffff8163dfbc>] device_add+0x4bc/0x5c0 [ 5.829267] [<ffffffff81725a15>] usb_set_configuration+0x495/0x7a0 [ 5.834590] [<ffffffff8172eff9>] generic_probe+0x29/0xa0 [ 5.839419] [<ffffffff81725db5>] usb_probe_device+0x15/0x20 [ 5.844594] [<ffffffff816408d6>] really_probe+0x56/0x1e0 [ 5.849538] [<ffffffff81640a60>] ? really_probe+0x1e0/0x1e0 [ 5.854444] [<ffffffff81640aa8>] __device_attach+0x48/0x50 [ 5.859393] [<ffffffff8163ecf3>] bus_for_each_drv+0x53/0x90 [ 5.864390] [<ffffffff81640868>] device_attach+0x88/0xa0 [ 5.869408] [<ffffffff8163fe08>] bus_probe_device+0x98/0xc0 [ 5.874652] [<ffffffff8163dfbc>] device_add+0x4bc/0x5c0 [ 5.879185] [<ffffffff8171aec8>] usb_new_device+0x228/0x390 [ 5.884283] [<ffffffff8171da60>] hub_thread+0xdb0/0x14e0 [ 5.888638] [<ffffffff8110f6f0>] ? try_to_wake_up+0x100/0x2c0 [ 5.892802] [<ffffffff8111dec0>] ? abort_exclusive_wait+0xa0/0xa0 [ 5.896554] [<ffffffff8171ccb0>] ? usb_reset_device+0x180/0x180 [ 5.900309] [<ffffffff81103e3d>] kthread+0xcd/0xf0 [ 5.903619] [<ffffffff81103d70>] ? kthread_create_on_node+0x170/0x170 [ 5.908064] [<ffffffff81c6754c>] ret_from_fork+0x7c/0xb0 [ 5.912017] [<ffffffff81103d70>] ? kthread_create_on_node+0x170/0x170 [ 5.916654] ---[ end trace 18f58175dc2f3152 ]--- -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html