Hello, I found a bug in echoaudio.c. When the driver fails at the function snd_echo_create(), it should release resources requested before, otherwise we will get the following warning: [ 3.262866] remove_proc_entry: removing non-empty directory 'irq/21', leaking at least 'snd_indigodj' [ 3.263577] WARNING: CPU: 3 PID: 261 at fs/proc/generic.c:717 remove_proc_entry+0x389/0x3f0 [ 3.267098] RIP: 0010:remove_proc_entry+0x389/0x3f0 [ 3.269976] Call Trace: [ 3.269979] <TASK> [ 3.269988] unregister_irq_proc+0x14c/0x170 [ 3.269997] irq_free_descs+0x94/0xe0 [ 3.270004] mp_unmap_irq+0xb6/0x100 [ 3.270011] acpi_unregister_gsi_ioapic+0x27/0x40 [ 3.270017] acpi_pci_irq_disable+0x1d3/0x320 [ 3.270025] pci_disable_device+0x1ad/0x380 [ 3.270034] pcim_release+0x566/0x6d0 [ 3.270046] devres_release_all+0x1f1/0x2c0 [ 3.270057] really_probe+0xe0/0x920 Regards, Zheyu Ma