[alsa-devel] Atmel_usba_udc: Kernel panic in usba_ep_enable

[Angelo Compagnucci]

Hello List,

I'm having troubles with usb audio on an SAMA5D3 on 3.19.8 with a
strange kernel panic.

The function f_audio_set_alt (f_uac1.c) is passing a NULL out_ep and
so the usba_ep_enable crashes with a null pointer dereference as you
can see from the debugging output:

[   24.210000] ep1: ep_enable: desc=  (null)

Unfortunately, there is nothing strange with my configuration, I'm
trying to use the soundcard (which plays files flawlessly) as a usb
soundcard, so the only thing I did was to compile g_audio as a module,
enable UAC1 and did a modprode.

Can you share any advice?

Following kernel panic output:

[   23.500000] g_audio gadget: adding config #1 'Linux USB Audio
Gadget'/bf0232c8
[   23.510000] g_audio gadget: adding 'g_audio'/cf9c6400 to config
'Linux USB Audio Gadget'/bf0232c8
[   23.600000] g_audio gadget: Hardware params: access 3, format 2,
channels 2, rate 48000
[   23.630000] g_audio gadget: cfg 1/bf0232c8 speeds: high full
[   23.630000] g_audio gadget:   interface 0 = g_audio/cf9c6400
[   23.640000] g_audio gadget:   interface 1 = g_audio/cf9c6400
[   23.640000] g_audio gadget: Linux USB Audio Gadget, version: Feb 2, 2012
[   23.650000] g_audio gadget: g_audio ready
[   24.200000] g_audio gadget: high-speed config #1: Linux USB Audio Gadget
[   24.200000] g_audio gadget: intf 0, alt 0
[   24.200000] g_audio gadget: intf 1, alt 0
[   24.210000] g_audio gadget: intf 1, alt 1
[   24.210000] ep1: ep_enable: desc=  (null)
[   24.210000] Unable to handle kernel NULL pointer dereference at
virtual address 00000002
[   24.210000] pgd = c0004000
[   24.210000] [00000002] *pgd=00000000
[   24.210000] Internal error: Oops: 17 [#1] ARM
[   24.210000] Modules linked in: usb_f_uac1 g_audio libcomposite
[   24.210000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.19.8+ #69
[   24.210000] Hardware name: Atmel SAMA5 (Device Tree)
[   24.210000] task: c052c7b8 ti: c0522000 task.ti: c0522000
[   24.210000] PC is at usba_ep_enable+0x28/0x200
[   24.210000] LR is at usba_ep_enable+0x24/0x200
[   24.210000] pc : [<c02815bc>]    lr : [<c02815b8>]    psr: 200f0193
[   24.210000] sp : c0523e18  ip : 00000007  fp : 0000bb80
[   24.210000] r10: 00000100  r9 : cfb17c00  r8 : 00000001
[   24.210000] r7 : 000000c8  r6 : cf99aa10  r5 : 00000000  r4 : cf99d868
[   24.210000] r3 : 00000006  r2 : 00000007  r1 : 00000000  r0 : 00000001
[   24.210000] Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM
Segment kernel
[   24.210000] Control: 10c53c7d  Table: 2fb28059  DAC: 00000015
[   24.210000] Process swapper (pid: 0, stack limit = 0xc0522230)
[   24.210000] Stack: (0xc0523e18 to 0xc0524000)
[   24.210000] 3e00:
    00000001 cf99d868
[   24.210000] 3e20: cf9c6400 bf028694 00000001 c0530008 cfa13ac0
cfb17c00 cfb17a00 00000001
[   24.210000] 3e40: cf9c6400 00000001 00000001 cf99aa18 00000000
bf015104 c0523e74 c0034d9c
[   24.210000] 3e60: cf9471c0 600f0193 cfb05f6c c0530704 c00398b8
c00398c4 c05306f8 c0039400
[   24.210000] 3e80: 00000000 200f0193 00000007 00000006 00000000
cf99d810 0000000b cf99d848
[   24.210000] 3ea0: cf99aa10 00000000 00000000 00000000 00000800
c0282f0c 0000001c ffffffff
[   24.210000] 3ec0: 7fffffff c0547d80 00000000 00000125 00000001
c054e23e 00010b01 00000001
[   24.210000] 3ee0: 00000000 cf998240 cf802540 00000000 00000000
0000002d cf901dc0 c054e23e
[   24.210000] 3f00: 00000000 c0040af0 cf802200 c054eb00 cf901dc0
cf802540 00000000 00000000
[   24.210000] 3f20: cf802200 c051ac50 cfffc480 c0040be0 cf901dc0
c0042e00 0000002d 0000002d
[   24.210000] 3f40: 00000000 c0040314 c0534ca0 c0040538 c000eec4
600f0013 ffffffff c0523f9c
[   24.210000] 3f60: c054e340 c0011b00 00000000 c0530918 00000000
c0017880 c0522000 c052a0c4
[   24.210000] 3f80: c054e23c c054e23c c054e340 c051ac50 cfffc480
00000000 01000000 c0523fb0
[   24.210000] 3fa0: c000eec0 c000eec4 600f0013 ffffffff c0522000
c0039b58 ffffffff c04f5c30
[   24.210000] 3fc0: ffffffff ffffffff c04f5678 00000000 00000000
c051ac50 c054e514 c052a070
[   24.210000] 3fe0: c051ac4c c052d860 20004059 410fc051 00000000
20008070 00000000 00000000
[   24.210000] [<c02815bc>] (usba_ep_enable) from [<bf028694>]
(f_audio_set_alt+0xc4/0x19c [usb_f_uac1])
[   24.210000] [<bf028694>] (f_audio_set_alt [usb_f_uac1]) from
[<bf015104>] (composite_setup+0x4e0/0x1640 [libcomposite])
[   24.210000] [<bf015104>] (composite_setup [libcomposite]) from
[<c0282f0c>] (usba_udc_irq+0x75c/0xc74)
[   24.210000] [<c0282f0c>] (usba_udc_irq) from [<c0040af0>]
(handle_irq_event_percpu+0x78/0x140)
[   24.210000] [<c0040af0>] (handle_irq_event_percpu) from
[<c0040be0>] (handle_irq_event+0x28/0x38)
[   24.210000] [<c0040be0>] (handle_irq_event) from [<c0042e00>]
(handle_fasteoi_irq+0x9c/0x164)
[   24.210000] [<c0042e00>] (handle_fasteoi_irq) from [<c0040314>]
(generic_handle_irq+0x2c/0x3c)
[   24.210000] [<c0040314>] (generic_handle_irq) from [<c0040538>]
(__handle_domain_irq+0x54/0xa8)
[   24.210000] [<c0040538>] (__handle_domain_irq) from [<c0011b00>]
(__irq_svc+0x40/0x54)
[   24.210000] [<c0011b00>] (__irq_svc) from [<c000eec4>]
(arch_cpu_idle+0x38/0x3c)
[   24.210000] [<c000eec4>] (arch_cpu_idle) from [<c0039b58>]
(cpu_startup_entry+0xa8/0xf4)
[   24.210000] [<c0039b58>] (cpu_startup_entry) from [<c04f5c30>]
(start_kernel+0x374/0x380)
[   24.210000] Code: e5941004 e5946024 eb04d705 e5d40033 (e5d51002)
[   24.210000] ---[ end trace d5ac053970e7d2d1 ]---
[   24.210000] Kernel panic - not syncing: Fatal exception in interrupt
[   24.210000] ---[ end Kernel panic - not syncing: Fatal exception in interrupt


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