[mythtv-users] problems with armv5tel and hdpvr

James Maclaren maclaren at tulane.edu
Sat Jul 31 00:48:23 UTC 2010

I am not sure if this is the right list or not, but I have, for fun, 
installed a mythbackend on a Seagte Dockstar runn ing archlinux  When I try to record from my hd-pvr I get this.

kernel BUG at arch/arm/mm/dma-mapping.c:409!
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c0004000
[00000000] *pgd=00000000
Internal error: Oops: 817 [#1] PREEMPT
last sysfs file: 
Modules linked in: pl2303 usbserial hdpvr v4l2_common videodev 
v4l1_compat ipv6 mv_cesa
CPU: 0    Not tainted  ( #1)
PC is at __bug+0x18/0x24
LR is at __bug+0x14/0x24
pc : [<c002e6f4>]    lr : [<c002e6f0>]    psr: 40000013
sp : c60bdee0  ip : c60bde50  fp : c62b7ec0
r10: c6dcbf6c  r9 : c60bdf54  r8 : 00000000
r7 : 000000d0  r6 : 00000002  r5 : 00002000  r4 : ffc0b000
r3 : 00000000  r2 : c60bded4  r1 : c04815fd  r0 : 00000033
Flags: nZcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 0005317f  Table: 06160000  DAC: 00000017
Process hdpvr_buffer (pid: 1379, stack limit = 0xc60bc270)
Stack: (0xc60bdee0 to 0xc60be000)
dee0: ffc0b000 c0030910 c62b5e80 c7ea0c00 ffc0b000 c02b59a0 c608e000 
df00: c05357ac ffffffff c0506000 00000002 c6dcbf00 c6dcbf14 00000000 
df20: 00000000 c60bdf54 c6dcbf6c bf07860c 00000001 c0036cf4 c608e960 
df40: c6dcbf74 c6dcbf7c c6dcbf90 c60bdf60 00000b27 c004fce8 c608e000 
df60: c608e990 c608e960 c608e990 c62b7ea0 c60bc000 c62b7ea8 bf078578 
df80: c6dcbf94 00000000 c6dcbf90 c004fdb4 00000000 00000000 c608e960 
dfa0: c60bdfa0 c60bdfa0 c62b7ea0 c6fefdc0 c60bdfd4 c004fc2c c62b7ea0 
dfc0: 00000000 00000000 00000000 c0053494 00000000 00000000 c60bdfd8 
dfe0: 00000000 00000000 00000000 00000000 00000000 c002c414 00000000 
[<c002e6f4>] (__bug+0x18/0x24) from [<c0030910>] 
[<c0030910>] (___dma_single_cpu_to_dev+0x40/0xa8) from [<c02b59a0>] 
[<c02b59a0>] (usb_hcd_submit_urb+0x6fc/0x884) from [<bf07860c>] 
(hdpvr_transmit_buffers+0x94/0x2c0 [hdpvr])
[<bf07860c>] (hdpvr_transmit_buffers+0x94/0x2c0 [hdpvr]) from 
[<c004fdb4>] (worker_thread+0x188/0x240)
[<c004fdb4>] (worker_thread+0x188/0x240) from [<c0053494>] 
[<c0053494>] (kthread+0x78/0x80) from [<c002c414>] 
Code: e1a01000 e59f000c eb0eadcf e3a03000 (e5833000)
---[ end trace 47eeb8d36d67070f ]---
usb 1-1.2: USB disconnect, address 4

I have downloaded the latest v4l-dvb code and compiled no problem. I 
have tried compiling a kernel.  Has anyone used a hd-pvr on an arm 
processor.  I don't have much memory left once the backend and mysql are 
running but they seem to work fine.  I can record and playback on a 
remote frontend shows recorded on the hdhomerun.
line 409 in that file is
BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1));

Not even sure how to debug this one.  Any pointers/help would be 


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