Revision 9b4fe5fb0bdd8f31f24cbfe77e38ec8155c250c5 authored by Neil Horman on 12 July 2013, 17:35:33 UTC, committed by David S. Miller on 12 July 2013, 23:28:02 UTC
this bug:
https://bugzilla.redhat.com/show_bug.cgi?id=951695

Reported a dma debug backtrace:

WARNING: at lib/dma-debug.c:937 check_unmap+0x47d/0x930()
Hardware name: To Be Filled By O.E.M.
via-rhine 0000:00:12.0: DMA-API: device driver failed to check map error[device
address=0x0000000075a837b2] [size=90 bytes] [mapped as single]
Modules linked in: ip6_tables gspca_spca561 gspca_main videodev media
snd_hda_codec_realtek snd_hda_intel i2c_viapro snd_hda_codec snd_hwdep snd_seq
ppdev mperf via_rhine coretemp snd_pcm mii microcode snd_page_alloc snd_timer
snd_mpu401 snd_mpu401_uart snd_rawmidi snd_seq_device snd soundcore parport_pc
parport shpchp ata_generic pata_acpi radeon i2c_algo_bit drm_kms_helper ttm drm
pata_via sata_via i2c_core uinput
Pid: 295, comm: systemd-journal Not tainted 3.9.0-0.rc6.git2.1.fc20.x86_64 #1
Call Trace:
 <IRQ>  [<ffffffff81068dd0>] warn_slowpath_common+0x70/0xa0
 [<ffffffff81068e4c>] warn_slowpath_fmt+0x4c/0x50
 [<ffffffff8137ec6d>] check_unmap+0x47d/0x930
 [<ffffffff810ace9f>] ? local_clock+0x5f/0x70
 [<ffffffff8137f17f>] debug_dma_unmap_page+0x5f/0x70
 [<ffffffffa0225edc>] ? rhine_ack_events.isra.14+0x3c/0x50 [via_rhine]
 [<ffffffffa02275f8>] rhine_napipoll+0x1d8/0xd80 [via_rhine]
 [<ffffffff815d3d51>] ? net_rx_action+0xa1/0x380
 [<ffffffff815d3e22>] net_rx_action+0x172/0x380
 [<ffffffff8107345f>] __do_softirq+0xff/0x400
 [<ffffffff81073925>] irq_exit+0xb5/0xc0
 [<ffffffff81724cd6>] do_IRQ+0x56/0xc0
 [<ffffffff81719ff2>] common_interrupt+0x72/0x72
 <EOI>  [<ffffffff8170ff57>] ? __slab_alloc+0x4c2/0x526
 [<ffffffff811992e0>] ? mmap_region+0x2b0/0x5a0
 [<ffffffff810d5807>] ? __lock_is_held+0x57/0x80
 [<ffffffff811992e0>] ? mmap_region+0x2b0/0x5a0
 [<ffffffff811bf1bf>] kmem_cache_alloc+0x2df/0x360
 [<ffffffff811992e0>] mmap_region+0x2b0/0x5a0
 [<ffffffff811998e6>] do_mmap_pgoff+0x316/0x3d0
 [<ffffffff81183ca0>] vm_mmap_pgoff+0x90/0xc0
 [<ffffffff81197d6c>] sys_mmap_pgoff+0x4c/0x190
 [<ffffffff81367d7e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
 [<ffffffff8101eb42>] sys_mmap+0x22/0x30
 [<ffffffff81722fd9>] system_call_fastpath+0x16/0x1b

Usual problem with the usual fix, add the appropriate calls to dma_mapping_error
where appropriate

Untested, as I don't have hardware, but its pretty straightforward

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: David S. Miller <davem@davemloft.net>
CC: Roger Luethi <rl@hellgate.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 352900b
Raw File
bt8xxgpio.txt
===============================================================
==  BT8XXGPIO driver                                         ==
==                                                           ==
==  A driver for a selfmade cheap BT8xx based PCI GPIO-card  ==
==                                                           ==
==  For advanced documentation, see                          ==
==  http://www.bu3sch.de/btgpio.php                          ==
===============================================================


A generic digital 24-port PCI GPIO card can be built out of an ordinary
Brooktree bt848, bt849, bt878 or bt879 based analog TV tuner card. The
Brooktree chip is used in old analog Hauppauge WinTV PCI cards. You can easily
find them used for low prices on the net.

The bt8xx chip does have 24 digital GPIO ports.
These ports are accessible via 24 pins on the SMD chip package.


==============================================
==  How to physically access the GPIO pins  ==
==============================================

The are several ways to access these pins. One might unsolder the whole chip
and put it on a custom PCI board, or one might only unsolder each individual
GPIO pin and solder that to some tiny wire. As the chip package really is tiny
there are some advanced soldering skills needed in any case.

The physical pinouts are drawn in the following ASCII art.
The GPIO pins are marked with G00-G23

                                           G G G G G G G G G G G G     G G G G G G
                                           0 0 0 0 0 0 0 0 0 0 1 1     1 1 1 1 1 1
                                           0 1 2 3 4 5 6 7 8 9 0 1     2 3 4 5 6 7
           | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
           ---------------------------------------------------------------------------
         --|                               ^                                     ^   |--
         --|                               pin 86                           pin 67   |--
         --|                                                                         |--
         --|                                                               pin 61 >  |-- G18
         --|                                                                         |-- G19
         --|                                                                         |-- G20
         --|                                                                         |-- G21
         --|                                                                         |-- G22
         --|                                                               pin 56 >  |-- G23
         --|                                                                         |--
         --|                           Brooktree 878/879                             |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|                                                                         |--
         --|   O                                                                     |--
         --|                                                                         |--
           ---------------------------------------------------------------------------
           | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
           ^
           This is pin 1

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