(bugtrack #2932). The interface is two USB devices in the same physical
box. Note that this is the USB ScratchAmp v1 and not the later v2
(firewire) model.
Signed-off-by: Mark Hills <mark@pogo.org.uk>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Following the suggestion in this thread:
https://bugs.launchpad.net/ubuntu/+source/alsa-lib/+bug/26683
the correct upper bound on desc[0] is 5 + num_ins not 6 + num_ins,
because the index used later is 5+i, not 6+i.
This change makes my Vosky Chatterbox speakerphone work.
Apparently it also helps with the Minivox MV100.
Signed-off-by: Russ Cox <rsc@swtch.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
input_free_device()'s comment says:
input_free_device() should only be used if input_register_device() was
not called yet or if it failed. Once device was registered
use input_unregister_device() and memory will be freed once last
refrence to the device is dropped.
Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Clean up codes using the new common snd_ctl_boolean_*_info() callbacks.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Fixed AC3 interface in device_setup=0x00 mode thanks to Hakan
Lennestal and updated documentation
Signed-off-by: Thibault Le Meur <Thibault.LeMeur@supelec.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Audiophile-usb fix (corrects little-endianness in 16bit
modes, resets interfaces at device initialization, and updates the
documentation).
Signed-off-by: Thibault Le Meur <Thibault.LeMeur@supelec.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
This patch adds Logitech QuickCam USB ID for Dell's
XPS M1210 notebooks.
Signed-off-by: Ritesh Raj Sarraf <rrs@researchut.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
From: George Shapovalov <george@gentoo.org>
Another case of ALSA ticket #3040: we need an explicit USB ID match for
another Logitech camera/microphone device.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Added a quirk for Roland EXR series. Reported by Andre Coetzee.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Added a quirk for Roland Juno-G. It's simply a copy of Fantom-X with the
IDs changed.
From: Claudio Matsuoka <cmatsuoka@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Add quirks to detect the Roland SH-201.
Signed-off-by: Carlo Beccaria <carlo@beccaria.org>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
if (!x) kfree(x); is not needed since kfree(NULL) is valid.
Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
This patch adds the ID for another quickcam microphone, reported by freqmod
on ALSA ticket #0003040
I'm going to submit a USB patch separately to provide a macro to simplify these
entries, as suggested by Alan Stern. We could switch to using that in future.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
This patch makes sure that short USB replies are treated as an
error when requesting the value of a certain mixer control.
Signed-off-by: Thomas Reitmayr <thomas@devbase.at>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
This patch adds the ID for another quickcam microphone, reported by freqmod
on ALSA ticket #0003040
I'm going to submit a USB patch separately to provide a macro to simplify these
entries, as suggested by Alan Stern. We could switch to using that in future.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Add a workaround for the ESI M4U that claims to support 32-byte packets
but ignores the remaining bytes of packets bigger than four bytes.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
The firmware of the M-Audio USB Uno MIDI Interface has, at least in
hardware revision 1.25, a bug that garbles its USB output. When it
receives a Note On MIDI message that uses running status, the resulting
USB MIDI packet has a wrong CIN (4 instead of 9) and a wrong length
(2 bytes, the status byte is still missing).
This patch adds a workaround to track the CINs and the MIDI messages of
received USB MIDI packets to detect whether a packet with CIN 4 is a
correct SysEx packet or a buggy running status packet.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
The last patch didn't really work (false report).
Although the hardware supports 125us minimum period, the current
usb-audio driver code assumes the 1ms period in many places.
Rollback the change.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
The minimal period size is 125us for high-speed mode while
1ms for full-speed mode.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Add support for the PCM interfaces of the Edirol PCR-A.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Recent changes in usbcore removed the bandwidth field from struct urb.
Remove the occurence in usbaudio.c
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Added support for the Edirol UA-101 (only in high-speed mode) by taking
the quirks for the UA-1000 and change them accordingly. Changes were
made in 'usbaudio.c', 'usbaudio.h', and 'usbquirks.h'
MIDI and recording seem to work perfectly (with JACK), but playback
gives some few glitches. I think that's the mentioned
synchronizing-problem in the UA-1000 quirk ('FIXME: playback must be
synchronized to capture'), so I didn't change that.
ToDo: Adding Mixer-Support for the built-in
control-panel/patch-bay/router.
Signed-off-by: Bjoern Fay <mail@bfay.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
The patch fixes the memory corruption by the support of unconventional
sample rates. Also, it avoids the too restrictive constraints if
any of usb descriptions contain continuous rates.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
This is a patch for ALSA Bug #2724. Some webcams provide bogus
settings with no valid rates. With this patch those are skipped.
Signed-off-by: Gregor Jasny <gjasny@web.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Went rummaging through usbaudio.c and found some castings that
aren't needed as far as I can see. Part of the KernelJanitors
TODO list.
Signed-off-by: John Daiker <daikerjohn@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Add pause capabilities for both USB playback and capture streams.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
The hardware information structures for playback and capture streams,
respectively, are the same, so we can use just one structure for both
streams.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
The previous patch 'Repair snd-usb-usx2y for usb 2.6.18' assumed
urb->start_frame roll over beyond MAX_INT for both UHCI & OHCI.
This isn't true until now (kernel 2.6.20).
Fix this by only looking at the common between OHCI & UHCI Frame number
range.
This is for mainline and stable kernels >= 2.6.18.
Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Fixed the error from kobject_add() at reconnection the usb audio device.
This happens when an app keeps opening a device while the device is
replugged, due to the confliction of the internal bookkept index and
the really empty slot.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Without the patch below namelist[0] will not be freed in case
of kmalloc error.
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
The C-Media CM6501 chip's descriptors say that altsetting 5 supports
48 kHz, but it actually plays at 96 kHz.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Handle the return value of usb_register() in the module_init function.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Some drivers are returning OOM when it is not in response to a memory
shortage.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix hang-up at disconnection of usb-audio devices while accessing PCM.
Don't handle PCM operations any more after shutdown flag is set.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
urb->start_frame rolls over beyond MAX_INT now.
This is for stable kernel and stable alsa.
Signed-off-by: Karsten Wiese <annabellesgarden@yahoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Fix bug in snd-usb-usx2y's usX2Y_pcms_lock_check()
substream can be NULL......
in mainline, bug was introduced by:
2006-06-22 [ALSA] Add O_APPEND flag support to PCM
Signed-off-by: Karsten Wiese <annabellesgarden@yahoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
The purpose of this patch is to split off the case when a device does
not reply on the lower level (which is reported by HC hardware), and
a case when the device accepted the request, but does not reply at
upper level. This redefinition allows to diagnose issues easier,
without asking the user if the -110 happened "immediately".
The usbmon splits such cases already thanks to its timestamp, but
it's not always available.
I adjusted all drivers which I found affected (by searching for "urb").
Out of tree drivers may suffer a little bit, but I do not expect much
breakage. At worst they may print a few messages.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add a mixer name map for the TerraTec Aureon 5.1 MkII USB.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
To decrease the USB interrupts rate, increase both the default and the
maximum number of packets per URB.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
There's at least one USB audio chipset out there which supports only one
non-standard rate (ID 0e6a:0310 supports 46875Hz). There's a few other
patches for this card which are unsatisfactory because they attempt to
map this rate to 44.1k leading to sound distortion.
The patch below uses SNDRV_PCM_RATE_KNOT to properly support the
non-standard rates where they are available.
Signed-off-by: Luke Ross <luke@lukeross.name>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Fixed a typo of CONFIG_PROC_FS in usbaudio.c.
The stream proc file appears again.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Add some quirks for some unknown Yamaha USB MIDI devices.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Added TLV-read support to snd-usb-audio driver for passing
the volume dB scale information to user-space.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Orignally proposed by Sam Revitch <sam.revitch@gmail.com>.
Unregister device files at disconnection to avoid the futher accesses.
Also, the dev_unregister callback is removed and replaced with the
combination of disconnect + free.
A new function snd_card_free_when_closed() is introduced, which is
used in USB disconnect callback.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
From: Sam Revitch <sam.revitch@gmail.com>Recently a Turtle Beach Audio Advantage Roadie device ended up in my
possession. It seems to work with the snd-usb-audio driver, but only
using the headphone jack in 2-channel mode. The device has a DIN
connector carrying six more channels that are otherwise silent.
C-Media has freely available documentation for the CM106 chip around
which this device is based, and enabling 8-channel output, or
6-channel output with the headphone jack following the front pair is a
matter of setting one of its registers.
Attached is a patch to try to enable 5.1 output mode at probe time.
It seems to work correctly with my device. There is quite list of
other configurables for this device that might deserve controls.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Removed the CS_AUDIO_* #defines, which were duplicates of the
class-specific USB_DT_CS_* #defines in <linux/usb_ch9.h>.
Signed-off-by: Ben Williamson <ben.williamson@greyinnovation.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Some devices don't have the required class-specific endpoint descriptors.
Instead of making this case an error, this patch makes the driver guess the
endpoint attributes.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
This patch rewrites the remote control code to use a table for
the peculiarities of the various SB models, and adds support
for a third model.
Signed-off-by: Raimonds Cicans <ray@vardes.lv>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Add a get_port_info callback to the snd_rawmidi_global_ops structure to
allow the USB MIDI driver to supply information flags for the sequencer
ports created by seq_midi.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Added O_APPEND flag support to PCM to enable shared substreams
among multiple processes. This mechanism is used by dmix and
dsnoop plugins.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Test the volume of usb audio whether actually it works and adjusts
the resolution value according to it.
Some USB audio devices report a lower resolution than it reacts.
The only possible check is to write and read a volume value.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Fix a lot of typos. Eyeballed by jmc@ in OpenBSD.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Modules: USB generic driver
We may leak 'namelist' in sound/usb/usbmixer.c::parse_audio_selector_unit()
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Modules: Documentation,USB generic driver
The patch adds the 'device_setup' module parameter and a specific
quirk to correctly initialize the audiophile usb device: this fixes
the distorted sound bug on the Analog capture port. Backward
compatibility is achieved by simply omitting the new parameter.
Signed-off-by: Thibault LE MEUR <Thibault.LeMeur@supelec.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Modules: USB generic driver
Add an error message for -ENOSYS for situations when split iso support
is needed but not enabled.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
Use a generic name for USB device 0x07cf:0x6802 because this ID is used
by several devices without a product ID.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
When usb_submit_urb() fails, show an error description instead of just
the error code.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
snd_ctl_add() kfree's the kcontrol already if we fail there,
so this driver is currently doing a double kfree.
Coverity bug #959
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Modules: USB generic driver
Reduce the code size of the snd_usbmidi_count_bits() function by using
simpler operations.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: Digigram VX core,USB generic driver
There's no need to check pointers passed to vfree() for NULL.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Modules: USB generic driver
Rename QUIRK_MIDI_MIDITECH to QUIRK_MIDI_CME because Miditech keyboards
are built by CME and use the same protocol, and don't force a Miditech
product name for the USB ID used by both Miditech and CME UF-x
keyboards.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: PCM Midlevel,USB generic driver
Because snd_pcm_format_name() function is used only for informational
purposes, it is no longer exported from the PCM midlevel to reduce
space and dependency. usbaudio module shows only numeric value for format.
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Modules: ALSA Core,PCM Midlevel,ALSA<-OSS emulation,USB generic driver
1) The verbose procfs code for the PCM midlevel and usb audio
can be removed now (more patches will follow).
CONFIG_SND_VERBOSE_PROCFS
2) The PCM OSS plugin system can be also compiled optionaly.
CONFIG_SND_PCM_OSS_PLUGINS
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Modules: USB generic driver
Move the common packet size calculation code from
prepare_startup_playback_urb() and prepare_playback_urb() to a new
function.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
This is my naive attempt at adding ALSA device support. The attached
patch provides support for the EDIROL UM-3ex. This is a 3-port USB midi
interface with a built-in USB hub and the ability to chain 2 other
UM-3x's in a master-slave configuration. I only have one, so I do not
know how this works in practice.
Though this is a 3-port device, I had to throw in that 4th 'Control' interface
to the definition in order to make the 3rd port work. If I set in/out_cables
to 0x000b, a 3rd interface appears on the driver, but it does nothing.
Changing it to 0x000f allows the 3rd interface to work, but of course
interface 4 does not work because it does not exist.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Modules: USB generic driver
On the Audigy 2 ZS, disable all sample rate that are not a multiple of
48 kHz because the others work only with the digital output which is
not yet supported.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
Some widespread USB interface chips with adaptive iso endpoints hang
after receiving a series of empty packets when they expect data (ALSA
bug#1585). To avoid this, we have to send packets containing silence
(zero samples) instead.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
Somebody at Edirol fucked up and released a new revision of the UA-20
without class-specific descriptors, so now we have to hard-code the
sample format.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Something noticed when studying use of VM_RESERVED in different drivers:
snd_usX2Y_hwdep_pcm_vm_nopage omitted to get_page: fixed.
And how did this work before? Aargh! That nopage is returning a page from
within a buffer allocated by snd_malloc_pages, which allocates a high-order
page, then does SetPageReserved on each 0-order page within.
That would have worked in 2.6.14, because when the area was unmapped,
PageReserved inhibited put_page. 2.6.15-rc1 removed that inhibition (while
leaving ineffective PageReserveds around for now), but it hasn't caused
trouble because.. we've not been freeing from VM_RESERVED at all.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
