Modules: USB generic driver
If we submit all our URBs when a playback stream is started, the first
hwptr_done update for each URB happens at the same time. This results
in an underrun when there isn't enough PCM data available at this
point for all URBs.
To avoid this, we begin submitting our URBs earlier (when the stream
is prepared), with empy packets. When the stream is started, the
prepare_playback_urb() call for each URB will be run only when the
respective URB has completed previously, so the first hwptr_done
updates will be done nicely staggered.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use schedule_timeout_{,un}interruptible() instead of
set_current_state()/schedule_timeout() to reduce kernel size. Also use
human-time conversion functions instead of hard-coded division to avoid
rounding issues.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Modules: USB generic driver
Remove the usb_reset_configuration() call from the probe callback
because it isn't needed and it may interfere with other drivers
already loaded for the device.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
- Remove vmalloc wrapper
- Add release_and_free_resource() to remove kfree_nocheck() from each driver
and simplify the code
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Modules: USB generic driver
Move the usb_complete_callback() compatibility wrapper out of the
kernel tree.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
Move the usb_pipe_needs_resubmit() compatibility wrapper out of the
kernel tree.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
Add more comments about other device modes and unsupported devices to
the Roland part of the quirks table.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
Add a quirk entry for the Hercules DJ Console to ignore timeouts on
some mixer control transfers.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: USB generic driver
Simplify the handling of MIDI quirks by treating an interface without
quirks as a QUIRK_MIDI_STANDARD_INTERFACE.
This also fixes the bug where a MIDI_STANDARD quirk would not be
recognized.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
USB generic driver
Add a quirk entry for the external MIDI ports of the
Windows Edition of the Hercules DJ Console.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
USB generic driver
Add a mixer quirk entry for the Hercules DJ Console (Windows Edition)
that uses a different USB product ID.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
USB generic driver
Increase the maximum PCM buffer size to 1 MB. The USB driver doesn't
have any inherent buffer size limit, and big multichannel interfaces
may benefit from this.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
USB generic driver
There is another revision of the PHASE26 with a different product ID;
add a quirk entry for that, too.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
USB generic driver
Add a quirk entry for the Roland RD-700SX.
This should work for the RD-300SX, too.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
USB generic driver
Add a quirk entry for the Hercules DJ Console to ignore timeouts on
some mixer control transfers.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
USB generic driver
Add the SNDRV_PCM_INFO_BATCH flag to the PCM hardware information to
indicate that the driver uses double buffering.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
29 July 2005, Cambridge, MA:
This afternoon Alan Stern submitted a patch to remove the URB_ASYNC_UNLINK
flag from the Linux kernel. Mr. Stern explained, "This flag is a relic
from an earlier, less-well-designed system. For over a year it hasn't
been used for anything other than printing warning messages."
An anonymous spokesman for the Linux kernel development community
commented, "This is exactly the sort of thing we see happening all the
time. As the kernel evolves, support for old techniques and old code can
be jettisoned and replaced by newer, better approaches. Proprietary
operating systems do not have the freedom or flexibility to change so
quickly."
Mr. Stern, a staff member at Harvard University's Rowland Institute who
works on Linux only as a hobby, noted that the patch (labelled as548) did
not update two files, keyspan.c and option.c, in the USB drivers' "serial"
subdirectory. "Those files need more extensive changes," he remarked.
"They examine the status field of several URBs at times when they're not
supposed to. That will need to be fixed before the URB_ASYNC_UNLINK flag
is removed."
Greg Kroah-Hartman, the kernel maintainer responsible for overseeing all
of Linux's USB drivers, did not respond to our inquiries or return our
calls. His only comment was "Applied, thanks."
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB generic driver
When a USB error occurs that might indicate that the device has been
unplugged, don't resubmit the URB immediately to prevent flooding the
log with error messages before khubd has us disconnect()ed.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
USB generic driver
Emagic devices pad their packets not with 0xff bytes but with a 0xff
byte followed by garbage, so we have to stop at the first such byte.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Jaroslav Kysela
Clemens Ladisch
Nishanth Aravamudan
Takashi Iwai
Al Viro
Alan Stern