asynchronous. I realize that this means the custom application will
not work as written, but it is not okay to break most users of ugen(4).
The major problem is that a bulk read transfer is not an interrupt
saying that X bytes are available -- it is a request to be able to
receive up to X bytes, with T timeout, and S short-transfer-okayness.
The timeout is a software mechanism that ugen(4) provides and cannot
be implemented using asynchronous reads -- the timeout must start at
the time a read is done.
The status of up to how many bytes can be received in this transfer
and whether a short transfer returns data or error is also encoded
at least in ohci(4)'s requests to the controller. Trying to detect
the "maximum width" results in using a single buffer of far too
small when an application requests a large read.
Even if you combat this by replacing all buffers again with the
maximal sized read buffer (1kb) that ugen(4) would allow you to
use before, you don't get the right semantics -- you have to
throw data away or make all the timeouts invalid or make the
short-transfer settings invalid.
There is no way to do this right without extending the ugen(4) API
much further -- it breaks the USB camera interfaces used because
they need a chain of many maximal-width transfers, for example, and
it makes cross-platform support for all the BSDs gratuitously hard.
Instead of trying to do select(2) on a bulk read pipe -- which has
neither the information on desired transfer length nor ability to
implement timeout -- an application can simply use a kernel thread
and pipe to turn that endpoint into something poll-able.
It is unfortunate that bulk endpoints cannot provide the same semantics
that interrupt and isochronous endpoints can, but it is possible to just
use ioctl(USB_GET_ENDPOINT_DESC) to find out when different semantics
must be used without preventing the normal users of the ugen(4) device
from working.
data endpoints. The control endpoint doesn't need read/write/poll
operations, and more importantly, the thread counts should be
separate so that the control endpoint can properly reference itself
while deleting and recreating the data endpoints.
* Add some macros that handle referencing/releasing devices, and use them
for sleeping/woken-up and open/close operations as apppropriate.
* Use d_purge for FreeBSD, and a loop testing the open status for all
the endpoints for NetBSD and OpenBSD, so that when the device is
detached, the right thing always happens.
restart the current waiting transfer. If this isn't done, the device's
next transfer (that we would like to do a short read on) is going to
return an error -- for short transfer.
* For bulk transfer endpoints, restore the maximum transfer length each
time a transfer is done, or the first short transfer will make all the
rest that size or smaller.
* Remove impossibilities (malloc(M_WAITOK) == NULL, &var == NULL).
select(2), and discovered to my horror that ugen(4)'s bulk in/out support
is horribly lobotomized. Bulk transfers are done using the synchronous
API instead of the asynchronous one. This causes the following broken
behavior to occur:
- You open the bulk in/out ugen device and get a descriptor
- You create some other descriptor (socket, other device, etc...)
- You select on both the descriptors waiting until either one has
data ready to read
- Because of ugen's brokenness, you block in usb_bulk_transfer() inside
ugen_do_read() instead of blocking in select()
- The non-USB descriptor becomes ready for reading, but you remain blocked
on select()
- The USB descriptor becomes ready for reading
- Only now are you woken up so that you can ready data from either
descriptor.
The result is select() can only wake up when there's USB data pending. If
any other descriptor becomes ready, you lose: until the USB descriptor
becomes ready, you stay asleep.
The correct approach is to use async bulk transfers, so I changed
the read code to use the async bulk transfer API. I left the write
side alone for now since it's less of an issue.
Note that the uscanner driver has the same brokenness in it.
produced better results for a test program I had here, it didn't
substantially change the number of crashes that I saw. Both the old
code and the new code seemed to produce the same crashes from the usb
layer. Since the new code also solves a close() crash, go with it
until the underlying issues wrt devices going away can be addressed.
The reference counts are there to block detach until the sleepers in
read/write/ioctl have gotten out, not to prevent the open device from
going away. Restore the old behavior so that we have a chance to wake
up sleepers when the usb device goes away, so they can properly return
EIO back to the caller when this happens.
Otherwise, we have a guarnateed panic waiting to happen when a device
detaches with an active read channel.
This should be merged to 5 asap.
operations when the refcount doesn't protect the opens and closes. Fix
this, and don't actually let a time out happen: now ugen(4) devices do
not get freed out from under the programs with them open.
uhid.c (1.61), author: jdolecek
add support for USB_GET_DEVICEINFO and USB_GET_STRING_DESC ioctls,
with same meaning as for ugen(4)
usbdi_util.h (1.29), usb_quirks.c (1.50), uhid.c (1.62),
ugen.c (1.68), usb_subr.c (1.114) author: mycroft
Yes, some devices return incorrect lengths in their string
descriptors. Rather than losing, do what Windows does: just
request the maximum size, and allow a shorter response. Obsoletes
the need for UQ_NO_STRINGS, and therefore these "quirks" are removed.
usb_subr.c (1.116), author: mycroft
In the "seemed like a good idea until I found the fatal flaw"
department... Attempting to read a maximum-size string descriptor
causes my kue device to go completely apeshit. So, go back to the
original method, but allow the device to return a shorter string than
it claimed.
Obtained from: NetBSD
Introduce d_version field in struct cdevsw, this must always be
initialized to D_VERSION.
Flip sense of D_NOGIANT flag to D_NEEDGIANT, this involves removing
four D_NOGIANT flags and adding 145 D_NEEDGIANT flags.
Free approx 86 major numbers with a mostly automatically generated patch.
A number of strategic drivers have been left behind by caution, and a few
because they still (ab)use their major number.
thread being waken up. The thread waken up can run at a priority as
high as after tsleep().
- Replace selwakeup()s with selwakeuppri()s and pass appropriate
priorities.
- Add cv_broadcastpri() which raises the priority of the broadcast
threads. Used by selwakeuppri() if collision occurs.
Not objected in: -arch, -current
even could call VOP_REVOKE() on vnodes associated with its dev_t's
has originated, but it stops right here.
If there are things people belive destroy_dev() needs to learn how to
do, please tell me about it, preferably with a reproducible test case.
Include <sys/uio.h> in bluetooth code rather than rely on <sys/vnode.h>
to do so.
The fact that some of the USB code needs to include <sys/vnode.h>
still disturbs me greatly, but I do not have time to chase that.
This fixes net/pppoa port for Alcatel Speedtouch devices.
Submitted by: Jay Cornwall <jay@evilrealms.net>
Tested by: Francois Rogler <francois@rogler.org>
Approved by: re (scottl)
branches:
Initialize struct cdevsw using C99 sparse initializtion and remove
all initializations to default values.
This patch is automatically generated and has been tested by compiling
LINT with all the fields in struct cdevsw in reverse order on alpha,
sparc64 and i386.
Approved by: re(scottl)
debugging levels to off by default. Now that debug levels can be
tweaked by sysctl we don't need to go through hoops to get the
different usb parts to produce debug data.
that the attach succeeded. (Fixes a potential panic for devices
that fail to attach properly and are subsquently unplugged and then
plugged back in again.)
usbdi.h (1.60)
(and local changes compatibility changes to ufm.c and urio.c)
date: 2002/02/11 15:11:49; author: augustss;
Give usbd_do_request_flags() an extra argument for the timeout.
