labeled disk.
This is complicated by the fact that BBSIZE is greater than the
PAGE_SIZE limit ioctl inflicts on arguments which are automatically
copied in.
As long as we don't need access to userland memory (copyin/out) we
can deal with the ioctl using g_callme() which executes it from the
GEOM event thread.
Once we need copyin/out, we need to return the bio with EDIRIOCTL
in order to make geom_dev call us back in the original process context
where copyin will work.
Unfortunately, that results in us getting called with Giant, so
we have to DROP_GIANT/PICKUP_GIANT around the code where we diddle
GEOMs internals.
Sometimes you just can't win...
... But it does make geom_bsd.c an almost complete example of the
GEOM beastiarium.
data structure called kse_upcall to manage UPCALL. All KSE binding
and loaning code are gone.
A thread owns an upcall can collect all completed syscall contexts in
its ksegrp, turn itself into UPCALL mode, and takes those contexts back
to userland. Any thread without upcall structure has to export their
contexts and exit at user boundary.
Any thread running in user mode owns an upcall structure, when it enters
kernel, if the kse mailbox's current thread pointer is not NULL, then
when the thread is blocked in kernel, a new UPCALL thread is created and
the upcall structure is transfered to the new UPCALL thread. if the kse
mailbox's current thread pointer is NULL, then when a thread is blocked
in kernel, no UPCALL thread will be created.
Each upcall always has an owner thread. Userland can remove an upcall by
calling kse_exit, when all upcalls in ksegrp are removed, the group is
atomatically shutdown. An upcall owner thread also exits when process is
in exiting state. when an owner thread exits, the upcall it owns is also
removed.
KSE is a pure scheduler entity. it represents a virtual cpu. when a thread
is running, it always has a KSE associated with it. scheduler is free to
assign a KSE to thread according thread priority, if thread priority is changed,
KSE can be moved from one thread to another.
When a ksegrp is created, there is always N KSEs created in the group. the
N is the number of physical cpu in the current system. This makes it is
possible that even an userland UTS is single CPU safe, threads in kernel still
can execute on different cpu in parallel. Userland calls kse_create to add more
upcall structures into ksegrp to increase concurrent in userland itself, kernel
is not restricted by number of upcalls userland provides.
The code hasn't been tested under SMP by author due to lack of hardware.
Reviewed by: julian
functions implemented approximately the same limits on fragment memory
usage, but in different fashions.)
End user visible changes:
- Fragment reassembly queues are freed in a FIFO manner when maxfragpackets
has been reached, rather than all reassembly stopping.
MFC after: 5 days
potential discontinuities in our UTC timescale.
Applications can monitor this variable if they want to be informed
about steps in the timescale. Slews (ntp and adjtime(2)) and
frequency adjustments (ntp) will not increment this counter, only
operations which set the clock. No attempt is made to classify
size or direction of the step.
IP fast forwarding, SIOCGIFADDR, setting hardware address (not currently
enabled in cm driver), multicasts (experimental)
- add ARC_MAX_DATA, use IF_HANDOFF, remove arc_sprintf() and some unused
variables
- if_simloop logic is made more similar to ethernet
- drop not ours packets early (if we are not in promiscous mode)
Submitted by: mark tinguely (partially)
commands from below the first 8K of physical memory. A better fix
is to modify the busdma api to allow either inclusion ranges or
multiple exclusion ranges, but that debate is for another day.
MFC After: 2 days
parent device, if there is a parent configured. Modify the result
returned by the parent to indicate that the only supported media
is the currently configured one.
Reviewed by: brooks
to mount_nfs. The sysctl defaults to 1 (paranoid mode). Setting it to 0
will allow an NFS client to receive replies on a different IP then they
were sent to by default.
Submitted by: Sean Eric Fagan <sef@kithrup.com>
- Sort definition of cpu_* variables appropriately.
- Move cpu_fxsr out of the magic non-BSS set of variables and stick it in
the BSS along with hw_instruction_sse (make the latter static as well).
Submitted by: bde (partially)
variable to something in the cpu_* namespace since that's what all the
other cpuid variables were named and cpu_procinfo is what I came up with.
Requested by: bde
correctly against PF_LOCAL. It seems that the test always fails then
sockaddr was not filled. So, I added else clause for workaround.
I doubt if it is right fix. However, it is better than nothing. I
found that NetBSD has same potential problem. But, fortunately,
NetBSD has equivalent else clause.
MFC after: 1 week
1.) Fix an off-by-one in the DVMA space handling, which would make it
possible to allocate one page beyond the end of the DVMA area.
This page was aliased to the first page. Apparently, this bug was
responsible for the trashed nvram/eeprom some people were reporting,
in conjunction with a number of unfortunate coincidences.
2.) Fix broken boundary and and lowaddr calculations.
3.) Fix a memory leak on an error path.
4.) Update a outdated comment to reflect the introduction of IOMMU_MAX_PRE,
make the usage of IOMMU_MAX_PRE more consistent and KASSERT that the
preallocation size is not 0.
5.) Fix a case where an error return was lost.
6.) When signalling an error to the caller by invoking the callback, do
not use a segment pointer of NULL for compatability with existing
drivers.
Also, increase the maximum segment number to 64; it is rather arbitrary,
with the exception of the of the stack space consumed by the segment
array.
Special thanks go to Harti Brandt <brandt@fokus.fraunhofer.de> for
spotting 4 and 5, and testing many iterations of patches.
Pointy hats to: tmm
- Remove NetBSD-style or-ed together BUS_DMASYNC operations, in some
cases relaxing the (intended) syncing operation a bit.
- Add syncs before reading the descriptor rings.
- Try to combine syncs where possible to avoid overhead.
- Sync all maps before unloading them.
- Remove NetBSD-style or-ed together BUS_DMASYNC operations, in some
cases relaxing the (intended) syncing operation a bit.
- Stop pretending that that we can sync part of a dmamap: replace the
GEM_CDTXSYNC and GEM_CDRXSYNC macros with GEM_CDSYNC to sync the
complete control map, and combine syncs wherever possible to avoid
the overhead.
- Sync all maps before unloading them.
- Remove a few syncs which should be unnecessary.
constants where flag bits (as in NetBSD), although they are consecutively
numbered in FreeBSD. This would cause unnecessary flushing in the
BUS_DMASYNC_POSTWRITE case, but was otherwise mostly harmless.
indicate that uma_small_alloc should not. This code should be refactored so
that there is not so much cross arch duplication.
Reviewed by: jake
Spotted by: tmm
Tested on: alpha, sparc64
Pointy hat to: jeff and everyone who cut and pasted the bad code. :-)
1. eliminate unnecessary loop which frees and re-allocates
the just allocated array
2. eliminate the newsize recomputation
3. eliminate unnecessary unlock and relock around free
4. correctly match the free with the malloc into M_KQUEUE instead of M_TEMP
5. eliminate conditional assignment of oldlist, which is equivalent to a
simple assignment
6. eliminate the oldlist temporary variable completely
Reviewed by: jhb
metadata. This fixes module dependency resolution by the kernel linker on
sparc64, where the relocations for the metadata are different than on other
architectures; the relative offset is in the addend of an Elf_Rela record
instead of the original value of the location being patched.
Also fix printf formats in debug code.
Submitted by: Hartmut Brandt <brandt@fokus.gmd.de>
PR: 46732
Tested on: alpha (obrien), i386, sparc64
at which tx errors are printed (default to 0); hw.wi.debug control the debug
msgs and is only present when WI_DEBUG is defined at compile time (the default
for the moment)
Requested by: imp
Add a constant for the controller's stack size and the
maximum scsi offset.
aic7xxx.seq:
Style nit. The source is implied to be the destination
unless overridden in an "and" instruction.
Update target mode code for changes in identify seen
sequencer flags.
aic7xxx_pci.c:
Ensure that the PCIERRGENDIS bit is set in the
PCIERRGEN config space register. Perhaps this
is a reason for the spurios parity errors reported
on U160 controllers.
Honor the AHC_NO_BIOS_INIT flag.
Allow PCI interrupt reporting to be disabled,
by clearing the PERRRESEN bit in the command
register. This option is now enabled via a new
softc flag: AHC_DISABLE_PCI_PERR.
Disable SERR and pause the controller prior to performing
our mmapped I/O test. This should handle the case of
controllers that do not "auto-access pause". For legacy
controllers, use SCB ram instead of scratch ram since
the latter may contain settings left over from the BIOS
that we will use if an seeprom is not found.
Make use of new ahc_inl/outl() inlines.
aic7xxx.h:
Reformat a few comments to follow driver style.
Add a controller flags that indicate that a controller
has not been initialized by the BIOS and whether to
disable PCI parity errors..
Remove stack probing softc members.
Add a few more syncrate constants that are useful in speed
fallback calculations.
Add the SHOW_MASKED_ERRORS debug flag.
aic7xxx.h:
aic7xxx.c:
Implement the SCB_SILENT flag. This is useful for
hushing up the driver during DV or other operations
that we expect to cause transmission errors. The
messages will still print if the SHOW_MASKED_ERRORS
debug option is enabled.
aic7xxx_inline.h:
Implement ahc_[in|out][w|l|q]. This removes the need
for manual 'or and shift" type operations throughout
the driver.
aic7xxx.c:
Move SELTO dignostic so that the SCB is still valid
when we use it for printing path information.
If we are narrow, limit syncrate to Ultra2.
Don't clobber ppr_options when forcing a renegotiation.
The current ppr_options may be referenced while queuing
new commands. Don't set our width to unknown when forcing
negotiation on narrow controllers. This will confuse the
negotiation code into negotiating with a wide message on
narrow controllers.
Add an "asserting atn" diagnostic with controller/target
information.
Remove the probe_stack code. The stack is always
4 deep on legacy controllers, so probing is pointless.
This also avoids an issue where probing the stack would
upset the aic7770.
In ahc_reset(), record whether or not we found the
controller in a reset state. If the controller was
already reset, assume that no BIOS has initialized
the controller and ignore left over scratch ram
settings.
Fix an ifdef bug that caused sequencer debugging to
be enabled always.
Clear the ultraenb flag in our tstate during startup.
The ultraenbled'ness of a device is recorded in the user
transfer settings. tstate->ultraenb bitmask indicates
which devices we have negotiated an ultra speed with.
Just after initialization, we are async. Setting the
ultraenb flag while async seems to be harmless, but it
was confusing to see the ULTRAENB flag set in the SCB.
Enhance residual diagnostic to indicate if the residual
if for sense information or normal data transfers.
Indicate the features, bugs, and flags set in the softc
that are used to control firmware patch download when
booting verbose.
In ahc_dump_card_state() fix a logic reversal. The
SCSIPHASE register only exists on U160 controllers.
The SCSISIGI register exists on all controllers. Not
the other way around. Also print out the ERROR register.
Allow ahc_dump_card_state() to be called when the sequencer
is not paused. Add dump card state markers as in the U320
driver.
Implement the SCB_SILENT flag. This is useful for
hushing up the driver during DV or other operations
that we expect to cause transmission errors. The
messages will still print if the SHOW_MASKED_ERRORS
debug option is enabled.
Save and restore the NEGOADDR address when setting
new transfer settings. The sequencer performs lookups
in the negotiation table too and it expects NEGOADDR
to remain consistent across pause/unpause sessions.
Consistently use "offset" instead of "period" to determine
if we are running sync or not.
Add a SHOW_MESSAGES diagnostic for when we assert ATN
during message processing.
Print out IU, QAS, and RTI features when showing transfer options.
Limit the syncrate after all option conformance
changes have taken place in ahd_devlimited_syncrate.
Changes in options may change the final syncrate we
accept.
Keep a copy of the hs_mailbox in our softc so that
we can perform read/modify/write operations on the
hs_mailbox without having to pause the sequencer to
read the last written value. Use the ENINT_COALESS
flag in the hs_mailbox to toggle interrupt coalessing.
Add entrypoints for enabling interrupt coalessing and
setting both a timeout (how long to wait for commands
to be coalessed) and a maximum commands to coaless value.
Add a statistics timer that decides when to enable or
disable interrupt coalessing based on load.
Add a routine, ahd_reset_cmds_pending() which is used
to update the CMDS_PENDING sequencer variable whenever
error recovery compeltes SCBs without notifying the
sequencer. Since ahd_reset_cmds_pending is called
during ahd_unpause() only if we've aborted SCBs, its
call to ahd_flush_qoutfifo should not cause recursion
through ahd_run_qoutfifo(). A panic has been added to
ensure that this recursion does not occur.
In ahd_search_qinfifo, update the CMDS_PENDING sequencer
variable directly. ahd_search_qinififo can be called
in situations where using ahd_reset_cmds_pending() might
cause recursion. Since we can safely determine the
exact number to reduce CMDS_PENDING by in this scenario
without running the qoutfifo, the manual update is sufficient.
Clean up diagnostics.
Add ahd_flush_qoutfifo() which will run the qoutfifo
as well as complete any commands sitting on the
sequencer's COMPLETE_SCB lists or the good status FIFO.
Use this routine in several places that did similar
things in an add-hoc, but incomplete, fashion. A call
to this routine was also added to ahd_abort_scbs() to
close a race.
In ahd_pause_and_flushwork() only return once selections
are safely disabled. Flush all completed commands via
ahd_flush_qoutfifo().
Remove "Now packetized" diagnostic now that this
information is incorperated into the actual negotiation
messages that are displayed.
When forcing renegotiation, don't clober the current
ppr_options. Much of the driver uses this information
to determine if we are currently packetized or not.
Remove some stray spaces at column 1 in ahd_set_tags.
When complaining about getting a host message loop
request with no pending messages, print out the
SCB_CONTROL register down on the card.
Modify the ahd_sent_msg() routine to handle a search
for an outgoing identify message. Use this to detect
a msg reject on an identify message which typically
indicates that the target thought we were packetized.
Force a renegotiation in this case.
In ahd_search_qinfifo(), wait more effectively for SCB
DMA activities to cease. We also disable SCB fetch
operations since we are about to change the qinfifo
and any fetch in progress will likely be invalidated.
In ahd_qinfifo_count(), fix the qinfifo empty case.
In ahd_dump_card_state(), print out CCSCBCTL in the
correct mode.
If we are a narrow controller, don't set the current
width to unknown when forcing a future negotiation.
This just confuses the code into attempting a wide
negotiation on a narrow bus.
Add support for task management function completions.
Modify ahd_handle_devreset so that it can handle
lun resets in addition to target resets. Use
ahd_handle_devreset for lun and target reset task
management functions.
Handle the abort task TMF race case better. We now
wait until any current selections are over and then
set the TMF back to zero. This should cause the sequencer
to ignore the abort TMF completion should it occur.
Correct a bug in the illegal phase handler that
caused us to drop down to narrow when handling the
unexpected command phase case after 3rd party
reset of a packetized device.
Indicate the features, bugs, and flags set in the softc
that are used to control firmware patch download when
booting verbose.
aic79xx.h:
Add coalessing and HS_MAILBOX fields.
Add per-softc variables for the stats "daemon".
Add a debug option for interrupt coalessing activities.
Add two new softc flags:
o AHD_UPDATE_PEND_CMDS
Run ahd_reset_cmds_pending() on the next unpause.
o AHD_RUNNING_QOUTFIFO
Used to catch recursion through ahd_run_qoutfifo().
aic79xx.reg:
Correct register addresses related to the software timer
and the DFDBCTL register.
Add constants paramaterizing the software timer.
Add scratch ram locations for storing interrupt coalessing
tunables.
Break INTMASK in SEQITNCTL out into INTMASK1 and INTMASK2.
In at least the REV A, these are writable bits. We make
use of that for a swtimer workaround in the sequencer.
Since HS_MAILBOX autoclears, provide a sequencer variable
to store its contents.
Add SEQINT codes for handling task management completions.
aic79xx.seq:
Correct ignore wide residue processing check for
a wide negotiation being in effect. We must be
in the SCSI register window in order to access the
negotiation table.
Use the software timer and a commands completed count to
implement interrupt coalessing. The command complete is
deferred until either the maximum command threshold or a
the expiration of a command deferral timer. If we have
more SCBs to complete to the host (sitting in COMPLETE_SCB
lists), always try to coaless them up to our coalessing limit.
If coalessing is enabled, but we have fewer commands oustanting
than the host's min coalessing limit, complete the command
immediately.
Add code to track the number of commands outstanding.
Commands are outstanding from the time they are placed
into the execution queue until the DMA to post completion
is setup.
Add a workaround for intvec_2 interrupts on the H2A4.
In H2A4, the mode pointer is not saved for intvec2, but
is restored on iret. This can lead to the restoration
of a bogus mode ptr. Manually clear the intmask bits and
do a normal return to compensate. We use intvec_2 to
track interrupt coalessing timeouts.
Since we cannot disable the swtimer's countdown, simply
mask its interrupt once we no longer care about it firing.
In idle_loop_cchan, update LOCAL_HS_MAILBOX everytime
we are notified of an HS_MAILBOX update via the
HS_MAILBOX_ACT bit in QOFF_CTLSTA. We have to use a
local copy of persistant portions of the HS_MAILBOX as
the mailbox auto-clears on any read.
Move the test for the cfg4istat interrupt up an instruction
to hopefully close a race between the next outgoing selection
and our disabling of selections.
Add a missing ret to the last instruction in load_overrun_buf.
Add notifications to the host of task management
completions as well as the completions for commands
that completed successfully before their corresponding
TMF could be sent.
Hold a critical section during select-out processing
until we have a fully identified connection. This
removes a race condition with the legacy abort handler.
Correct a few spelling errors in some comments.
aic79xx_inline.h:
Call ahd_reset_cmds_pending() in ahd_unpause if required.
Update cmdcmplt interrupt statistics in our interrupt
handler.
Allow callers to ahd_send_scb() to set the task management
function.
aic79xx_pci.c:
Disable SERR and pause the controller prior to performing
our mmapped I/O test. The U320 controllers do not support
"auto-access-pause".
aic79xx_osm.c:
Set the task management function now that
ahd_send_scb() doesn't do it for us. We
also perform a lun reset in response to BDR
requests to packetized devices.
and set the link type for use by libpcap and tcpdump
o move mtx unlock in bpfdetach up; it doesn't need to be held so long
o change printf in bpf_detach to distinguish it from the same one in bpfsetdlt
Note there are locking issues here related to ioctl processing; they
have not been addressed here.
Submitted by: Guy Harris <guy@alum.mit.edu>
Obtained from: NetBSD (w/ locking modifications)
the bootcode. I don't think there acturally are any extended partitions on
pc98, and this define may merely help cover up the fact that the biosdisk.c
was insufficiently scrubbed when copy&pasted from i386.
conversion. The new version has improved interpolation accuracy and
maintains the timing relationship between the input and output signals
exactly.
Approved by: cg
CAUTION:
Previously CCD would be different from all other disks in
the system in that there were no "ccd0" device, only a
"ccd0c" device.
This is no longer so after this commit. If you access a
ccd device through the "/dev/ccd0c" device _and_ have not
actually put a BSD disklabel on the device, you will have
to use the name "/dev/ccd0". If your CCD device contains
a BSD disklabel there should be no difference.
You need to recompile ccdconfig(8) using the changed
src/sys/sys/ccdvar.h for the -g "show me" option to work.
I have run the regression test I created before I started
overhauling CCD and it flags no problems, but this code
is mildly evil, so take care. If you would cry if you lost
what's on CCD, make a back before you upgrade.
Create separate cdevsw for the /dev/ccd.ctl device.
Remove the cloning function, the disk-minilayer will do all naming
for us.
Remove the ccdunit and ccdpart functions and carry the softc pointer
in the relevant dev_t's and structures.
Release all memory when a CCD device is unconfigured, previously
the softc would linger behind.
Remove all traces of BSD disklabel fiddling code.
Remove ccdpsize, the disk mini-layer does this for us.
Don't allocate memory with M_WAITOK in ccdstrategy().
Remove boundary checks which the disk mini-layer does for us.
Don't allocate space for more than 2 ccdbuf, RAID was never implemented.
NB: I have not tried to address any of the preexisting ailments of CCD.
and can be added back selectively, should anybody start to interest
themselves for the internal workings of ccd.
This commit will make the diffs for the following commits much more
readable.
was used to control code which were conditional on DEVFS' precense
since this avoided the need for large-scale source pollution with
#include "opt_geom.h"
Now that we approach making DEVFS standard, replace these tests
with an #ifdef to facilitate mechanical removal once DEVFS becomes
non-optional.
No functional change by this commit.
more than return ENXIO from its open routine, so most of this file
is unneeded.
A straight #ifdef'ing would look quite messy, and make the file
quite unreadable, so instead I have simply added the DEVFS version
of the file at the top, protected by #ifndef NODEVFS.
Once we have removed NODEVFS option, we can retain 86 the 86 lines at
the top and drop the other 287 lines.
This allows me to mark code which they control with #ifdef without
polluting files with #includes of opt_devfs.h and opt_geom.h.
Once these two options are removed, this will allow mechanical removal
of the bits their removal makes obsolete.
<machine/ieeefp.h> where it belongs.
o Remove the i386 specific inclusion of <machine/floatingpoint.h>
from <ieeefp.h>, now that including <machine/ieeefp.h> is enough
for all architectures.
o Allow <machine/ieeefp.h> to inline the functions exposed by the
headers by checking for _IEEEFP_INLINED_ in the MI header. When
defined, prototypes are not given and it is assumed that the MD
headers, when inlining only a subset of the functions provide
prototypes for the functions not being inlined.
Based on patch from: Terry Lambert <tlambert2@mindspring.com>
Tested with: make release.
- Add conversions to/from little endian for fields that the NIC accesses
by DMA as required.
- Add some bus_dmamap_sync() calls, and correct some existing ones.
- Read the receiver information from the EEPROM in an endian-neutral
manner.
- Load all RX and TX descriptors in a single DMA map up front, and
get the bus addresses of individual descriptors by address arithmetic;
this fixes multiple use of the descriptor tags, which would have
undesired effects.
It seems that xl still does not work on e250 boxen, for reasons which
are not clear yet.
Reviewed by: mux
yet that depend on it because sio(4) needs support for it before it
can be used. There's no reason why zs(4) couldn't attach to puc(4)
in the (near?) future (in principle), so don't make memory mapped I/O
support in sio(4) a precondition for this change.
NULL. union_whiteout() expects the componentname argument to be non-NULL.
Fixes a NULL dereference panic when an existing union mount becomes the
upper layer of a new union mount.
SS_ISCONNECTING state, returning EINVAL (which is what POSIX mandates
in this case).
listen() on connected or connecting sockets would cause them to enter
a bad state; in the TCP case, this could cause sockets to go
catatonic or panics, depending on how the socket was connected.
Reviewed by: -net
MFC after: 2 weeks
the three configuration ioctls which need a unit number.
Add a "ccd.ctl" device for config operations.
Implement ioctls on ccd.ctl which rely on the explicityly passed
unit numbers.
Update ccdconfig to use the new ccd.ctl interface.
Add code to the kernel to detect old ccdconfig binaries, and whine
about it.
Add code to ccdconfig to detect old kernels, and whine about it.
These two compatibility measures will be retained only for a limited
period since they are in the way of GEOM'ification of ccd.
Interface (SMAPI) BIOS, which is present on some IBM
Thinkpad models (560, 600, 770 to name a few.)
The SMAPI BIOS provides access to System Information,
System Configuration, and Power Management.
vm_pageout_deficit:
1. Update vm_pageout_deficit before VM_WAIT. There is no sense in
delaying the update; the sooner the pageout daemon receives this
information the better. Reviewed by: tegge
2. Update vm_pageout_deficit according to the number of pages still
needed to complete the allocation, not the original size of the
allocation. Submitted by: tegge
(These errors have existed since the introduction of vm_pageout_deficit
in revision 1.144.)
* Fix a bug where devices weren't cleaned up on close(): CAM_REQ_CMP != 0
user:
* Increase timeout in usermode to CAM_TIME_INFINITY. The initiator is in
charge of timeouts and the value was in ms, not seconds.
* Bring two debugging printfs under the debug flag
* Clean up man page to show increased testing on isp(4)
Submitted by: gibbs (bugfixes)
portable copy. Note that pmap_extract() must be used instead of
pmap_kextract().
This is precursor work to a reorganization of vmapbuf() to close remaining
user/kernel races (which can lead to a panic).
frequency in Hz. The default is still 33.333 MHz. Please notice
that the number is round to a multiple of four internally so it may
not read back exactly the same as written.
Add compile time ELAN_XTAL option to override the 33.333 MHz default.
Add compile time ELAN_PPS option to enable code for high precision
(250 nanoseconds) timestamping of external signals.
state machine to provide station and host ap functionality for drivers.
More work will follow to split out the state machine and protocol
support from the ioctl interfaces to ease portability/sharing with
NetBSD and forthcoming ports to other systems.
Reviewed by: imp
Obtained from: NetBSD (originally)
descriptor request, which usbd_get_string_desc() uses to get the
length of a descriptor. One device for instance returns a full 8
byte long packet instead which confuses the rest of the stack and
leads to the USB port being reset. The fix is to instead request
two bytes, but not to complain if we only get one.
Submitted by: kan
MFC after: 3 days
