Commit Graph

228485 Commits

Author SHA1 Message Date
John Baldwin
b501cc5da6 Rework pathconf handling for FIFOs.
On the one hand, FIFOs should respect other variables not supported by
the fifofs vnode operation (such as _PC_NAME_MAX, _PC_LINK_MAX, etc.).
These values are fs-specific and must come from a fs-specific method.
On the other hand, filesystems that support FIFOs are required to
support _PC_PIPE_BUF on directory vnodes that can contain FIFOs.
Given this latter requirement, once the fs-specific VOP_PATHCONF
method supports _PC_PIPE_BUF for directories, it is also suitable for
FIFOs permitting a single VOP_PATHCONF method to be used for both
FIFOs and non-FIFOs.

To that end, retire all of the FIFO-specific pathconf methods from
filesystems and change FIFO-specific vnode operation switches to use
the existing fs-specific VOP_PATHCONF method.  For fifofs, set it's
VOP_PATHCONF to VOP_PANIC since it should no longer be used.

While here, move _PC_PIPE_BUF handling out of vop_stdpathconf() so that
only filesystems supporting FIFOs will report a value.  In addition,
only report a valid _PC_PIPE_BUF for directories and FIFOs.

Discussed with:	bde
Reviewed by:	kib (part of a larger patch)
MFC after:	1 month
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D12572
2017-12-19 22:39:05 +00:00
Stephen Hurd
ff46fd16e5 Add log messages for unknown and unhandled phy types
Previously, it silently only supported auto, instead, log a message
indicating why only auto is supported.

Submitted by:	Bhargava Chenna Marreddy <bhargava.marreddy@broadcom.com>
Sponsored by:	Broadcom Limited
Differential Revision:	https://reviews.freebsd.org/D13358
2017-12-19 22:15:46 +00:00
Stephen Hurd
a0b660301a On Link up & down, update media types
It's possible to change the SFP module when link is down, which would
change the available media types.  This is part of D13358.

Submitted by:	Bhargava Chenna Marreddy <bhargava.marreddy@broadcom.com>
Sponsored by:	Broadcom Limited
2017-12-19 22:06:25 +00:00
Stephen Hurd
980da9f2f0 Support short HWRM commands
New Stratus bnxt devices require support for short HWRM commands for VFs
to function.  Enable their use, but only use them if it's both supported
and required... prefer the long HWRM commands when possible.

Submitted by:	Bhargava Chenna Marreddy <bhargava.marreddy@broadcom.com>
Sponsored by:	Broadcom Limited
Differential Revision:	https://reviews.freebsd.org/D13269?id=36180
2017-12-19 21:07:30 +00:00
Stephen Hurd
6a0dc418a6 Don't populate NVRAM sysctls for VFs
Only the PF allows NVRAM interaction on bnxt devices.

Submitted by:	Bhargava Chenna Marreddy <bhargava.marreddy@broadcom.com>
Sponsored by:	Broadcom Limited
2017-12-19 20:32:45 +00:00
John Baldwin
35b1a3abd3 Update tmpfs link count handling for ino64.
Add a new TMPFS_LINK_MAX to use in place of LINK_MAX for link overflow
checks and pathconf() reporting.  Rather than storing a full 64-bit
link count, just use a plain int and use INT_MAX as TMPFS_LINK_MAX.

Discussed with:	bde
Reviewed by:	kib (part of a larger patch)
Sponsored by:	Chelsio Communications
2017-12-19 20:19:07 +00:00
John Baldwin
c24008cc39 Honor NANDFS_LINK_MAX for post-ino64.
This uses NANDFS_LINK_MAX instead of LINK_MAX for link overflow checks
and the value reported by pathconf() / fpathconf().

Sponsored by:	Chelsio Communications
2017-12-19 20:17:07 +00:00
John Baldwin
f6e25ec77c Report INT_MAX for LINK_MAX for devfs' VOP_PATHCONF().
devfs uses int's for link counts internally and already reports the the
full link count via stat() post ino64.

Sponsored by:	Chelsio Communications
2017-12-19 20:07:57 +00:00
John Baldwin
a74da9fb83 Use FUSE_LINK_MAX for LINK_MAX in fuse' VOP_PATHCONF().
Should have included this in r326993.

MFC after:	1 month
Sponsored by:	Chelsio Communications
2017-12-19 19:57:55 +00:00
John Baldwin
418e621276 Handle _PC_FILESIZEBITS and _PC_SYMLINK_MAX for devfs' VOP_PATHCONF().
MFC after:	1 month
Sponsored by:	Chelsio Communications
2017-12-19 19:53:34 +00:00
John Baldwin
599afe53a8 Move NAME_MAX, LINK_MAX, and CHOWN_RESTRICTED out of vop_stdpathconf().
Having all filesystems fall through to default values isn't always correct
and these values can vary for different filesystem implementations.  Most
of these changes just use the existing default values with a few exceptions:
- Don't report CHOWN_RESTRICTED for ZFS since it doesn't do the exact
  permissions check this claims for chown().
- Use NANDFS_NAME_LEN for NAME_MAX for nandfs.
- Don't report a LINK_MAX of 0 on smbfs.  Now fail with EINVAL to
  indicate hard links aren't supported.

Requested by:	bde (though perhaps not this exact implementation)
Reviewed by:	kib (earlier version)
MFC after:	1 month
Sponsored by:	Chelsio Communications
2017-12-19 19:51:36 +00:00
Ed Maste
2dd51e16ca embed_mfs: support embedding mfs into loader
The script originally supported embedding an mfs into ELF files or any
other type of file, because it searched for magic strings to mark the
beginning and end of the embeddable section. It was later modified to
read the section offset and length via readelf, which made it work for
ELF only. Restore the ability to update arbitrary file types by using
the readelf technique for ELF, and the magic string technique for all
others (including PE/COFF files like loader.efi).

Submitted by:	Zakary Nafziger <worldofzak@gmail.com>
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D12746
2017-12-19 19:44:06 +00:00
John Baldwin
a0a073b16d Update NFS to handle larger link counts post ino64.
- Define a NFS_LINK_MAX as UINT32_MAX to match the wire protocol.
- Use NFS_LINK_MAX instead of LINK_MAX as the fallback value reported
  for a PATHCONF RPC by the NFS server.
- Use NFS_LINK_MAX instead of LINK_MAX as the default value reported
  by the NFS client pathconf() if not overridden by the NFS server.
- When reading the link count out of an RPC reply, read the full 32
  bits instead of the lower 16 bits.

Reviewed by:	rmacklem (earlier version)
Sponsored by:	Chelsio Communications
2017-12-19 19:18:48 +00:00
John Baldwin
4a62795260 Handle _PC_FILESIZEBITS and _PC_NO_TRUNC for smbfs' VOP_PATHCONF().
MFC after:	1 month
Sponsored by:	Chelsio Communications
2017-12-19 19:14:01 +00:00
John Baldwin
853b3a8ae8 Support _PC_FILESIZEBITS in msdosfs' VOP_PATHCONF().
MFC after:	1 month
Sponsored by:	Chelsio Communications
2017-12-19 19:10:00 +00:00
John Baldwin
746c92e04e Add a custom VOP_PATHCONF method for fuse.
This method handles _PC_FILESIZEBITS, _PC_SYMLINK_MAX, and _PC_NO_TRUNC.
For other values it defers to vop_stdpathconf().

MFC after:	1 month
Sponsored by:	Chelsio Communications
2017-12-19 19:09:06 +00:00
John Baldwin
697a86b6bf Adjust ZFS' link count handling for ino64.
- Define a ZFS_LINK_MAX as the ZFS version of LINK_MAX which is set to
  UINT64_MAX to match the on-disk format.
- Enable the currently #if 0'd code to check for link overflows and
  return EMLINK.
- Don't clamp the link count reported in stat() to LINK_MAX as that is
  still the 16-bit limit, but report the full link counts.  Also,
  avoid possibly overflowing the reported link count to 0 when adjusting
  the link count to account for ".snapshot".
- Update the LINK_MAX reported by pathconf() to report ZFS_LINK_MAX
  rather than LINK_MAX (but clamped to LONG_MAX for 32-bit systems).

Reviewed by:	avg (earlier version)
Sponsored by:	Chelsio Communications
2017-12-19 19:07:24 +00:00
John Baldwin
dd688800e1 Add a custom VOP_PATHCONF method for fdescfs.
The method handles NAME_MAX and LINK_MAX explicitly.  For all other
pathconf variables, the method passes the request down to the underlying
file descriptor.  This requires splitting a kern_fpathconf() syscallsubr
routine out of sys_fpathconf().  Also, to avoid lock order reversals with
vnode locks, the fdescfs vnode is unlocked around the call to
kern_fpathconf(), but with the usecount of the vnode bumped.

MFC after:	1 month
Sponsored by:	Chelsio Communications
2017-12-19 18:20:38 +00:00
Stephen Hurd
78fcf2de93 Add byte swapping in bnxt_cfg_async_cr() request
The firmware is always in little endian, use htole*() for all request fields
larger than one byte.

Submitted by:	Bhargava Chenna Marreddy <bhargava.marreddy@broadcom.com>
Sponsored by:	Broadcom Limited
2017-12-19 18:12:18 +00:00
Stephen Hurd
96fc97c81f Update Matthew Macy contact info
Email address has changed, uses consistent name (Matthew, not Matt)

Reported by:	Matthew Macy <mmacy@mattmacy.io>
Differential Revision:	https://reviews.freebsd.org/D13537
2017-12-19 17:59:00 +00:00
Mark Johnston
9abe2e7e98 Avoid using bioq_* in gmirror.
gmirror does not perform any sorting of I/O requests, so the bioq API
doesn't provide any advantages over plain TAILQs. The API also does not
provide operations needed by an upcoming change.

No functional change intended. The diff shrinks the geom_mirror.ko
text and the gmirror softc slightly.

Tested by:	pho (part of a larger patch)
MFC after:	1 week
Sponsored by:	Dell EMC Isilon
2017-12-19 17:13:04 +00:00
Alan Cox
22fd1b5dc6 Document the semantics of atomic_thread_fence operations.
Add atomic_load_<type> and atomic_store_<type>, and explain why they
exist.

Define the synchronizes-with relationship and its effects.

Reorder and revise some of the existing text.  For example, more
precisely describe when ordinary accesses are atomic.

Reviewed by:	jhb, kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D13522
2017-12-19 17:07:50 +00:00
Nathan Whitehorn
d6716aa2af The highest-order bit of the bootloader cookie is 1, with the result that
the 32-bit cookie can be sign-extended on its way out of the loader and
through Open Firmware. If sign-extended, the in-kernel check of its value
would fail on 64-bit systems, resulting in a mountroot prompt. Solve this
by telling the kernel to ignore the high-order bits.

PR:		kern/224437
Submitted by:	Gustavo Romero
2017-12-19 16:45:40 +00:00
Nathan Whitehorn
7cc0ad62e3 Make __startkernel line up with KERNBASE, so that the math to compute the
applied relocation offset in link_elf.c works as intended. We may want to
revisit how that works in future, for example by having elf_reloc_self()
actually store the numbers it is using rather than computing them later,
but this fixes symbol lookup after r326203.

Reported by:	andreast@
Pointy hat to:	me
2017-12-19 15:50:46 +00:00
Konstantin Belousov
e44f4f3547 mlx5en: Avoid SFENCe on x86
The IA32 memory model guarantees that all writes are seen in the program
order.  Also, any access to the uncacheable memory flushes the store
buffers.  As the consequence, SFENCE instruction is (almost) never needed,
in particular, it is not needed to ensure the correct order of updates as
seen by a PCIe device.

Use atomic_thread_fence_rel() instead of wb() to only emit compiler barriers
on x86 there.  Other architectures get the right barrier instruction as
well.

Reviewed by:	hselasky
Sponsored by:	Mellanox Technologies
MFC after:	1 week
2017-12-19 14:11:41 +00:00
Konstantin Belousov
200f8117ba Perform all accesses to uma_reclaim_needed using atomic(9) KPI.
Reviewed by:	alc, jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D13534
2017-12-19 10:06:55 +00:00
Konstantin Belousov
6f697994fd Use atomic_load(9) to read ppsinfo sequence numbers.
In this case volatile qualifiers enusre that a compiler does not
optimize the accesses out.

Reviewed by:	alc, jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D13534
2017-12-19 10:05:45 +00:00
Konstantin Belousov
30d4f9e888 Add atomic_load(9) and atomic_store(9) operations.
They provide relaxed-ordered atomic access semantic.  Due to the
FreeBSD memory model, the operations are syntaxical wrappers around
the volatile accesses.  The volatile qualifier is used to ensure that
the access not optimized out and in turn depends on the volatile
semantic as implemented by supported compilers.

The motivation for adding the operation is to help people coming from
other systems or knowing the C11/C++ standards where atomics have
special type and require use of the special access operations.  It is
still the case that FreeBSD requires plain load and stores of aligned
integer types to be atomic.

Suggested by:	jhb
Reviewed by:	alc, jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D13534
2017-12-19 09:59:20 +00:00
Warner Losh
5cf3cd108f When doing a dump, the scheduler is normally not running, so this
changed worked to capture dumps for me. However, the test for
SCHEDULER_STOPPED() isn't right. We can also call the dump routine
from ddb, in which case the scheduler is still running. This leads to
an assertion panic that we're sleeping when we shouldn't. Instead, use
the proper test for dumping or not. This brings us in line with other
places that do special things while we're doing polled I/O like this.

Noticed by: pho@
Differential Revision: https://reviews.freebsd.org/D13531
2017-12-19 04:13:22 +00:00
Warner Losh
fc1340fb40 No need to use relative paths like this here.
Sponsored by: Netflix
2017-12-19 04:06:07 +00:00
Warner Losh
ca481bffc2 Hoist btx include stuff to i386/Makefile.inc
Sponsored by: Netflix
2017-12-19 04:06:02 +00:00
Warner Losh
6bc860372d Interact is always called with NULL. Simplify code a little by
removing this argument, and expanding when rc is NULL. This
effectively completes the back out of custom scripts for tftp booted
loaders from r269153 that was started in r292344 with the new path
tricks that obsoleted it.

Submitted by: Netflix
2017-12-19 04:05:55 +00:00
Warner Losh
0ff3f28b2d Simplify things a little. The RETURN macro isn't required. It's only
used once, inside an #ifdef where it would be defined to be return.

Sponsored by: Netflix
2017-12-19 04:05:43 +00:00
Eitan Adler
9ff7bf7a93 arc lint: ignore /tests/ in chmod
shell scripts in scripts don't need
to be chmod +x to work. In fact most are not.
Of the tests I found from a simple search:
65 are chmod +x
84 are chmod -x

simply disable the check for test shell scripts.

Recommit requested by:	cem, rgrimes
2017-12-19 03:38:06 +00:00
Eitan Adler
8fbecf7b2e arclint: revert in prep for recommitting 2017-12-19 03:35:39 +00:00
Ed Maste
a5d5fd9ffd lld: Don't write preemptible symbol values to the .got.
It is not necessary and matches what bfd and gold do.

This was a regression from [LLVM] r315658.

Obtained from:	LLVM r321023 by Rafael Espíndola
2017-12-19 03:15:20 +00:00
Conrad Meyer
e054cac74a Implement ACPI CPU support when Processor object is not present
By the ACPI standard (ACPI 5 chapter 8.4 Declaring Processors) Processors
can be implemented in 2 distinct ways:

* Through a Processor object type (which provides P_BLK)
* Through a Device object type

Prior to this change, the FreeBSD driver only supported the former.  AMD
Epyc / Poweredge systems we are testing both implement the latter only.  Add
the missing support.

Because P_BLK is not defined in the device object case, C-states entering
must be completely controlled via _CST methods rather than P_LVL2/3.

John Baldwin points out that ACPI 6.0 formally deprecates the Processor
keyword, so eventually processors will only be enumerated as Device objects.

Submitted by:	attilio
Reviewed by:	jhb, markj, Anton Rang <rang AT acm.org>
Relnotes:	maybe
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D13457
2017-12-19 02:49:11 +00:00
Warner Losh
22cf6021fc Support more images (but still no geli)
Print a qemu line to a shell script to ease testing each image
Start to support multiple architectures (still very green)
Create /etc/rc that echos success and halts the system for better
automation (also include halt)
Create /etc/fstab on a per-boot type to test loader's passing root
to kernel.

This lets me run a test, connect to it with telnet and get either a
timeout, or a report of success.

Sponsored by: Netflix
2017-12-19 00:18:17 +00:00
John Baldwin
3a014c56c1 Catch up to r325719 which makes the kern.proc.pid sysctl "work" for zombies.
Some of the ptrace tests need to wait for a child process to become a
zombie before preceding.  The parent process polls the child process
via the kern.proc.pid sysctl to wait for it to become a zombie.
Previously the code polled until the sysctl failed with ESRCH.  Now it
will poll until either the sysctl fails with ESRCH (for compatiblity
with older kernels) or returns a kinfo_proc structure with the ki_stat
field set to SZOMB.

Reported by:	Jenkins
Tested by:	markj
Discussed with:	mjg
MFC after:	1 week
2017-12-18 23:35:14 +00:00
Warner Losh
989c7f0b7c Although we only have one quirk at the moment, guard against the day
we have more than one by checking the actual quirk bit before delaying
the reset.

Noticed by: rpokala@
2017-12-18 20:11:21 +00:00
Warner Losh
ce1ec9c178 When we're disabling the nvme device, some drives have a controller
bug that requires 'hands off' for a period of time (2.3s) before we
check the RDY bit. Sicne this is a very odd quirk for a very limited
selection of drives, do this as a quirk. This prevented a successful
reset of the card when the card wedged.

Also, make sure that we comply with the advice from section 3.1.5 of
the 1.3 spec says that transitioning CC.EN from 0 to 1 when CSTS.RDY
is 1 or transitioning CC.EN from 1 to 0 when CSTS.RDY is 0 "has
undefined results". Short circuit when EN == RDY == desired state.

Finally, fail the reset if the disable fails. This will lead to a
failed device, which is what we want. (note: nda device needs
work for coping with a failed device).

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D13389
2017-12-18 18:38:00 +00:00
Mark Johnston
6c7828a280 Avoid CPU migration in dtrace_gethrtime() on x86.
dtrace_gethrtime() may be called outside of probe context, and in
particular, from the DTRACEIOC_BUFSNAP handler.

Disable interrupts rather than using sched_pin() to help ensure that
we don't call any external functions when in probe context.

PR:		218452
MFC after:	1 week
2017-12-18 17:26:24 +00:00
Bruce Evans
d5d5600725 Also forgotten in the previous that removed the permanent double mapping
of low physical memory:

Update the comment about leaving the permanent mapping in place.  This
also improves the wording of the comment.  PTD 0 is still left alone
because it is fairly important that it was unmapped earlier, and the
comment now describes the unmapping of the other low PTDs that the code
actually does.

Reviewed by:	kib
2017-12-18 14:29:48 +00:00
Bruce Evans
2ba6fe0009 Remove the permanent double mapping of low physical memory and replace
it by a transient double mapping for the one instruction in ACPI wakeup
where it is needed (and for many surrounding instructions in ACPI resume).
Invalidate the TLB as soon as convenient after undoing the transient
mapping.  ACPI resume already has the strict ordering needed for this.

This fixes the non-trapping of null pointers and other garbage pointers
below NBPDR (except transiently).  NBPDR is quite large (4MB, or 2MB for
PAE).

This fixes spurious traps at the first instruction in VM86 bioscalls.
The traps are for transiently missing read permission in the first
VM86 page (physical page 0) which was just written to at KERNBASE in
the kernel.  The mechanism is unknown (it is not simply PG_G).

locore uses a similar but larger transient double mapping and needs
it for 2 instructions instead of 1.  Unmap the first PDE in it after
the 2 instructions to detect most garbage pointers while bootstrapping.
pmap_bootstrap() finishes the unmapping.

Remove the avoidance of the double mapping for a recently fixed special
case.  ACPI resume could use this avoidance (made non-special) to avoid
any problems with the transient double mapping, but no such problems
are known.

Update comments in locore.  Many were for old versions of FreeBSD which
tried to map low memory r/o except for special cases, or might have
allowed access to low memory via physical offsets.  Now all kernel
maps are r/w, and removal of of the double map disallows use of physical
offsets again.
2017-12-18 13:53:22 +00:00
Bruce Evans
4a5eb9ac99 Fix the undersupported option KERNLOAD, part 2: fix crashes in locore
when KERNLOAD is smaller than NBPDR (not the default) and PG_G is
enabled (the default if the CPU supports it).  This case has relatively
minor problems with coherency of the permanent double mapping, but the
fix in r167869 to improve coherency creates page tables with 3 different
errors so never worked.

The permanent double mapping is fundamentally broken and will be removed
soon.  It fundamentally breaks trapping for null pointers and requires
complications to avoid cache coherency bugs.  It is currently used for
only a single instruction in ACPI resume,

Many fixes VM86 and/or ACPI and/or the double map were attempted near
r1200000.  r167869 attempted to fix cache coherency bugs in an unusual
case, but the bugs were unreachable because older errors in page tables
caused a crash first.

This commit just makes r167869 work as intended.  Part 1 of these fixes
fixed the other errors, but also stopped mapping the PDE for KERNBASE
as a large page, so double mapping of this PDE only causes the same
problems as when KERNLOAD is the default.  Except for the problem of
trapping null pointers, r167869 could be used to fix these problems,
but it is inactive in usual cases.  The only known other problem is
that incoherent permissions for page 0 cause spurious traps in VM86
BIOS calls.

Reviewed by:	kib
2017-12-18 11:57:05 +00:00
Baptiste Daroussin
64874a795e newsyslog: Fix issues after r326616
When building the command to execute for compression, newsyslog was modifying
the generic arguments array instead of its own copy.
Meaning on the second file to compress with the same arguments, the command line
was not the one expected.
Fix it by creating one copy of the arguments per execution and modifying that
copy.

While here, print the command line executed in verbose mode.

Reported by:	many
2017-12-18 09:35:04 +00:00
Bruce Evans
3f21dc2985 Fix the undersupported option KERNLOAD, part 1: fix crashes in locore
when KERNLOAD is not a multiple of NBPDR (not the default) and PSE is
enabled (the default if the CPU supports it).  Addresses in PDEs must
be a multiple of NBPDR in the PSE case, but were not so in the crashing
case.

KERNLOAD defaults to NBPDR.  NBPDR is 4 MB for !PAE and 2 MB for PAE.
The default can be changed by editing i386/include/vmparam.h or using
makeoptions.  It can be changed to less than NBPDR to save real and
virtual memory at a small cost in time, or to more than NBPDR to waste
real and virtual memory.  It must be larger than 1 MB and a multiple of
PAGE_SIZE.  When it is less than NBPDR, it is necessarily not a multiple
of NBPDR.  This case has much larger bugs which will be fixed in part 2.

The fix is to only use PSE for physical addresses above <KERNLOAD
rounded _up_ to an NBPDR boundary>.  When the rounding is non-null,
this leaves part of the kernel not using large pages.  Rounding down
would avoid this pessimization, but would break setting of PAT bits
on i/o pages if it goes below 1MB.  Since rounding down always goes
below 1MB when KERNLOAD < NBPDR and the KERNLOAD > NBPDR case is not
useful, never round down.

Fix related style bugs (e.g., wrong literal values for NBPDR in comments).

Reviewed by:	kib
2017-12-18 09:32:56 +00:00
Warner Losh
76a8f5b0be libficl is only ever used in a loader (never a boot) program. Move it
to loader.mk.

Sponsored by: Netflix
2017-12-18 04:51:45 +00:00
Warner Losh
25c2f4cb95 Move loader help file definitions to being 100% inside of loader.mk.
HELP_FILES is a loader only thing, so move it to loader.mk. Only
generate the help file if HELP_FILES is defined. Adjust Makefiles to
new convention. Fix a few cases where ${.CURDIR}/ was missing
resulting in missing bits from the help files.

Sponsored by: Netflix
2017-12-18 04:51:34 +00:00
Ian Lepore
b5496277c7 Do not attempt to refill the TX fifo if there is no data left to transfer.
A comment in bcm_bsc_fill_tx_fifo() even lists sc_totlen > 0 as a
precondition for calling the routine.   I apparently forgot to make the
code do what my comment said.
2017-12-18 02:34:37 +00:00