controllers. bge(4) exported MAC statistics on controllers that
maintain the statistics in the NIC's internal memory. Newer
controllers require register access to fetch these values. These
counters provide useful information to diagnose driver issues.
parent driver. Use that information to configure flow-control.
One drawback is there is no way to disable flow-control as we still
don't have proper way to not advertise RX/TX pause capability to
link partner. But I don't think it would cause severe problems and
users can selectively disable flow-control in switch port.
has reached. This reduced number of dropped frames when
flow-control is enabled. Previously it dropped incoming frames once
RX MBUF low watermark has reached. The value used in MAC RX MBUF
low watermark is greater than or equal to 4 so receiving two more
RX frames should not be a problem.
Obtained from: OpenBSD
too many bge(4) controllers there and model name does not
necessarily match asic/chip revision. Relying on VPD string made
it hard to identify exact asic/chip revision so the first step to
debug bge(4) was getting exact asic/chip information with verbose
boot which may not be available on production server.
already updated after allocating mbuf so driver had to use the last
index instead of using next producer index. This should fix driver
hang which may happen under high network load.
Reported by: Igor Sysoev <is <> rambler-co dot ru>, Vlad Galu <dudu <> dudu dot ro>
Tested by: Igor Sysoev <is <> rambler-co dot ru>, Vlad Galu <dudu <> dudu dot ro>
MFC after: 10 days
or not by comparing reported TX consumer index with saved index. So
remove unnecessary check done after freeing transmitted mbufs.
While I'm here nuke unnecessary variable initializations.
tag. All controllers that are not BCM5755 or higher have 4GB
boundary DMA bug. Previously bge(4) used 32bit DMA address to
workaround the bug(r199670). However this caused the use of bounce
buffers such that it resulted in poor performance for systems which
have more than 4GB memory. Because bus_dma(9) honors boundary
restriction requirement of DMA tag for dynamic buffers, having a
separate TX/RX mbuf DMA tag will greatly reduce the possibility of
using bounce buffers. For DMA buffers allocated with
bus_dmamem_alloc(9), now bge(4) explicitly checks whether the
requested memory region crossed the boundary or not.
With this change, only the DMA buffer that crossed the boundary
will use 32bit DMA address. Other DMA buffers are not affected as
separate DMA tag is created for each DMA buffer.
Even if 32bit DMA address space is used for a buffer, the chance to
use bounce buffer is still very low as the size of buffer is small.
This change should eliminate most usage of bounce buffers on
systems that have more than 4GB memory.
More correct fix would be teaching bus_dma(9) to honor boundary
restriction for buffers created with bus_dmamem_alloc(9) but it
seems that is not easy.
While I'm here cleanup bge_dma_map_addr() and remove unnecessary
member variables in bge_dmamap_arg structure.
Tested by: marcel
datagrams with checksum value 0 when TX UDP checksum offloading is
enabled. Generating UDP checksum value 0 is RFC 768 violation.
Even though the probability of generating such UDP datagrams is
low, I don't want to see FreeBSD boxes to inject such datagrams
into network so disable UDP checksum offloading by default. Users
still override this behavior by setting a sysctl variable or loader
tunable, dev.bge.%d.forced_udpcsum.
I have no idea why this issue was not reported so far given that
bge(4) is one of the most commonly used controller on high-end
server class systems. Thanks to andre@ who passed the PR to me.
PR: kern/104826
r165114 added that code and that change ignored the same logic
committed in r135772. In addition, data FIFO protection should be
selectively enabled instead of applying to all PCIe devices.
While I'm here add BCM5785 to devices that do not require this
fix.
configuration to get IPv4 TSO work on BCM57780. While I'm here
apply the same fix to BCM5785 which shares similar hardware feature
of BCM57780. This change makes TSO work on BCM57780.
Tested by: Tong Liu <nemoliu <> gmail dot com>
buffers it should also reinitialize RX descriptors otherwise some
stale data could be passed to controller. This could end up with
mbuf double free or unexpected NULL pointer dereference in upper
stack. To fix the issue, save loaded buffer's length and
reinitialize RX descriptors with the saved value whenever bge(4)
reuses the loaded RX buffers.
While I'm here, increase the number of RX buffers to 512 from 256.
This simplifies RX buffer handling as well as giving more RX
buffers. Controller supports just fixed number of RX buffers
(i.e. 512) and bge(4) used to rely on hope that our CPU is fast
enough to keep up with the controller. With this change, bge(4)
will use 1MB for RX buffers but I don't think it would cause
problems in these days.
Reported by: marcel
Tested by: marcel
index of status block is read first before acknowledging the
interrupts. Otherwise bge(4) may get stale status block as
acknowledging an interrupt may yield another status block update.
Reviewed by: marius
Also disable relaxed ordering as recommended by data sheet for
PCI-X devices. For PCI-X BCM5704, set maximum outstanding split
transactions to 0 as indicated by data sheet.
For BCM5703 in PCI-X mode, DMA read watermark should be less than
or equal to maximum read byte count configuration. Enforce this
limitation in DMA read watermark configuration.
the issue. I still have no idea why TSO does not work on this
controller. davidch@ also confirmed there is no known TSO related
issues for this controller.
not support TSO over VLAN if VLAN hardware tagging is disabled so
there is no need to check VLAN here.
While I'm here make sure to pullup IP/TCP headers in the first
buffer.
to make TSO work on VLAN. So if VLAN hardware tagging is disabled
explicitly clear TSO on VLAN. While I'm here remove duplicated
VLAN_CAPABILITIES call.
The softc obtained in device probe wouldn't be the same one used in
device attach. Drivers should not assume any values stored in softc
structure in probe routine will be available for its attach routine.
no effect. Make sure to clear error bits by writing 1. [1]
While I'm here use predefined value instead of hardcodig magic
vlaue.
Submitted by: msaitoh at NetBSD [1]
implementation of heartbeat interval was 2 but there was typo which
caused the heartbeat is sent approximately every 5 seconds. This
caused unintended controller reset by firmware because firmware
thought OS was crashed.
Submitted by: Floris Bos < info <> je-eigen-domein dot nl >
Tested by: Andrzej Tobola < ato <> iem dot pw dot edu dot pl >
chains. This part of code is to enhance performance so failing the
collapsing should not free TX frames. Otherwise bge(4) will
unnecessarily drop frames which in turn can freeze the network
connection.
Reported by: Igor Sysoev (is <> rambler-co dot ru)
Tested by: Igor Sysoev (is <> rambler-co dot ru)
over GMII, make sure to enable GMII. With this change brgphy(4) is
used to handle the dual mode PHY. Since we still don't have a sane
way to pass PHY specific information to mii(4) layer special
handling is needed in brgphy(4) to determine which mode of PHY was
configured in parent interface.
This change make BCM5715S work.
Tested by: olli
Obtained from: OpenBSD
MFC after: 1 week
o Don't enable BGE_FLAG_BER_BUG on both 5722 and 5756, and based
on their PCI IDs rather than their chip IDs.
Reported by: several PC-BSD users via kmoore
Reviewed by: yongari, imp, jhb, davidch
Sponsored by: iXsystems, Inc.
MFC after: 2 weeks
same ASIC ID of BCM5758 such that r198318 incorecctly enabled TSO
on BCM5754.BCM5754M controllers. BCM5754/BCM5754M needs a special
firmware to enable TSO and bge(4) does not support firmware based
TSO.
Reported by: ed
Tested by: ed
hw.bge.forced_collapse. hw.bge.forced_collapse affects all bge(4)
controllers on system which may not desirable behavior of the
sysctl node. Also allow the sysctl node could be modified at any
time.
Reviewed by: bde (initial version)
feature. These registers are reserved on controllers that have no
support for jumbo frame.
Only BCM5700 has mini ring so do not poke mini ring related
registers if controller is not BCM5700.
Reviewed by: marius
handler in brgphy(4) does not exist and brgphy(4) just resets the
PHY and returns EINVAL as it has no isolation handler. I also agree
on Marius's opinion that stop handler of every NIC driver seems to
be the wrong place for implementing PHY isolate/power down.
If we need PHY isolate/power down it should be implemented in
brgphy(4) and users should administratively down the PHY.
Reviewed by: marius
single outstanding DMA read operation. Most controllers targeted to
client with PCIe bus interface(e.g. BCM5761) may have this
limitation. All controllers for servers does not have this
limitation.
Collapsing mbuf chains to reduce number of memory reads before
transmitting was most effective way to workaround this. I got about
940Mbps from 850Mbps with mbuf collapsing on BCM5761. However it
takes a lot of CPU cycles to collapse mbuf chains so add tunable to
control the number of allowed TX buffers before collapsing. The
default value is 0 which effectively disables the forced collapsing.
For most cases 2 would yield best performance(about 930Mbps)
without much sacrificing CPU cycles.
Note the collapsing is only activated when the controller is on
PCIe bus and the frame does not need TSO operation. TSO does not
seem to suffer from the hardware limitation because the payload
size is much bigger than normal IP datagram.
Thanks to davidch@ who told me the limitation of client controllers
and actually gave possible workarounds to mitigate the limitation.
Reviewed by: davidch, marius
Tx/Rx/Rx return ring such that large part of status block was not
used at all. All bge(4) controllers except BCM5700 AX/BX has a
feature to control the size of status block. So use minimum status
block size allowed in controller. This reduces number of DMAed
status block size to 32 bytes from 80 bytes.
seem to require a special firmware to use TSO. But the firmware is
not available to FreeBSD and Linux claims that the TSO performed by
the firmware is slower than hardware based TSO. Moreover the
firmware based TSO has one known bug which can't handle TSO if
ethernet header + IP/TCP header is greater than 80 bytes. The
workaround for the TSO bug exist but it seems it's too expensive
than not using TSO at all. Some hardwares also have the TSO bug so
limit the TSO to the controllers that are not affected TSO issues
(e.g. 5755 or higher).
While I'm here set VLAN tag bit to all descriptors that belengs to
a frame instead of the first descriptor of a frame. The datasheet
is not clear how to handle VLAN tag bit but it worked either way in
my testing. This makes it simplify TSO configuration a little bit.
Big thanks to davidch@ who sent me detailed TSO information.
Without this I was not able to implement it.
Tested by: current
have a DMA bug when buffer address crosses a multiple of the 4GB
boundary(e.g. 4GB, 8GB, 12GB etc). Limit DMA address to be within
4GB address for these controllers. The second DMA bug limits DMA
address to be within 40bit address space. This bug applies to
BCM5714 and BCM5715 and 5708(bce(4) controller). This is not
actually a MAC controller bug but an issue with the embedded PCIe
to PCI-X bridge in the device. So for BCM5714/BCM5715 controllers
also limit the DMA address to be within 40bit address space.
Special thanks to davidch@ who gave me detailed errata information.
I think this change will fix long standing bge(4) instability
issues on systems with more than 4GB memory.
Reviewed by: davidch
PCI flush to get correct status block update. Add an optimized
interrupt handler that is activated for MSI case. Actual interrupt
handling is done by taskqueue such that the handler does not
require driver lock for Rx path. The MSI capable bge(4) controllers
automatically disables further interrupt once it enters interrupt
state so we don't need PIO access to disable interrupt in interrupt
handler.
update and then clear status block. Previously it used to access
these index without synchronization which may cause problems when
bounce buffers are used. Also add missing bus_dmamap_sync(9) in
polling handler. Since we now update status block in driver, adjust
bus_dmamap_sync(9) for status block.
checking IFF_DRV_RUNNING and IFF_DRV_OACTIVE flags. Also if we
have less than 16 free send BDs set IFF_DRV_OACTIVE and try it
later. Previously bge(4) used to reserve 16 free send BDs after
loading dma maps but hardware just need one reserved send BD. If
prouder index has the same value of consumer index it means the Tx
queue is empty.
While I'm here check IFQ_DRV_IS_EMPTY first to save one lock
operation.
directly access them at fixed address. While I'm here don't touch
other bits of PCIe device control register except max payload size.
Reviewed by: marius
Revision 1.158 says only lower ten bits of
BGE_RXLP_LOCSTAT_IFIN_DROPS register is valid. For BCM5761 case it
seems the controller maintains 16bits value for the register.
However 16bits are still too small to count all dropped packets
happened in a second. To get a correct counter we have to read the
register in bge_rxeof() which would be too expensive.
Pointed out by: bde
MAC in bge_tick. Previously it used to show more number of input
errors. I noticed actual input errors were less than 8% even for
64 bytes UDP frames generated by netperf.
Since we always access BGE_RXLP_LOCSTAT_IFIN_DROPS register in
bge_tick, remove useless code protected by #ifdef notyet.
initializes it to ETHER_HDR_LEN so we have to override it after
calling ether_ifattch().
While I'm here remove setting if_mtu value, it's initialized in
ether_ifattach().
Introduce two spare dma maps for standard buffer and jumbo buffer
respectively. If loading a dma map failed reuse previously loaded
dma map. This should fix unloaded dma map is used in case of dma
map load failure. Also don't blindly unload dma map and defer
dma map sync and unloading operation until we know dma map for new
buffer is successfully loaded. This change saves unnecessary dma
load/unload operation. Previously bge(4) tried to reuse mbuf
with unloaded dma map which is really bad thing in bus_dma(9)
perspective.
While I'm here update if_iqdrops if we can't allocate Rx buffers.
standard buffer size. If controller is not capable of handling
jumbo frame, interface MTU couldn't be larger than standard MTU
which in turn the received should be fit in standard buffer. This
fixes bus_dmamap_sync call for jumbo ring is called even if
interface is configured to use standard MTU.
Also if total frame size could be fit into standard buffer don't
use jumbo buffers.
for buffer allocation. If driver know we are out of Rx buffers let
controller stop. This should fix panic when interface is run even
if it had no configured Rx buffers.
and Rx DMA tag separately. Previously it used a common mbuf DMA tag
for both Tx and Rx path but Rx buffer(standard ring case) should
have a single DMA segment and maximum buffer size of the segment
should be less than or equal to MCLBYTES. This change also make it
possible to add TSO with minor changes.
bge_newbuf_std still has a bug for handling dma map load failure
under high network load. Just reusing mbuf is not enough as driver
already unloaded the dma map of the mbuf. Graceful recovery needs
more work.
Ideally we can just update dma address part of a Rx descriptor
because the controller never overwrite the Rx descriptor. This
requires some Rx initialization code changes and it would be done
later after fixing other incorrect bus_dma(9) usages.
instead of POSTREAD: the hardware do not touch this memory (CPU
updates it). It is already synchronized as PREWRITE after the
processing is done.
- Synchronize RX return ring memory in rx_eof. This is needed
as the deviced updates this memory when receives packets.
- Decouple the synchronization of BGE status block in the interrupt
service routine: perfrom PREREAD synchronization only all accesses
to this block are finished. This seems to be more natural.
Reviewed by: yongari, marius
MFC after: 2 weeks
to the lock we hold, disable interrupts, and announce to the firmware
that we are shutting down. Especially do this before disabling blocks.
This makes some types of machines with asf enabled no longer hang upon
boot, when we start configuring the interface.
PR: i386/96382, kern/100410, kern/122252, kern/116328
Reported by: erwin
Hardware provided by: TDC A/S
Reviewed by: stas
Tested by: stas
BGE_PCI_PRODID_ASICREV register to store the chip identifier and its revision.
- Add new grouping macro for 7575+ chips (BGE_IS_5755_PLUS).
- Add IDs for Fujitsu-branded Broadcom adapters.
PR: kern/127587
Tested by: Thomas Quinot <thomas@quinot.org> (BCM7561 A0)
MFC after: 2 weeks
Obtained from: OpenBSD
loop iteration as it can be updated by the card while we
process the RX ring forcing us to process RX descriptors
for which DMA synchronisation operation has not been
performed. This fixes the bug when bge(4) drops packets
under high load.
Discussed with: yongari, marius
Approved by: re (kib)
MFC after: 1 week
IF_ADDR_UNLOCK() across network device drivers when accessing the
per-interface multicast address list, if_multiaddrs. This will
allow us to change the locking strategy without affecting our driver
programming interface or binary interface.
For two wireless drivers, remove unnecessary locking, since they
don't actually access the multicast address list.
Approved by: re (kib)
MFC after: 6 weeks
CPU for too long period than necessary. Additively, interfaces are kept
polled (in the tick) even if no more packets are available.
In order to avoid such situations a new generic mechanism can be
implemented in proactive way, keeping track of the time spent on any
packet and fragmenting the time for any tick, stopping the processing
as soon as possible.
In order to implement such mechanism, the polling handler needs to
change, returning the number of packets processed.
While the intended logic is not part of this patch, the polling KPI is
broken by this commit, adding an int return value and the new flag
IFCAP_POLLING_NOCOUNT (which will signal that the return value is
meaningless for the installed handler and checking should be skipped).
Bump __FreeBSD_version in order to signal such situation.
Reviewed by: emaste
Sponsored by: Sandvine Incorporated
drops and re-grabs the softc mutex in the middle, resulting in kernel
trap 12. This may happen when a lot of traffic is being hammered on
one bge(4) interface while the system is shutting down.
Reported by: Alexander Sack <pisymbol gmail com>
PR: kern/134548
MFC After: 2 weeks
quirk requiring it to be enabled even when using MSI. This makes
the latter work again after r189285.
- Remove a comment which no longer applies since r190194.
- If boot verbose, print asicrev, chiprev and bus type on attach.
- For PCI Express devices:
1) Adjust max read request size to 4Kbytes
2) Turn on FIFO_LONG_BURST in RDMA during bge_blockinit()
Though 1) does not seem to have much to do with the poor TX performance
observed on PCI Express bge(4), 2) does fix the problem. [1]
- Nuke the RX CPU self-diag, which prevents working cards from working
(Linux tg3 does not have this diag neither does OpenBSD's bge(4)).
The increasing of the firmware handshaking timeout to 20000 retries
done as part of the original commit isn't merged as way already have a
way higher BGE_TIMEOUT of 100000.
PR: 119361 [1]
Obtained from: tg3 via DragonflyBSD [1], DragonflyBSD
causes data corruption in combination with certain bridges.
Information about this problem was kindly provided by davidch. [1]
- As BGE_FLAG_PCIX is meant to indicate that the controller is in
PCI-X mode, revert to the pre __FreeBSD_version 602101 method of
reading the bus mode register rather than checking the mere
existence of a PCI-X capability, which is also there when the
NIC f.e. is put into a 32-bit slot causing it not to be in PCI-X
mode. Setting BGE_FLAG_PCIX inappropriately could cause the NIC
to be tuned incorrectly.
PR: 128833 [1]
Reviewed by: jhb
MFC after: 3 days
for the BCM5714 revision A0 when in a multi-port configuration
and unconditionally for the remainder of the class of BCM575X
and beyond chips.
This was prodded by mav and is based on a suggestion and a
patch submitted by jhb.
Reviewed by: jhb
MFC after: 2 months
containing an Ethernet address fitted as this is yet another thing
that fails in that case in order to avoid the one second delay
until pci_read_vpd_reg() times out.
- Const'ify the bge_devs array.
- Rename BGE_FLAG_EEPROM to BGE_FLAG_EADDR to underline it's absence means
"there's no chip containing an Ethernet address fitted to the BGE chip
so we have to get it from the firmware instead" rather than "there's no
EEPROM, but maybe NVRAM or something else".
- Don't treat BCM5906[M] generally like chips w/o BGE_FLAG_EADDR set, just
in the two cases really necessary. This gets us line with the original
patch for DragonFlyBSD.
- For sparc64 restore the intended behavior of obtaining the Ethernet
address from the firmware in case BGE_FLAG_EADDR is not set, even for
BCM5906[M].
- Fix some style(9) bugs introduced with rev. 1.208 of if_bge.c
Approved by: jhb
Additional testing by: Thomas Nystroem (BCM5906)
all cards/modes.
In addition to the intr forcing added with rev. 1.205 adopt the other
places to use the same logic.
We need to exclude a few chips/revisions (5700, 5788) from using the
enhanced version and fall back to the old way as that is the only
method they support.
Tested by: phk
Suggested by: davidch, Broadcom (thanks a lot for the help!)
MFC after: 16 days
10/100 operation and place the mailbox registers at a different offset.
They also do not have an EEPROM, so the MAC address must be read from
NVRAM instead.
MFC after: 1 month
PR: kern/118975
Submitted by: benjsc, Thomas Nyström thn at saeab dot se
Submitted by: sephe (original patch for DragonflyBSD)
when creating the parent bus DMA tag. While at it correct the style
and a nearby comment.
- Take advantage of m_collapse(9) for performance reasons.
MFC after: 2 weeks
Because of this we were not getting further interrupts for link state
changes, thus never went into iface UP state and thus could not transmit.
The only way out of this was an incoming packet generating an rx interrupt
and making us call into bge_link_upd.
Up to rev. 1.101, in bge_start_locked, we only returned instantly
if there was 'no link AND nothing queued for tx'. So with a packet queued
for tx, we hit the register scrubbing at the end of bge_start_locked
and were out fine. We simply lost a packet or two but got the interrupts
need to get into UP state.
With rev. 1.102 this was turned into 'if there is no link OR there is
nothing to send' (correct behaviour) and as long as there is no link
we never hit the register scrubbing and consequently never got the link UP.
What we do now is force an interrupt at the end of bge_ifmedia_upd_locked
so we will call bge_link_upd, clear the link state attention and get
further interrupts.
This helps to get the iface UP on an idle network or at least to get
it UP faster not depending on an rx intr anymore.
In case you could not get a DHCP lease or it took very long,
it was because of this.
It is unknown which chips are affected by this. ASIC rev. 0x2003 was the
most popular trouble candidate.
At least the fiber cards should have been working fine.
Which register to scrub is currently under discussion. The comitted
solution was tested and found to work for a lot of setups. It might
not help with MSI.
The reason why we end up in such a situation is entirely unknown.
PR: kern/111804
Tested by: phk, scottl at Y!
MFC after: 14 days
The register layout is little different from memory-mapped stats
in the previous generation chips. In fact, it is bad because
registers in this range are cleared after reading them.
Reviewed by: scottl
MFC after: 3 days
support machines having multiple independently numbered PCI domains
and don't support reenumeration without ambiguity amongst the
devices as seen by the OS and represented by PCI location strings.
This includes introducing a function pci_find_dbsf(9) which works
like pci_find_bsf(9) but additionally takes a domain number argument
and limiting pci_find_bsf(9) to only search devices in domain 0 (the
only domain in single-domain systems). Bge(4) and ofw_pcibus(4) are
changed to use pci_find_dbsf(9) instead of pci_find_bsf(9) in order
to no longer report false positives when searching for siblings and
dupe devices in the same domain respectively.
Along with this change the sole host-PCI bridge driver converted to
actually make use of PCI domain support is uninorth(4), the others
continue to use domain 0 only for now and need to be converted as
appropriate later on.
Note that this means that the format of the location strings as used
by pciconf(8) has been changed and that consumers of <sys/pciio.h>
potentially need to be recompiled.
Suggested by: jhb
Reviewed by: grehan, jhb, marcel
Approved by: re (kensmith), jhb (PCI maintainer hat)
sysctl_handle_int is not sizeof the int type you want to export.
The type must always be an int or an unsigned int.
Remove the instances where a sizeof(variable) is passed to stop
people accidently cut and pasting these examples.
In a few places this was sysctl_handle_int was being used on 64 bit
types, which would truncate the value to be exported. In these
cases use sysctl_handle_quad to export them and change the format
to Q so that sysctl(1) can still print them.
Blade 2500, Fire V210 and probably some other sparc64 machines.
These chips are typically not fitted with an EEPROM which means
that we have to obtain the MAC address via OFW and that some chip
tests will just always fail.
These changes are based on the respective code found in OpenBSD
with some additional info obtained from OpenSolaris and some style
suggestions by jkim@. They also have the desired side-effect of
respecting the 'local-mac-address?' system configuration variable
for the affected BGEs.
- In bge_attach() factor out calling bge_release_resources() before
going to the fail label into the fail label as well as replace a
magic 6 with ETHER_ADDR_LEN.
Reviewed by: yongari (before style changes), jkim
- Remove some excessive parentheses around shift operators.
- Use macro instead of magic number where it is applicable.
- Change lower-case hexdecimals to upper cases to match wpaul's style.
- Revert some unnecessary line wraps and changes from the previous commit.
Pointed out by: bde
- Move some PHY bug detections from brgphy.c to if_bge.c.
- Do not penalize working PHYs.
- Re-arrange bge_flags roughly by their categories.
- Fix minor style(9) nits.
PR: kern/107257
Obtained from: OpenBSD
Tested by: Mike Hibler <mike at flux dot utah dot edu>
bge_intr(). Some of them are used in bge_poll(). Simplify by only
initializing these for polling mode and not toggling them when switching
modes. This also fixes missing synchronization with the coalescing
engine in the toggling.
been handled instead of when at least one descriptor was just handled.
For bge, it is normal to get a txeof when only a small fraction of the
queued tx descriptors have been handled, so the bug broke the watchdog
in a usual case.
- moved the synchronizing bus read to after the bus write for the first
interrupt ack so that it actually synchronizes everything necessary.
We were acking not only the status update that triggered the interrupt
together with any status updates that occurred before we got around
to the bus write for the ack, but also any status updates that occur
after we do the bus write but before the write reaches the device.
The corresponding race for the second interrupt ack resulted in
sometimes returning from the interrupt handler with acked but
unserviced interrupt events. Such events then remain unserviced
until further events cause another interrupt or the watchdog times
out.
The race was often lost on my 5705, apparently since my 5705 has broken
event coalescing which causes a status update for almost every packet,
so another status update is quite likely to occur while the interrupt
handler is running. Watchdog timeouts weren't very noticeable,
apparently because bge_txeof() has one of the usual bugs resetting the
watchdog.
- don't disable device interrupts while bge_intr() is running. Doing this
just had the side effects of:
- entering a device mode in which different coalescing parameters apply.
Different coalescing parameters can be used to either inhibit or
enhance the chance of getting another status update while in the
interrupt handler. This feature is useless with the current
organization of the interrupt handler but might be useful with a
taskqueue handler.
- giving a race for ack+reenable/return. This cannot be handled
by simply rearranging the order of bus accesses like the race for
ack+keepenable/entry. It is necessary to sync the ack and then
check for new events.
- taking longer, especially with the extra code to avoid the race on
ack+reenable/return.
Reviewed by: ru, gleb, scottl
- Do not repeatedly read vendor/device IDs while probing.
- Remove redundant bzero(3) for softc. device_get_softc(9) does it for free[1].
Reviewed by: glebius
Suggested by: glebius[1]
