possible to end up in the interrupt handler again while processing the
previous RX interrupt in ifp->if_input() because the MD interrupt code
disables the delivery of the respective interrupt until all associated
handlers were called (in the INTR_FILTER case the MI code supposedly
does the same). Toggling the NIC interrupt enable bit in these handlers
still is necessary though as some chips (f.e. the VMware emulated one)
require this to be done in order to keep issuing interrupts.
MFC after: 1 month
still should return BUS_PROBE_LOW_PRIORITY instead of BUS_PROBE_DEFAULT
in order to give pcn(4) a chance to attach in case it probes after le(4).
- Rearrange the code related to RX interrupt handling so that ownership of
RX descriptors is immediately returned to the NIC after we have copied
the data of the hardware, allowing the NIC to already reuse the descriptor
while we are processing the data in ifp->if_input(). This results in a
small but measurable increase in RX throughput.
As a side-effect, this moves the workaround for the LANCE revision C bug
to am7900.c (still off by default as I doubt we will actually encounter
such an old chip in a machine running FreeBSD) and the workaround for the
bug in the VMware PCnet-PCI emulation to am79000.c, which is now also
only compiled on i386 (resulting in a small increase in RX throughput on
the other platforms).
- Change the RX interrupt handlers so that the descriptor error bits are
only check once in case there was no error instead of twice (inspired
by the NetBSD pcn(4), which additionally predicts the error branch as
false).
- Fix the debugging output of the RX and TX interrupt handlers; while
looping through the descriptors print info about the currently processed
one instead of always the previously last used one; remove pointless
printing of info about the RX descriptor bits after their values were
reset.
- Create the DMA tags used to allocate the memory for the init block,
descriptors and packet buffers with the alignment the respective NIC
actually requires rather than using PAGE_SIZE unconditionally. This might
as well fix the alignment of the memory as it seems we do not inherit
the alignment constraint from the parent DMA tag.
- For the PCI variants double the number of RX descriptors and buffers
from 8 to 16 as this minimizes the number of RX overflows im seeing with
one NIC-mainboard combination. Nevertheless move reporting of overflows
under debugging as they seem unavoidable with some crappy hardware.
- Set the software style of the PCI variants to ILACC rather than PCnet-PCI
as the former is was am79000.c actually implements. Should not make a
difference for this driver though.
- Fix the driver name part in the MODULE_DEPEND of the PCI front-end for
ether.
- Use different device descriptions for PCnet-Home and PCnet-PCI.
- Fix some 0/NULL confusion in lance_get().
- Use bus_addr_t for sc_addr and bus_size_t for sc_memsize as these are
more appropriate than u_long for these.
- Remove the unused LE_DRIVER_NAME macro.
- Add a comment describing why we are taking the LE_HTOLE* etc approach
instead of using byteorder(9) functions directly.
- Improve some comments and fix some wording.
MFC after: 2 weeks
processing the interrupt events. If we clear them afterwards we
can completely miss some events as the NIC can change the source
flags while we're in the handler. In order to not get another
interrupt while we're in ifp->if_input() with the driver lock
dropped we now turn off NIC interrupts while in the interrupt
handler. Previously this was meant to be achieved by clearing the
interrupt source flags after processing the interrupt events but
didn't really work as clearing these flags doesn't actually
acknowledge and re-enable the events.
This fixes the device timeouts seen with the VMware LANCE.
- Relax the watchdog timer somewhat; don't enable it until the last
packet is enqueued and if there is a TX interrupt but there are
still outstanding ones reload the timer.
Reported and tested by: Morten Rodal <morten@rodal.no>
MFC after: 3 days
from NetBSD. This driver actually can replace lnc(4). Advantages over
lnc(4) are:
- Cleaner and more flexible regarding MD needs.
- Endian-clean and MPSAFE.
- Supports ALTQ, VLAN_MTU, ifmedia.
- Uses 32bit DMA for the PCI variants.
This commit includes front-ends for the dma(4) pseudo-bus found on SBus-
based sparc64 machines (thus supports the on-board LANCE in Sun Ultra 1)
and PCI. In order to actually replace lnc(4), the front-ends for ISA and
the PC98 CBUS would have to be added but for which I don't have hardware
to test.
Reviewed and some improvements by: yongari
Tested on: i386, sparc64
