TX stalls in this driver, I've also had some
time to evaluate the effectiveness of different
watchdog strategies.
This is the latest attempt, which consolidates
all of the watchdog logic in one place and
consistently detects TX stalls and resets within
a couple of seconds.
(as used in AM335x SoC for BeagleBone).
Among other things:
* Watchdog reset doesn't hang the driver.
* Disconnecting cable doesn't hang the driver.
* ifconfig up/down doesn't hang the driver
* Out-of-memory no longer panics the driver.
Known issues:
* Doesn't have good support for fragmented packets
(calls m_defrag() on TX, assumes RX packets are never fragmented)
* Promisc and allmulti still unimplimented
* addmulti and delmulti still unimplemented
* TX queue still stalls (but watchdog now consistently recovers in ~5s)
* No sysctl monitoring
* Only supports port0
* No switch configuration support
* Not tested on anything but BeagleBone
Committed from: BeagleBone
- Add pl310.disable tunable to disable L2 cache altogether. In
order to make sure that it's 100% disabled we use cache event
counters for cache line eviction and read allocate events
and panic if any of these counters increased. This is purely
for debugging purpose
- Direct access DEBUG_CTRL and CTRL might be unavailable in
unsecure mode, so use platform-specific functions for
these registers
- Replace #if 1 with proper erratum numbers
- Add erratum 753970 workaround
- Remove wait function for atomic operations
- Protect cache operations with spin mutex in order to prevent race condition
- Disable instruction cache prefetch and make sure data cache
prefetch is enabled in OMAP4-specific intialization
Interrupts must be disabled while handling a partial cache line flush,
as otherwise the interrupt handling code may modify data in the non-DMA
part of the cache line while we have it stashed away in the temporary
stack buffer, then we end up restoring a stale value.
PR: 160431
Submitted by: Ian Lepore
Basically it's replica of VersatilePB code which is replica of XBox FB
code. All of them are linear framebuffers and should have common bits
moved to reusable framework.
- Disable interrupt when updating compare value in order to
make this operation atomical
- Increase minimum period for event timer. Systimer on BCM2835
is compare timer, so if minimum period is too small it might
be less then fraction of time between "read current value" and
"set compare timer" operations. It means that when timer is armed
actual counter value is more then compare value and it will take
whole cycle (~32sec for 1MHz timer) to fire interrupt.
Submitted by: Daisuke Aoyama <aoyama at peach.ne.jp>
allocate a map or mapping resources. That seems to imply that any memory
allocations it does must use M_NOWAIT and check for NULL.
Submitted by: Ian Lepore <freebsd@damnhippie.dyndns.org>
- Use the new architecture-agnostic buffer pool manager that uses uma(9)
to manage a set of power-of-2 sized buffers for bus_dmamem_alloc().
- Create pools of buffers backed by both regular and uncacheable memory,
and use them to handle regular versus BUS_DMA_COHERENT allocations.
- Use uma(9) to manage a pool of bus_dmamap structs instead of local code
to manage a static list of 500 items (it took 3300 maps to get to
multi-user mode, so the static pool wasn't much of an optimization).
- Small BUS_DMA_COHERENT allocations no longer waste an entire page per
allocation, or set pages to uncached when they contain data other than
DMA buffers. There's no longer a need for drivers to work around the
inefficiency by allocing large buffers then sub-dividing them.
- Because we know the alignment and padding of buffers allocated by
bus_dmamem_alloc() (whether coherent or regular memory, and whether
obtained from the pool allocator or directly from the kernel) we
can avoid doing partial cacheline flushes on them.
- Add a fast-out to _bus_dma_could_bounce() (and some comments about
what the routine really does because the old misplaced comment was wrong).
- Everywhere the dma tag alignment is used, the interpretation is that
an alignment of 1 means no special alignment. If the tag is created
with an alignment argument of zero, store it in the tag as one, and
remove all the code scattered around that changed 0->1 at point of use.
- Remove stack-allocated arrays of segments, use a local array of two
segments within the tag struct, or dynamically allocate an array at first
use if nsegments > 2. On an arm system I tested, only 5 of 97 tags used
more than two segments. On my x86 desktop it was only 7 of 111 tags.
Submitted by: Ian Lepore <freebsd@damnhippie.dyndns.org>
much all the union of all the kernel configuration files, including all
the CPU types, Marvell SOC types and at91 board types. Any device not
supported (read: does not compile) has been removed, which is a fairly
small set actually. As such, LINT gives us very good coverage without
having to build a zillion kernels.
expand to uncompilable code when the kernel configuration contains
"options DEBUG", such as it is for LINT. The toolchain is often a
better approach to figure this out, as it doesn't require one to
boot the kernel.
interfere with structure fields of the same name in drivers, like
the intr_disable function pointer in struct cphy_ops in cxgb(4).
Instead define intr_disable and intr_restore as inline functions.
With intr_disable() an inline function, the I32_bit and F32_bit
macros now need to be visible in MI code and given the rather
poor names, this is not at all good. Define ARM_CPSR_F32 and
ARM_CPSR_I32 and use that instead of F32_bit and I32_bit (resp)
for now.
