linux-toradex.git/drivers/firewire/ohci.c, branch v3.14.2

firewire: ohci: fix probe failure with Agere/LSI controllers

2014-03-06T20:36:23+00:00

Since commit bd972688eb24
"firewire: ohci: Fix 'failed to read phy reg' on FW643 rev8",
there is a high chance that firewire-ohci fails to initialize LSI née
Agere controllers.
https://bugzilla.kernel.org/show_bug.cgi?id=65151

Peter Hurley points out the reason:  IEEE 1394a:2000 clause 5A.1 (or
IEEE 1394:2008 clause 17.2.1) say:  "The PHY shall insure that no more
than 10 ms elapse from the reassertion of LPS until the interface is
reset.  The link shall not assert LReq until the reset is complete."
In other words, the link needs to give the PHY at least 10 ms to get
the interface operational.

With just the msleep(1) in bd972688eb24, the first read_phy_reg()
during ohci_enable() may happen before the phy-link interface reset was
finished, and fail.  Due to the high variability of msleep(n) with small
n, this failure was not fully reproducible, and not apparent at all with
low CONFIG_HZ setting.

On the other hand, Peter can no longer reproduce the issue with FW643
rev8.  The read phy reg failures that happened back then may have had an
unrelated cause.  So, just revert bd972688eb24, except for the valid
comment on TSB82AA2 cards.

Reported-by: Mikhail Gavrilov
Reported-by: Jay Fenlason 
Reported-by: Clemens Ladisch 
Reported-by: Peter Hurley 
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Stefan Richter

firewire: Enable remote DMA above 4 GB

2014-01-20T00:11:13+00:00

This makes all of a machine's memory accessible to remote debugging via
FireWire, using the physical response unit (i.e. RDMA) of OHCI-1394 link
layer controllers.

This requires actual support by the controller.  The only ones currently
known to support it are Agere/LSI FW643.  Most if not all other OHCI-1394
controllers do not implement the optional Physical Upper Bound register.
With them, RDMA will continue to be limited to the lowermost 4 GB.

firewire-ohci's startup message in the kernel log is augmented to tell
whether the controller does expose more than 4 GB to RDMA.

While OHCI-1394 allows for a maximum Physical Upper Bound of
0xffff'0000'0000 (near 256 TB), this implementation sets it to
0x8000'0000'0000 (128 TB) in order to avoid interference with applications
that require interrupt-served asynchronous request reception at
respectively low addresses.

Note, this change does not switch remote DMA on.  It only increases the
range of remote access to all memory (instead of just 4 GB) whenever
remote DMA was switched on by other means.  The latter is achieved by
setting firewire-ohci's remote_dma parameter, or if the physical DMA
filter is opened through firewire-sbp2.

Derived from patch "firewire: Enable physical DMA above 4GB" by
Peter Hurley  from March 27, 2013.

Signed-off-by: Stefan Richter

firewire: ohci: Turn remote DMA support into a module parameter

2014-01-12T17:54:38+00:00

This makes it possible to debug kernel over FireWire without the need to
recompile it.

[Stefan R: changed description from "...0" to "...N"]

Cc: Dave Hansen 
Signed-off-by: Lubomir Rintel 
Signed-off-by: Stefan Richter

firewire: ohci: Fix deadlock at bus reset

2013-08-29T20:35:05+00:00

Put bus_reset_work into its own workqueue.  By doing this, forward
progress of bus_reset_work() is guaranteed if the work is switched over
to a rescuer thread.

Switching work to a rescuer thread happens if a new worker thread could
not be allocated in certain time (MAYDAY_INITIAL_TIMEOUT, typically 10
ms).  This might not be possible under high memory pressure or even on a
heavily loaded embedded system running a slow serial console.

The former deadlock occured in the following situation:
The rescuer thread ran
fw_device_init->read_config_rom->read_rom->fw_run_transaction.
fw_run_transaction blocked waiting for the completion object.
This completion object would have been completed in bus_reset_work,
but this work was never executed in the rescuer thread due to its
strictly sequential behaviour.

[Stefan R.:  Removed WQ_NON_REENTRANT flag from allocation because
it is no longer needed in current kernels.  Add it back if you backport
to kernels older than 3.7, i.e. one which does not contain dbf2576e37da
"workqueue: make all workqueues non-reentrant".  Swapped order of
destroy_workqueue and pci_unregister_driver.]

Signed-off-by: Stephan Gatzka 
Signed-off-by: Stefan Richter

firewire: ohci: Change module_pci_driver to module_init/module_exit

2013-08-29T20:30:54+00:00

This is a prerequisite to allocate a per driver self_id workqueue.
This reverts the ohci.c part of patch
fe2af11c220c7bb3a67f7aec0594811e5c59e019.

Signed-off-by: Stephan Gatzka 
Signed-off-by: Stefan Richter

firewire: ohci: beautify some macro definitions

2013-08-19T07:02:05+00:00

a) Sort device IDs by vendor -- device -- revision.

b) Write quirk flags in hexadecimal.  This affects the user-visible
output of "modinfo firewire-ohci".  Since more flags have been added
recently, it is now easier to cope with them in hexadecimal represen-
tation.  Besides, the device-specific combination of quirk flags is
shown in hexadecimal in the kernel log too.  (And firewire-sbp2
presents its own quirk flags in modinfo as hexadecimals as well.)

Signed-off-by: Stefan Richter

firewire: ohci: change confusing name of a struct member

2013-08-19T07:02:05+00:00

We have got

	struct descriptor *descriptors;
	dma_addr_t         descriptors_bus;

	dma_addr_t         buffer_bus;
	struct descriptor buffer[0];

	void      *misc_buffer;
	dma_addr_t misc_buffer_bus;

	__be32    *config_rom;
	dma_addr_t config_rom_bus;
	__be32    *next_config_rom;
	dma_addr_t next_config_rom_bus;

But then we have got

	__le32    *self_id_cpu;
	dma_addr_t self_id_bus;

Better apply the pattern of xyz vs. xyz_bus to self_id vs. self_id_bus
as well.  The _cpu suffix looks particularly weird in conversions from
little endian to CPU endian.

Signed-off-by: Stefan Richter

firewire: fix libdc1394/FlyCap2 iso event regression

2013-07-27T18:24:36+00:00

Commit 18d627113b83 (firewire: prevent dropping of completed iso packet
header data) was intended to be an obvious bug fix, but libdc1394 and
FlyCap2 depend on the old behaviour by ignoring all returned information
and thus not noticing that not all packets have been received yet.  The
result was that the video frame buffers would be saved before they
contained the correct data.

Reintroduce the old behaviour for old clients.

Tested-by: Stepan Salenikovich 
Tested-by: Josep Bosch 
Cc:  # 3.4+
Signed-off-by: Clemens Ladisch 
Signed-off-by: Stefan Richter

firewire: ohci: dump_stack() for PHY regs read/write failures

2013-04-30T18:30:16+00:00

A stack trace is an invaluable tool in determining the basis
and cause of PHY regs read/write failures.

Include PHY reg addr (and value for writes) in the diagnostic.

[Stefan R:  changed whitespace]

Signed-off-by: Peter Hurley 
Signed-off-by: Stefan Richter

firewire: ohci: Improve bus reset error messages

2013-04-30T18:30:16+00:00

Many of the error messages possible from bus_reset_work() do not
contain enough information to distinguish which error condition
occurred nor enough information to evaluate the error afterwards.

Differentiate all error conditions in bus_reset_work(); add
additional information to make error diagnosis possible.

[Stefan R:  fixed self-ID endian conversion]

Signed-off-by: Peter Hurley 
Signed-off-by: Stefan Richter