During the development period of v6.8 kernel, it became evident that there
was a lack of helper utilities to trace the initial state of bus, while
investigating certain PHYs compliant with different versions of IEEE 1394
specification.
This series of changes includes the addition of tracepoints events,
provided by 'firewire' subsystem. These events enable tracing of how
firewire core functions during bus reset and asynchronous communication
over IEEE 1394 bus.
When implementing the tracepoints events, it was found that the existing
serialization and deserialization helpers for several types of
asynchronous packets are scattered across both firewire-core and
firewire-ohci kernel modules. A set of inline functions is newly added
to address it, along with some KUnit tests, serving as the foundation for
the tracepoints events. This renders the dispersed code obsolete.
The remaining changes constitute the final steps in phasing out the usage
of deprecated PCI MSI APIs, in continuation from the previous version.
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Merge tag 'firewire-updates-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394
Pull firewire updates from Takashi Sakamoto:
"During the development period of v6.8 kernel, it became evident that
there was a lack of helper utilities to trace the initial state of
bus, while investigating certain PHYs compliant with different
versions of IEEE 1394 specification.
This series of changes includes the addition of tracepoints events,
provided by 'firewire' subsystem. These events enable tracing of how
firewire core functions during bus reset and asynchronous
communication over IEEE 1394 bus.
When implementing the tracepoints events, it was found that the
existing serialization and deserialization helpers for several types
of asynchronous packets are scattered across both firewire-core and
firewire-ohci kernel modules. A set of inline functions is newly added
to address it, along with some KUnit tests, serving as the foundation
for the tracepoints events. This renders the dispersed code obsolete.
The remaining changes constitute the final steps in phasing out the
usage of deprecated PCI MSI APIs, in continuation from the previous
version"
* tag 'firewire-updates-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394: (29 commits)
firewire: obsolete usage of *-objs in Makefile for KUnit test
firewire: core: remove flag and width from u64 formats of tracepoints events
firewire: core: fix type of timestamp for async_inbound_template tracepoints events
firewire: core: add tracepoint event for handling bus reset
Revert "firewire: core: option to log bus reset initiation"
firewire: core: add tracepoints events for initiating bus reset
firewire: ohci: obsolete OHCI_PARAM_DEBUG_BUSRESETS from debug module parameter
firewire: ohci: add bus-reset event for initial set of handled irq
firewire: core: add tracepoints event for asynchronous inbound phy packet
firewire: core/cdev: add tracepoints events for asynchronous phy packet
firewire: core: add tracepoints events for asynchronous outbound response
firewire: core: add tracepoint event for asynchronous inbound request
firewire: core: add tracepoints event for asynchronous inbound response
firewire: core: add tracepoints events for asynchronous outbound request
firewire: core: add support for Linux kernel tracepoints
firewire: core: replace local macros with common inline functions for isochronous packet header
firewire: core: add common macro to serialize/deserialize isochronous packet header
firewire: core: obsolete tcode check macros with inline functions
firewire: ohci: replace hard-coded values with common macros
firewire: ohci: replace hard-coded values with inline functions for asynchronous packet header
...
Updates to the usual drivers (ufs, lpfc, qla2xxx, mpi3mr, libsas).
The major update (which causes a conflict with block, see below) is
Christoph removing the queue limits and their associated block
helpers. The remaining patches are assorted minor fixes and
deprecated function updates plus a bit of constification.
Signed-off-by: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI updates from James Bottomley:
"Updates to the usual drivers (ufs, lpfc, qla2xxx, mpi3mr, libsas).
The major update (which causes a conflict with block, see below) is
Christoph removing the queue limits and their associated block
helpers.
The remaining patches are assorted minor fixes and deprecated function
updates plus a bit of constification"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (141 commits)
scsi: mpi3mr: Sanitise num_phys
scsi: lpfc: Copyright updates for 14.4.0.2 patches
scsi: lpfc: Update lpfc version to 14.4.0.2
scsi: lpfc: Add support for 32 byte CDBs
scsi: lpfc: Change lpfc_hba hba_flag member into a bitmask
scsi: lpfc: Introduce rrq_list_lock to protect active_rrq_list
scsi: lpfc: Clear deferred RSCN processing flag when driver is unloading
scsi: lpfc: Update logging of protection type for T10 DIF I/O
scsi: lpfc: Change default logging level for unsolicited CT MIB commands
scsi: target: Remove unused list 'device_list'
scsi: iscsi: Remove unused list 'connlist_err'
scsi: ufs: exynos: Add support for Tensor gs101 SoC
scsi: ufs: exynos: Add some pa_dbg_ register offsets into drvdata
scsi: ufs: exynos: Allow max frequencies up to 267Mhz
scsi: ufs: exynos: Add EXYNOS_UFS_OPT_TIMER_TICK_SELECT option
scsi: ufs: exynos: Add EXYNOS_UFS_OPT_UFSPR_SECURE option
scsi: ufs: dt-bindings: exynos: Add gs101 compatible
scsi: qla2xxx: Fix debugfs output for fw_resource_count
scsi: qedf: Ensure the copied buf is NUL terminated
scsi: bfa: Ensure the copied buf is NUL terminated
...
Nowadays *-objs list is just for user space programs.
This commit obsolete the usage, and simplify Makefile for firewire KUnit
tests since the tests are not composite objects.
Link: https://lore.kernel.org/r/20240508105351.532693-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The core function expects hardware drivers to call
fw_core_handle_bus_reset() when changing bus topology. The 1394 OHCI
driver calls it when handling selfID event as a result of any bus-reset.
This commit adds a tracepoints event for it.
Link: https://lore.kernel.org/r/20240501073238.72769-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
This reverts commit 6732491243045f5a7e1995b4be5f3c964b579ebd.
The former commit adds some alternative tracepoints events to replace the
reverted kernel log messages.
Link: https://lore.kernel.org/r/20240501073238.72769-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
At a commit 673249124304 ("firewire: core: option to log bus reset
initiation"), some kernel log messages were added to trace initiation of
bus reset. The kernel log messages are really helpful, while nowadays it
is not preferable just for debugging purpose. For the purpose, Linux
kernel tracepoints is more preferable.
This commit adds some alternative tracepoints events.
Link: https://lore.kernel.org/r/20240501073238.72769-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The OHCI_PARAM_DEBUG_BUSRESETS bit of debug module parameter was added at
a commit a007bb857e ("firewire: fw-ohci: conditionally log busReset
interrupts").
At the former commit, the bit becomes less meaningful, just to skip
logging.
This commit obsoletes it.
Link: https://lore.kernel.org/r/20240501073238.72769-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In the former commits, the spurious interrupt events are suppressed as
possible, by unset bus-reset event from the set of handled irq. The change
was written with the less-intrusive style, thus it firstly works at the
second time to handle the event. But it is slightly inconvenient.
This commit adds the event for the initial set of irq to handle. As a
result, the event can be handled even if it is the first time. The change
has a benefit that the OHCI_PARAM_DEBUG_BUSRESETS bit in debug module
parameter is always effective.
Tested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20240501073238.72769-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
At the former commit, a pair of tracepoints events is added to trace
asynchronous outbound phy packet. This commit adds a tracepoints event
to trace inbound phy packet. It includes transaction status as well as
the content of phy packet.
This is an example for Remote Reply Packet as a response to Remote Access
Packet sent by lsfirewirephy command in linux-firewire-utils:
async_phy_inbound: \
packet=0xffff955fc02b4e10 generation=1 status=1 timestamp=0x0619 \
first_quadlet=0x001c8208 second_quadlet=0xffe37df7
Link: https://lore.kernel.org/r/20240430001404.734657-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In IEEE 1394 bus, the type of asynchronous packet without any offset to
node address space is called as phy packet. The destination of packet is
IEEE 1394 phy itself. This type of packet is used for several purposes,
mainly for selfID at the state of bus reset, to force selection of root
node, and to adjust gap count.
This commit adds tracepoints events for the type of asynchronous outbound
packet. Like asynchronous outbound transaction packets, a pair of events
are added to trace initiation and completion of transmission.
In the case that the phy packet is sent by kernel API, the match between
the initiation and completion is not so easy, since the data of
'struct fw_packet' is allocated statically. In the case that it is sent by
userspace applications via cdev, the match is easy, since the data is
allocated per each.
This example is for Remote Access Packet by lsfirewirephy command in
linux-firewire-utils:
async_phy_outbound_initiate: \
packet=0xffff89fb34e42e78 generation=1 first_quadlet=0x00148200 \
second_quadlet=0xffeb7dff
async_phy_outbound_complete: \
packet=0xffff89fb34e42e78 generation=1 status=1 timestamp=0x0619
Link: https://lore.kernel.org/r/20240430001404.734657-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In a view of core transaction service, the asynchronous outbound response
consists of two stages; initiation and completion.
This commit adds a pair of events for the asynchronous outbound response.
The following example is for asynchronous write quadlet request as IEC
61883-1 FCP response to node 0xffc1.
async_response_outbound_initiate: \
transaction=0xffff89fa08cf16c0 generation=4 scode=2 dst_id=0xffc1 \
tlabel=25 tcode=2 src_id=0xffc0 rcode=0 \
header={0xffc16420,0xffc00000,0x0,0x0} data={}
async_response_outbound_complete: \
transaction=0xffff89fa08cf16c0 generation=4 scode=2 status=1 \
timestamp=0x0000
Link: https://lore.kernel.org/r/20240429043218.609398-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
This commit adds an event for asynchronous inbound request.
The following example is for asynchronous block write request as IEC
61883-1 FCP request from node 0xffc1.
async_request_inbound: \
transaction=0xffff89fa08cf16c0 generation=4 scode=2 status=2 \
timestamp=0x00b3 dst_id=0xffc0 tlabel=19 tcode=1 src_id=0xffc1 \
offset=0xfffff0000d00 header={0xffc04d10,0xffc1ffff,0xf0000d00,0x80000} \
data={0x19ff08,0xffff0090}
Link: https://lore.kernel.org/r/20240429043218.609398-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In the transaction of IEEE 1394, the node to receive the asynchronous
request transfers any response packet to the requester except for the
unified transaction.
This commit adds an event for the inbound packet. Note that the code to
decode the packet header is moved, against the note about the sanity
check.
The following example is for asynchronous lock response with
compare_and_swap code.
async_response_inbound: \
transaction=0xffff955fc6a07a10 generation=5 scode=2 status=1 \
timestamp=0x0089 dst_id=0xffc1 tlabel=54 tcode=11 src_id=0xffc0 \
rcode=0 header={0xffc1d9b0,0xffc00000,0x0,0x40002} data={0x50800080}
Link: https://lore.kernel.org/r/20240429043218.609398-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In a view of core transaction service, the asynchronous outbound request
consists of two stages; initiation and completion. This commit adds a pair
of event for them.
The following example is for asynchronous lock request with compare_swap
code to offset 0x'ffff'f000'0904 in node 0xffc0.
async_request_outbound_initiate: \
transaction=0xffff955fc6a07a10 generation=5 scode=2 dst_id=0xffc0 \
tlabel=54 tcode=9 src_id=0xffc1 offset=0xfffff0000904 \
header={0xffc0d990,0xffc1ffff,0xf0000904,0x80002}
data={0x80,0x940181}
async_request_outbound_complete: \
transaction=0xffff955fc6a07a10 generation=5 scode=2 status=2 \
timestamp=0xd887
Link: https://lore.kernel.org/r/20240429043218.609398-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The Linux Kernel Tracepoints framework is enough useful to trace
packet data inbound to and outbound from core.
This commit adds firewire subsystem to use the framework.
Link: https://lore.kernel.org/r/20240429043218.609398-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The packet for Asynchronous Streaming Packet includes the same header
fields as the isochronous packet has. It is helpful to have some helper
functions to serialize/deserialize them.
This commit adds such helper functions with their test.
Link: https://lore.kernel.org/r/20240428071347.409202-8-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In the helper function for logging in 1394 ohci driver includes the
hard-coded variables for transaction code. They can be replaced with
the enumerations in UAPI header.
Link: https://lore.kernel.org/r/20240428071347.409202-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In both core and 1394 OHCI driver, some hard-coded values and macros are
used to serialize/deserialize the header of asynchronous packets. It is
inconvenient to reuse them.
This commit adds some helper inline functions with their tests for the
purpose.
Link: https://lore.kernel.org/r/20240428071347.409202-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The usage of the pair of pci_enable_msi() and pci_disable_msi() is
deprecated.
This commit uses the preferred pair of API for the purpose. The call of
pci_alloc_irq_vectors() can have a subeffect to change the return value
of pci_dev_msi_enabled().
Link: https://lore.kernel.org/r/20240331135037.191479-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Nowadays request_irq() is a wrapper of request_threaded_irq(). The IRQ
handler of 1394 ohci driver has never been optimized yet, while it is
a good preparation for the future work to replace the latter.
This commit replaces the former.
Link: https://lore.kernel.org/r/20240331135037.191479-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Add a debug parameter to firewire-core, analogous to the one in
firewire-ohci. When this is set to 1, log when we schedule, delay, or
initiate a bus reset. Since FireWire bus resets can originate from any
node on the bus, specific logging of the resets we initiate provides
additional insight.
Signed-off-by: Adam Goldman <adamg@pobox.com>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
1394 OHCI driver generates packet data for the response subaction to the
request subaction to some local registers. In the case, the driver should
assign timestamp to them by itself.
This commit fulfills the timestamp for the subaction.
Cc: stable@vger.kernel.org
Fixes: dcadfd7f7c ("firewire: core: use union for callback of transaction completion")
Link: https://lore.kernel.org/r/20240429084709.707473-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Ensure that packet_buffer_get respects the user_length provided. If
the length of the head packet exceeds the user_length, packet_buffer_get
will now return 0 to signify to the user that no data were read
and a larger buffer size is required. Helps prevent user space overflows.
Signed-off-by: Thanassis Avgerinos <thanassis.avgerinos@gmail.com>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Switch to the ->device_configure method instead of ->slave_configure and
update the block limits on the passed in queue_limits instead of using the
per-limit accessors.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240409143748.980206-14-hch@lst.de
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Get drivers out of the business of having to call the block layer DMA
alignment limits helpers themselves.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240409143748.980206-8-hch@lst.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In the FireWire OHCI interrupt handler, if a bus reset interrupt has
occurred, mask bus reset interrupts until bus_reset_work has serviced and
cleared the interrupt.
Normally, we always leave bus reset interrupts masked. We infer the bus
reset from the self-ID interrupt that happens shortly thereafter. A
scenario where we unmask bus reset interrupts was introduced in 2008 in
a007bb857e0b26f5d8b73c2ff90782d9c0972620: If
OHCI_PARAM_DEBUG_BUSRESETS (8) is set in the debug parameter bitmask, we
will unmask bus reset interrupts so we can log them.
irq_handler logs the bus reset interrupt. However, we can't clear the bus
reset event flag in irq_handler, because we won't service the event until
later. irq_handler exits with the event flag still set. If the
corresponding interrupt is still unmasked, the first bus reset will
usually freeze the system due to irq_handler being called again each
time it exits. This freeze can be reproduced by loading firewire_ohci
with "modprobe firewire_ohci debug=-1" (to enable all debugging output).
Apparently there are also some cases where bus_reset_work will get called
soon enough to clear the event, and operation will continue normally.
This freeze was first reported a few months after a007bb85 was committed,
but until now it was never fixed. The debug level could safely be set
to -1 through sysfs after the module was loaded, but this would be
ineffectual in logging bus reset interrupts since they were only
unmasked during initialization.
irq_handler will now leave the event flag set but mask bus reset
interrupts, so irq_handler won't be called again and there will be no
freeze. If OHCI_PARAM_DEBUG_BUSRESETS is enabled, bus_reset_work will
unmask the interrupt after servicing the event, so future interrupts
will be caught as desired.
As a side effect to this change, OHCI_PARAM_DEBUG_BUSRESETS can now be
enabled through sysfs in addition to during initial module loading.
However, when enabled through sysfs, logging of bus reset interrupts will
be effective only starting with the second bus reset, after
bus_reset_work has executed.
Signed-off-by: Adam Goldman <adamg@pobox.com>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In the case of firewire core function, the caller of show functions for
device attributes is not only sysfs user, but also device initialization.
This commit adds memo about it against the typical assumption that the
functions are just dedicated to sysfs user.
Link: https://lore.kernel.org/lkml/20240318091759.678326-1-o-takashi@sakamocchi.jp/
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Per filesystems/sysfs.rst, show() should only use sysfs_emit()
or sysfs_emit_at() when formatting the value to be returned to user space.
coccinelle complains that there are still a couple of functions that use
snprintf(). Convert them to sysfs_emit().
> drivers/firewire/core-device.c:326:8-16: WARNING: please use sysfs_emit or sysfs_emit_at
No functional change intended
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/r/20240122053942.80648-2-lizhijian@fujitsu.com
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Per Documentation/filesystems/sysfs.rst:
> sysfs allocates a buffer of size (PAGE_SIZE) and passes it to the
> method.
So we can kill the unnecessary buf check safely.
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/r/20240122053942.80648-1-lizhijian@fujitsu.com
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Commit 5a95f1ded2 ("firewire: ohci: use devres for requested IRQ")
also removed the call to free_irq() in pci_remove(), leading to a
leftover irq of devm_request_irq() at pci_disable_msi() in pci_remove()
when unbinding the driver from the device
remove_proc_entry: removing non-empty directory 'irq/136', leaking at
least 'firewire_ohci'
Call Trace:
? remove_proc_entry+0x19c/0x1c0
? __warn+0x81/0x130
? remove_proc_entry+0x19c/0x1c0
? report_bug+0x171/0x1a0
? console_unlock+0x78/0x120
? handle_bug+0x3c/0x80
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? remove_proc_entry+0x19c/0x1c0
unregister_irq_proc+0xf4/0x120
free_desc+0x3d/0xe0
? kfree+0x29f/0x2f0
irq_free_descs+0x47/0x70
msi_domain_free_locked.part.0+0x19d/0x1d0
msi_domain_free_irqs_all_locked+0x81/0xc0
pci_free_msi_irqs+0x12/0x40
pci_disable_msi+0x4c/0x60
pci_remove+0x9d/0xc0 [firewire_ohci
01b483699bebf9cb07a3d69df0aa2bee71db1b26]
pci_device_remove+0x37/0xa0
device_release_driver_internal+0x19f/0x200
unbind_store+0xa1/0xb0
remove irq with devm_free_irq() before pci_disable_msi()
also remove it in fail_msi: of pci_probe() as this would lead to
an identical leak
Cc: stable@vger.kernel.org
Fixes: 5a95f1ded2 ("firewire: ohci: use devres for requested IRQ")
Signed-off-by: Edmund Raile <edmund.raile@proton.me>
Link: https://lore.kernel.org/r/20240229144723.13047-2-edmund.raile@proton.me
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
When resetting the bus after a gap count error, use a long rather than
short bus reset.
IEEE 1394-1995 uses only long bus resets. IEEE 1394a adds the option of
short bus resets. When video or audio transmission is in progress and a
device is hot-plugged elsewhere on the bus, the resulting bus reset can
cause video frame drops or audio dropouts. Short bus resets reduce or
eliminate this problem. Accordingly, short bus resets are almost always
preferred.
However, on a mixed 1394/1394a bus, a short bus reset can trigger an
immediate additional bus reset. This double bus reset can be interpreted
differently by different nodes on the bus, resulting in an inconsistent gap
count after the bus reset. An inconsistent gap count will cause another bus
reset, leading to a neverending bus reset loop. This only happens for some
bus topologies, not for all mixed 1394/1394a buses.
By instead sending a long bus reset after a gap count inconsistency, we
avoid the doubled bus reset, restoring the bus to normal operation.
Signed-off-by: Adam Goldman <adamg@pobox.com>
Link: https://sourceforge.net/p/linux1394/mailman/message/58741624/
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
If we are bus manager and the bus has inconsistent gap counts, send a
bus reset immediately instead of trying to read the root node's config
ROM first. Otherwise, we could spend a lot of time trying to read the
config ROM but never succeeding.
This eliminates a 50+ second delay before the FireWire bus is usable after
a newly connected device is powered on in certain circumstances.
The delay occurs if a gap count inconsistency occurs, we are not the root
node, and we become bus manager. One scenario that causes this is with a TI
XIO2213B OHCI, the first time a Sony DSR-25 is powered on after being
connected to the FireWire cable. In this configuration, the Linux box will
not receive the initial PHY configuration packet sent by the DSR-25 as IRM,
resulting in the DSR-25 having a gap count of 44 while the Linux box has a
gap count of 63.
FireWire devices have a gap count parameter, which is set to 63 on power-up
and can be changed with a PHY configuration packet. This determines the
duration of the subaction and arbitration gaps. For reliable communication,
all nodes on a FireWire bus must have the same gap count.
A node may have zero or more of the following roles: root node, bus manager
(BM), isochronous resource manager (IRM), and cycle master. Unless a root
node was forced with a PHY configuration packet, any node might become root
node after a bus reset. Only the root node can become cycle master. If the
root node is not cycle master capable, the BM or IRM should force a change
of root node.
After a bus reset, each node sends a self-ID packet, which contains its
current gap count. A single bus reset does not change the gap count, but
two bus resets in a row will set the gap count to 63. Because a consistent
gap count is required for reliable communication, IEEE 1394a-2000 requires
that the bus manager generate a bus reset if it detects that the gap count
is inconsistent.
When the gap count is inconsistent, build_tree() will notice this after the
self identification process. It will set card->gap_count to the invalid
value 0. If we become bus master, this will force bm_work() to send a bus
reset when it performs gap count optimization.
After a bus reset, there is no bus manager. We will almost always try to
become bus manager. Once we become bus manager, we will first determine
whether the root node is cycle master capable. Then, we will determine if
the gap count should be changed. If either the root node or the gap count
should be changed, we will generate a bus reset.
To determine if the root node is cycle master capable, we read its
configuration ROM. bm_work() will wait until we have finished trying to
read the configuration ROM.
However, an inconsistent gap count can make this take a long time.
read_config_rom() will read the first few quadlets from the config ROM. Due
to the gap count inconsistency, eventually one of the reads will time out.
When read_config_rom() fails, fw_device_init() calls it again until
MAX_RETRIES is reached. This takes 50+ seconds.
Once we give up trying to read the configuration ROM, bm_work() will wake
up, assume that the root node is not cycle master capable, and do a bus
reset. Hopefully, this will resolve the gap count inconsistency.
This change makes bm_work() check for an inconsistent gap count before
waiting for the root node's configuration ROM. If the gap count is
inconsistent, bm_work() will immediately do a bus reset. This eliminates
the 50+ second delay and rapidly brings the bus to a working state.
I considered that if the gap count is inconsistent, a PHY configuration
packet might not be successful, so it could be desirable to skip the PHY
configuration packet before the bus reset in this case. However, IEEE
1394a-2000 and IEEE 1394-2008 say that the bus manager may transmit a PHY
configuration packet before a bus reset when correcting a gap count error.
Since the standard endorses this, I decided it's safe to retain the PHY
configuration packet transmission.
Normally, after a topology change, we will reset the bus a maximum of 5
times to change the root node and perform gap count optimization. However,
if there is a gap count inconsistency, we must always generate a bus reset.
Otherwise the gap count inconsistency will persist and communication will
be unreliable. For that reason, if there is a gap count inconstency, we
generate a bus reset even if we already reached the 5 reset limit.
Signed-off-by: Adam Goldman <adamg@pobox.com>
Reference: https://sourceforge.net/p/linux1394/mailman/message/58727806/
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
As the last part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when
constructing modalias for unit device. The change brings loss of backward
compatibility since it can fill model field ('mo') which is 0 at current
implementation in the case. However, we can be optimistic against
regression for unit drivers in kernel, due to some points:
1. ALSA drivers for audio and music units use the model fields to match
device, however all of supported devices does not have such legacy
layout.
2. the other unit drivers (e.g. sbp2) does not use the model field to
match device.
The rest of concern is user space application. The most of applications
just take care of node device and does not use the modalias of unit
device, thus the change does not affect to them. But systemd project is
known to get affects from the change since it includes hwdb to take udev
to configure fw character device conveniently. I have a plan to work for
systemd so that the access permission of character device could be kept
across the change.
Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-9-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model_name'
attribute appears in node device, however it is probable to see the other
types of descriptor leaf if the vendor directory includes.
Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-8-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model' attribute
appears in node device, however it is probable to see the other types of
immediate values if the vendor directory includes.
Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Some legacy devices have configuration ROM against standard AV/C device.
They have vendor directory to store model identifier. It is described in
annex of the following document.
- Configuration ROM for AV/C Devices 1.0 (Dec. 12, 2000, 1394 Trading
Association)
In the case, current implementation of core function does not detect the
model identifier, thus device attributes and modalias of unit have lack of
it. Another KUnit test is required for the case, and this commit is for
the purpose.
The following output is the parse result for the hard-coded data, by
config-rom-pretty-printer in linux-firewire-utils
(https://git.kernel.org/pub/scm/utils/ieee1394/linux-firewire-utils.git/).
The data is written by my hand.
$ config-rom-pretty-printer < /tmp/rom.img
ROM header and bus information block
-----------------------------------------------------------------
1024 04199fe7 bus_info_length 4, crc_length 25, crc 40935
1028 31333934 bus_name "1394"
1032 e0644000 irmc 1, cmc 1, isc 1, bmc 0, cyc_clk_acc 100, max_rec 4 (32)
1036 00112233 company_id 001122 |
1040 44556677 device_id 220189779575 | EUI-64 4822678189205111
root directory
-----------------------------------------------------------------
1044 0005dace directory_length 5, crc 56014
1048 03012345 vendor
1052 0c0083c0 node capabilities: per IEEE 1394
1056 8d000009 --> eui-64 leaf at 1092
1060 d1000002 --> unit directory at 1068
1064 c3000004 --> vendor directory at 1080
unit directory at 1068
-----------------------------------------------------------------
1068 0002e107 directory_length 2, crc 57607
1072 12abcdef specifier id
1076 13543210 version
vendor directory at 1080
-----------------------------------------------------------------
1080 0002cb73 directory_length 2, crc 52083
1084 17fedcba model
1088 81000004 --> descriptor leaf at 1104
eui-64 leaf at 1092
-----------------------------------------------------------------
1092 00026dc1 leaf_length 2, crc 28097
1096 00112233 company_id 001122 |
1100 44556677 device_id 220189779575 | EUI-64 4822678189205111
descriptor leaf at 1104
-----------------------------------------------------------------
1104 00050e84 leaf_length 5, crc 3716
1108 00000000 textual descriptor
1112 00000000 minimal ASCII
1116 41424344 "ABCD"
1120 45464748 "EFGH"
1124 494a0000 "IJ"
Link: https://lore.kernel.org/r/20231221134849.603857-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
At present, core function can handle node which has configuration ROM
similar to standard AV/C device somehow. The standard layout of
configuration ROM is described in the following document.
- Configuration ROM for AV/C Devices 1.0 (Dec. 12, 2000, 1394 Trading
Association)
This commit adds a KUnit test for the above case.
The following output is the parse result for the hard-coded data, by
config-rom-pretty-printer in linux-firewire-utils
(https://git.kernel.org/pub/scm/utils/ieee1394/linux-firewire-utils.git/).
$ config-rom-pretty-printer < /tmp/rom.img
ROM header and bus information block
-----------------------------------------------------------------
1024 0404eabf bus_info_length 4, crc_length 4, crc 60095
1028 31333934 bus_name "1394"
1032 e0646102 irmc 1, cmc 1, isc 1, bmc 0, cyc_clk_acc 100, max_rec 6 (128)
1036 ffffffff company_id ffffff |
1040 ffffffff device_id 1099511627775 | EUI-64 18446744073709551615
root directory
-----------------------------------------------------------------
1044 00063287 directory_length 6, crc 12935
1048 03ffffff vendor
1052 8100000a --> descriptor leaf at 1092
1056 17ffffff model
1060 8100000e --> descriptor leaf at 1116
1064 0c0083c0 node capabilities: per IEEE 1394
1068 d1000001 --> unit directory at 1072
unit directory at 1072
-----------------------------------------------------------------
1072 0004442d directory_length 4, crc 17453
1076 1200a02d specifier id
1080 13010001 version
1084 17ffffff model
1088 81000007 --> descriptor leaf at 1116
descriptor leaf at 1092
-----------------------------------------------------------------
1092 0005c915 leaf_length 5, crc 51477
1096 00000000 textual descriptor
1100 00000000 minimal ASCII
1104 56656e64 "Vend"
1108 6f72204e "or N"
1112 616d6500 "ame"
descriptor leaf at 1116
-----------------------------------------------------------------
1116 00057f16 leaf_length 5, crc 32534
1120 00000000 textual descriptor
1124 00000000 minimal ASCII
1128 4d6f6465 "Mode"
1132 6c204e61 "l Na"
1136 6d650000 "me"
Link: https://lore.kernel.org/r/20231221134849.603857-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The traverse over CSR space results in attributes of node and unit
devices. Any test of the traverse is useful.
This commit adds a skeleton of KUnit test for the purpose.
Link: https://lore.kernel.org/r/20231221134849.603857-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In IEEE 1394 specification, the size of bus information block of
configuration ROM is fixed to 5, thus the offset of root directory is 5.
Current implementation to handle device structures has the hard-coded
offset.
This commit replaces the offset with macro.
Link: https://lore.kernel.org/r/20231221134849.603857-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
