After bus reset, isochronous resource manager releases all of allocated
isochronous resources. The nodes to transfer isochronous packet should
request reallocation of the resources.
However, between the bus-reset and invocation of 'struct fw_driver.update'
handler, ALSA PCM application can detect this situation by XRUN because
the target device cancelled to transmit packets once bus-reset occurs.
Due to the above mechanism, ALSA fireface driver just stops packet
streaming in the update handler, thus pcm.prepare handler should
request the reallocation.
This commit requests the reallocation in pcm.prepare callback when
bus generation is changed.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Once allocated, isochronous resources are available for packet
streaming, even if the streaming is cancelled. For this reason,
current implementation handles allocation of the resources and
starting packet streaming at the same time. However, this brings
complicated procedure to start packet streaming.
This commit separates the allocation and starting. The allocation is
done in pcm.hw_params callback and available till pcm.hw_free callback.
Even if any XRUN occurs, pcm.prepare callback is done to restart
packet streaming without releasing/allocating the resources.
There are two points to stop packet streaming; in pcm.hw_params and
pcm.prepare callbacks. The former point is a case that packet streaming
is already started for any MIDI substream then packet streaming is
requested with different sampling transfer frequency for any PCM
substream. The latter point is cases of any XRUN or packet queueing
error.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is a part of preparation to perform allocation/release
of isochronous resources in pcm.hw_params/hw_free callbacks.
This commit adds a helper function to allocate isochronous resources,
separated from operations to start packet streaming, I note that some
dice-based devices have two pair of endpoints for isochronous packet
straeming.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is a part of preparation to perform allocation/release
of isochronous resources in pcm.hw_params/hw_free callbacks.
There're three points to finish packet streaming but no helper
functions for common operations for it. This commit adds a helper
function for operations to finish packet streaming.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The pairs of pcm.hw_params callbacks and .hw_free callbacks for both
direction have no differences.
This commit unifies the pairs.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
After bus reset, isochronous resource manager releases all of allocated
isochronous resources. The nodes to transfer isochronous packet should
request reallocation of the resources.
However, between the bus-reset and invocation of 'struct fw_driver.update'
handler, ALSA PCM application can detect this situation by XRUN because
the target device cancelled to transmit packets once bus-reset occurs.
Due to the above mechanism, ALSA fireface driver just stops packet
streaming in the update handler, thus pcm.prepare handler should
request the reallocation.
This commit requests the reallocation in pcm.prepare callback when
bus generation is changed.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Once allocated, isochronous resources are available for packet
streaming, even if the streaming is cancelled. For this reason,
current implementation handles allocation of the resources and
starting packet streaming at the same time. However, this brings
complicated procedure to start packet streaming.
This commit separates the allocation and starting. The allocation is
done in pcm.hw_params callback and available till pcm.hw_free callback.
Even if any XRUN occurs, pcm.prepare callback is done to restart
packet streaming without releasing/allocating the resources.
There are two points to stop packet streaming; in pcm.hw_params and
pcm.prepare callbacks. The former point is a case that packet streaming
is already started for any MIDI substream then packet streaming is
requested with different sampling transfer frequency for any PCM
substream. The latter point is cases of any XRUN or packet queueing
error.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is a part of preparation to perform allocation/release
of isochronous resources in pcm.hw_params/hw_free callbacks.
All of models in Digidesign Digi00x family have the same formation of
data channels in isochronous packet for both directions. This commit
simplifies allocation of isochronous resources in this point.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is a part of preparation to perform allocation/release
of isochronous resources in pcm.hw_params/hw_free callbacks.
The caller of begin_session() calls finish_session() in its error path,
thus no need to call finish_session() in error path of begin_session().
This commit simplifies error path of begin_session().
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is a part of preparation to perform allocation/release
of isochronous resources in pcm.hw_params/hw_free callbacks.
The operation to finish packet streaming corresponds to stopping
isochronous contexts. This commit applies code refactoring to
move codes to stop into a helper function to finish the session.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is a part of preparation to perform allocation/release
of isochronous resources in pcm.hw_params/hw_free callbacks.
The registration of isochronous channels is done just after allocation
of isochronous resources. This commit separates the registration just
before starting packet streaming.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The OS is expected to write all bits to MCA_CTL for each bank,
thus enabling error reporting in all banks. However, some banks
may be unused in which case the registers for such banks are
Read-as-Zero/Writes-Ignored. Also, the OS may avoid setting some control
bits because of quirks, etc.
A bank can be considered uninitialized if the MCA_CTL register returns
zero. This is because either the OS did not write anything or because
the hardware is enforcing RAZ/WI for the bank.
Set a bank's init value based on if the control bits are set or not in
hardware. Return an error code in the sysfs interface for uninitialized
banks.
Do a final bank init check in a separate function which is not part of
any user-controlled code flows. This is so a user may enable/disable a
bank during runtime without having to restart their system.
[ bp: Massage a bit. Discover bank init state at boot. ]
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "x86@kernel.org" <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190607201752.221446-6-Yazen.Ghannam@amd.com
The number of MCA banks is provided per logical CPU. Historically, this
number has been the same across all CPUs, but this is not an
architectural guarantee. Future AMD systems may have MCA bank counts
that vary between logical CPUs in a system.
This issue was partially addressed in
006c077041 ("x86/mce: Handle varying MCA bank counts")
by allocating structures using the maximum number of MCA banks and by
saving the maximum MCA bank count in a system as the global count. This
means that some extra structures are allocated. Also, this means that
CPUs will spend more time in the #MC and other handlers checking extra
MCA banks.
Thus, define the number of MCA banks as a per-CPU variable.
[ bp: Make mce_num_banks an unsigned int. ]
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "x86@kernel.org" <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190607201752.221446-5-Yazen.Ghannam@amd.com
On legacy systems, the addresses of the MCA_MISC* registers need to be
recursively discovered based on a Block Pointer field in the registers.
On Scalable MCA systems, the register space is fixed, and particular
addresses can be derived by regular offsets for bank and register type.
This fixed address space includes the MCA_MISC* registers.
MCA_MISC0 is always available for each MCA bank. MCA_MISC1 through
MCA_MISC4 are considered available if MCA_MISC0[BlkPtr]=1.
Cache the value of MCA_MISC0[BlkPtr] for each bank and per CPU. This
needs to be done only during init. The values should be saved per CPU
to accommodate heterogeneous SMCA systems.
Redo smca_get_block_address() to directly return the block addresses.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "x86@kernel.org" <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190607201752.221446-4-Yazen.Ghannam@amd.com
Current AMD systems have unique MCA banks per logical CPU even though
the type of the banks may all align to the same bank number. Each CPU
will have control of a set of MCA banks in the hardware and these are
not shared with other CPUs.
For example, bank 0 may be the Load-Store Unit on every logical CPU, but
each bank 0 is a unique structure in the hardware. In other words, there
isn't a *single* Load-Store Unit at MCA bank 0 that all logical CPUs
share.
This idea extends even to non-core MCA banks. For example, CPU0 and CPU4
may see a Unified Memory Controller at bank 15, but each CPU is actually
seeing a unique hardware structure that is not shared with other CPUs.
Because the MCA banks are all unique hardware structures, it would be
good to control them in a more granular way. For example, if there is a
known issue with the Floating Point Unit on CPU5 and a user wishes to
disable an error type on the Floating Point Unit, then it would be good
to do this only for CPU5 rather than all CPUs.
Also, future AMD systems may have heterogeneous MCA banks. Meaning
the bank numbers may not necessarily represent the same types between
CPUs. For example, bank 20 visible to CPU0 may be a Unified Memory
Controller and bank 20 visible to CPU4 may be a Coherent Slave. So
granular control will be even more necessary should the user wish to
control specific MCA banks.
Split the device attributes from struct mce_bank leaving only the MCA
bank control fields.
Make struct mce_banks[] per_cpu in order to have more granular control
over individual MCA banks in the hardware.
Allocate the device attributes statically based on the maximum number of
MCA banks supported. The sysfs interface will use as many as needed per
CPU. Currently, this is set to mca_cfg.banks, but will be changed to a
per_cpu bank count in a future patch.
Allocate the MCA control bits statically. This is in order to avoid
locking warnings when memory is allocated during secondary CPUs' init
sequences.
Also, remove the now unnecessary return values from
__mcheck_cpu_mce_banks_init() and __mcheck_cpu_cap_init().
Redo the sysfs store/show functions to handle the per_cpu mce_banks[].
[ bp: s/mce_banks_percpu/mce_banks_array/g ]
[ Locking issue reported by ]
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "x86@kernel.org" <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190607201752.221446-3-Yazen.Ghannam@amd.com
All drivers add all their connectors so there's no need to keep around an
array of available connectors. Instead we just put the useable (not
writeback) connectors in a temporary array using
drm_client_for_each_connector_iter() everytime we probe the outputs.
Other places where it's necessary to look at the connectors, we just
iterate over them using the same iterator function.
Rename functions which signature is changed since they will be moved to
drm_client in a later patch.
v6: Improve commit message (Sam Ravnborg)
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190608152657.36613-2-noralf@tronnes.org
If the leftmost parent node of the tree has does not have a child
on the left side, then trie_get_next_key (and bpftool map dump) will
not look at the child on the right. This leads to the traversal
missing elements.
Lookup is not affected.
Update selftest to handle this case.
Reproducer:
bpftool map create /sys/fs/bpf/lpm type lpm_trie key 6 \
value 1 entries 256 name test_lpm flags 1
bpftool map update pinned /sys/fs/bpf/lpm key 8 0 0 0 0 0 value 1
bpftool map update pinned /sys/fs/bpf/lpm key 16 0 0 0 0 128 value 2
bpftool map dump pinned /sys/fs/bpf/lpm
Returns only 1 element. (2 expected)
Fixes: b471f2f1de ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE")
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
size = sizeof(struct foo) + count * sizeof(struct boo);
instance = devm_kzalloc(dev, size, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);
Notice that, in this case, variable alloc_sz is not necessary, hence it
is removed.
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Armada 7040-db USB ports deliver 500mA by default while they
could deliver up to 900mA (usually, for USB3 devices).
The board embeds a GPIO controlled regulator on each port which can be
configured to deliver each amount of current.
Add a vin-supply property to the USB3 Vbus nodes for this purpose. The
regulator will be automatically 'enabled', ie. set to limit at 900mA
instead of 500mA.
Suggested-by: Alex Leibovich <alexl@marvell.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
csky_mpintc_handler()
->handle_domain_irq()
->irq_exit()
->invoke_softirq()
->__do_softirq()
->local_irq_enable()
If new interrupt coming, it'll get into interrupt trap before return to
csky_mpintc_handler(). So there is no need loop in csky_mpintc_handler.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Add trigger type setting for csky,mpintc. The driver also could
support #interrupt-cells <1> and it wouldn't invalidate existing
DTs. Here we only show the complete format.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Rob Herring <robh+dt@kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Support 4 triger types:
- IRQ_TYPE_LEVEL_HIGH
- IRQ_TYPE_LEVEL_LOW
- IRQ_TYPE_EDGE_RISING
- IRQ_TYPE_EDGE_FALLING
All of above could be set in DeviceTree file and it still compatible
with the old DeviceTree format.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
While there was a git repository used for the mvebu subsystem since many
years, it was not documented. let's add it.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
The irq_chip .name field should contain the device's class (not
instance) name, while .parent_device should point to the device itself.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The irq_chip .name field should contain the device's class (not
instance) name, while .parent_device should point to the device itself.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The Meson-G12A SoC uses the same GPIO interrupt controller IP block as the
other Meson SoCs, A totle of 100 pins can be spied on, which is the sum of:
- 223:100 undefined (no interrupt)
- 99:97 3 pins on bank GPIOE
- 96:77 20 pins on bank GPIOX
- 76:61 16 pins on bank GPIOA
- 60:53 8 pins on bank GPIOC
- 52:37 16 pins on bank BOOT
- 36:28 9 pins on bank GPIOH
- 27:12 16 pins on bank GPIOZ
- 11:0 12 pins in the AO domain
Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com>
Signed-off-by: Jianxin Pan <jianxin.pan@amlogic.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Enable compile-testing for all Renesas interrupt controller drivers,
except for RENESAS_H8300H_INTC. The latter relies on a function
(ctrl_bclr()) that is not available on other architectures.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Add support for Amazon Graviton custom variant of GICv2m, where the message
is encoded using the MSI message address, as opposed to standard
GICv2m, where the SPI number is encoded in the MSI message data.
In addition, the Graviton flavor of GICv2m is used along GICv3 (and not
GICv2).
Co-developed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Zeev Zilberman <zeev@amazon.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The Emagic Unitor 8 does not provide iManufacturer and iProduct fields
in its device descriptor. These fields are used by alsa to make build the
device name. Thus uncomment the .product-name in the quirks-table.
Without this change the device shows up as 'USB Device 0x86a:0x01'.
Output of lsusb and amidi:
https://gist.github.com/ensonic/7820a102e91f31575be355da2b6b33bc
Signed-off-by: Stefan Sauer <ensonic@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Check for exact and correct return value to snd_i2c_sendbytes
call for EWS/DMX 6Fire (snd_ice1712).
Fixes a systemic error on every boot starting from kernel 5.1
onwards to snd_ice1712 driver ("cannot send pca") on Terratec
EWS/DMX 6Fire PCI soundcards.
Check for exact and correct return value to snd_i2c_sendbytes
call for EWS/DMX 6Fire (snd_ice1712).
Fixes a systemic error on every boot to snd_ice1712 driver
("cannot send pca") on Terratec EWS/DMX 6Fire PCI soundcards.
Fixes: c99776cc40 ("ALSA: ice1712: fix a missing check of snd_i2c_sendbytes")
Signed-off-by: Rui Nuno Capela <rncbc@rncbc.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Associated pci_epf_bar structure is needed in pci_epc_clear_bar() to
clear a BAR correctly but it is reset in pci_epf_free_space() (that
is called first) which results in pci_epc_clear_bar() failure.
Reorder the pci_epc_clear_bar()/pci_epf_free_space() calls execution
to fix the issue.
Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
[lorenzo.pieralisi@arm.com: reworded the commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Always skip odd BAR when skipping 64bit BARs in pci_epf_test_set_bar()
and pci_epf_test_alloc_space() otherwise pci_epf_test_set_bar() will
call pci_epc_set_bar() on an odd loop index when skipping reserved 64bit
BAR.
Moreover, pci_epf_test_alloc_space() will call pci_epf_alloc_space() on
bind for an odd loop index when BAR is 64bit but leaks on subsequent
unbind by not calling pci_epf_free_space().
Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com>
PCI endpoint test function code should honor the .bar_fixed_size parameter
from underlying endpoint controller drivers or results may be unexpected.
In pci_epf_test_alloc_space(), check if BAR being used for test
register space is a fixed size BAR. If so, allocate the required fixed
size.
Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Set endpoint controller pointer to NULL in pci_epc_remove_epf()
to avoid -EBUSY on subsequent call to pci_epc_add_epf().
Add a check for NULL endpoint function pointer.
Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Stanton SCS.1m can transfer isochronous packet with Multi Bit Linear
Audio data channels, therefore it allows software to capture PCM
substream. However, ALSA oxfw driver doesn't.
This commit changes the driver to add one PCM substream for capture
direction.
Fixes: de5126cc3c ("ALSA: oxfw: add stream format quirk for SCS.1 models")
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The pairs of pcm.hw_params callbacks and .hw_free callbacks for both
direction have no differences.
This commit unifies the pairs.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The operation to finish packet streaming corresponds to stopping
isochronous contexts.
This commit applies code refactoring to move codes to stop into
a helper function to finish the session.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
After bus reset, isochronous resource manager releases all of allocated
isochronous resources. The nodes to restart packet streaming should
request reallocation of the resources.
However, between the bus-reset and invocation of 'struct fw_driver.update'
handler, ALSA PCM application can detect this situation by XRUN because
the target device cancelled to transmit packets once bus-reset occurs.
Due to the above mechanism, ALSA fireface driver just stops packet
streaming in the update handler, thus pcm.prepare handler should
request the reallocation.
This commit requests the reallocation in pcm.prepare callback when
bus generation is changed.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
