Move the calculations of values after the allocation in case the
allocation fails. This avoids wasting effort in the rare case that it
fails, but more importantly saves us extra logic to release the tty
ref.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull libata fixes from Tejun Heo:
"Two trivial fixes - one for a bug in the allocation failure path and
the other a compiler warning fix"
* 'for-4.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
ata: sata_mv: fix mis-conversion in mv_write_cached_reg()
ata: fix return value check in ahci_seattle_get_port_info()
Pull HID fix from Jiri Kosina:
"Regression fix for multitouch palm rejection from Allen Hung"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: multitouch: enable palm rejection for Windows Precision Touchpad
Revert "HID: multitouch: enable palm rejection if device implements confidence usage"
The formats are interleaved with the YUV packed and miscellaneous
formats, making the result confusing especially with the YUV444 format
being packed and not planar like YUV410 or YUV420. Move them to their
own group as the 2 planes or 3 non-contiguous planes formats to clarify
the header.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diag intends to broadcast tcp_sk and udp_sk socket destruction.
Testing sk->sk_protocol for IPPROTO_TCP/IPPROTO_UDP alone is not
sufficient for this. Raw sockets can have the same type.
Add a test for sk->sk_type.
Fixes: eb4cb00852 ("sock_diag: define destruction multicast groups")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix rcar_vin_try_fmt's use of an inappropriate pad number when calling
the subdev set_fmt function - for the ADV7612, IDs should be non-zero.
Signed-off-by: William Towle <william.towle@codethink.co.uk>
Reviewed-by: Rob Taylor <rob.taylor@codethink.co.uk>
[ulrich.hecht+renesas@gmail.com: adapted to rcar-vin rewrite]
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Add detection of source pad number for drivers aware of the media controller
API, so that rcar-vin can create device nodes to support modern drivers such
as adv7604.c (for HDMI on Lager) and the converted adv7180.c (for composite)
underneath.
Building rcar_vin gains a dependency on CONFIG_MEDIA_CONTROLLER, in
line with requirements for building the drivers associated with it.
Signed-off-by: William Towle <william.towle@codethink.co.uk>
Signed-off-by: Rob Taylor <rob.taylor@codethink.co.uk>
[ulrich.hecht+renesas@gmail.com: adapted to rcar-vin rewrite]
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
The bridge is falsly dropping ipv6 mulitcast packets if there is:
1. No ipv6 address assigned on the brigde.
2. No external mld querier present.
3. The internal querier enabled.
When the bridge fails to build mld queries, because it has no
ipv6 address, it slilently returns, but keeps the local querier enabled.
This specific case causes confusing packet loss.
Ipv6 multicast snooping can only work if:
a) An external querier is present
OR
b) The bridge has an ipv6 address an is capable of sending own queries
Otherwise it has to forward/flood the ipv6 multicast traffic,
because snooping cannot work.
This patch fixes the issue by adding a flag to the bridge struct that
indicates that there is currently no ipv6 address assinged to the bridge
and returns a false state for the local querier in
__br_multicast_querier_exists().
Special thanks to Linus Lüssing.
Fixes: d1d81d4c3d ("bridge: check return value of ipv6_dev_get_saddr()")
Signed-off-by: Daniel Danzberger <daniel@dd-wrt.com>
Acked-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
The usage Confidence is mandary to Windows Precision Touchpad devices. If
it is examined in input_mapping on a WIndows Precision Touchpad, a new add
quirk MT_QUIRK_CONFIDENCE desgned for such devices will be applied to the
device. A touch with the confidence bit is not set is determined as
invalid.
Tested on Dell XPS13 9343
Cc: stable@vger.kernel.org # v4.5+
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Andy Lutomirski <luto@kernel.org> # XPS 13 9350, BIOS 1.4.3
Signed-off-by: Allen Hung <allen_hung@dell.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This reverts commit 25a84db15b ("HID: multitouch: enable palm rejection
if device implements confidence usage")
The commit enables palm rejection for Win8 Precision Touchpad devices but
the quirk MT_QUIRK_VALID_IS_CONFIDENCE it is using is not working very
properly. This quirk is originally designed for some WIn7 touchscreens. Use
of this for a Win8 Precision Touchpad will cause unexpected pointer jumping
problem.
Cc: stable@vger.kernel.org # v4.5+
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Andy Lutomirski <luto@kernel.org> # XPS 13 9350, BIOS 1.4.3
Signed-off-by: Allen Hung <allen_hung@dell.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The comments for the unlocked v4l2_ctrl_s_ctrl* functions were wrong (copy
and pasted from the locked variants). Fix this, since it is confusing.
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Memory allocated for maxiradio device is not deallocated when
the device is removed.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
If *nplanes is not zero, it should use the requested size if valid
Signed-off-by: Helen Koike <helen.koike@collabora.co.uk>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
The dv_timings_cap() and enum_dv_timings() pad operations take a pad
number as an input argument and return the DV timings capabilities and
list of supported DV timings for that pad.
Commit bd3e275f3e ("[media] media: i2c: adv7604: Use v4l2-dv-timings
helpers") broke this as it started ignoring the pad number, always
returning the information associated with the currently selected input.
Fix it.
Fixes: bd3e275f3e ("[media] media: i2c: adv7604: Use v4l2-dv-timings helpers")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This patch adds V4L2 controls for Auto Exposure Control and Auto Gain
Control settings. These settings include low pass filter, update
frequency of these settings and the update interval for those units.
[Avoid forward declarations]
[Fix 80 columns limit violation]
[Rename controls to avoid underscores in names]
[Fix the AEC maximum shutter width on MT9V032]
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
The power_on function of the driver resets the chip and sets the
CHIP_CONTROL register to 0. This switches the operating mode to slave.
The s_stream function sets the correct mode. But this caused problems on
a board where the camera chip is operated as master. The camera started
after a random amount of time streaming an image, I observed between 10
and 300 seconds.
The STRFM_OUT and STLN_OUT pins are not connected on this board which
may cause some issues in slave mode. I could not find any documentation
about this.
Keeping the chip in master mode after the reset helped to fix this
issue for me.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Since commit b42261078a ("regmap: i2c: fallback to SMBus if the adapter
does not support standard I2C"), regmap-i2c will check the
I2C_FUNC_SMBUS_[BYTE|WORD]_DATA functionality based on the regmap_config
setting if the adapter does not support standard I2C.
So remove the I2C_FUNC_SMBUS_WORD_DATA functionality check in the driver code.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
If the driver fails to reset the camera or to set up control handlers, it
has to power the camera back off.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This v4l2_subdev_internal_ops structure is never modified. All other
v4l2_subdev_internal_ops structures are declared as const.
Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
The value is not used after the assignment.
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Users won't know what to put in this module option if it isn't
described.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Audio hw params are shared across all DMA channels,
so if the user changes any of these while any DMA channel is
enabled, it will impact the enabled channels, potentially causing
serious instability issues.
This commit avoids such situation, by preventing any hw param
change (on any DMA channel) if any other DMA audio channel is capturing.
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Currently, the driver has a fixed period size of 4096 bytes
(2048 frames). Since this hardware can configure the audio
capture size, this commit allows a period size range of [512-4096].
This is very useful to reduce the audio latency.
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Now that we've introduced the dma_mode parameter to pick the
DMA operation, let's use it to also select the audio DMA
operation.
When dma_mode != memcpy, the driver will avoid using memcpy
in the audio capture path, and the DMA hardware operation
will act directly on the ALSA buffers.
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Now that the driver has the infrastructure to support more
DMA modes, let's add the DMA scatter-gather mode.
In this mode, the device delivers sequential top-bottom
frames. The scatter-gather logic is based on staging's
tw686x-kh driver (by Krzysztof Ha?asa).
Tested-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Now that the driver has the infrastructure to support more
DMA modes, let's add the DMA contiguous interlaced frame mode.
In this mode, the DMA P and B buffers are programmed with
the user-provided buffers. When a P (or B) frame is ready,
a new buffer is dequeued into P (or B).
In addition to interlaced fields, the device can also be
programmed to deliver alternate fields. Only interlaced
mode is supported for now.
Tested-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
When calling eeh_rmv_device() in eeh_reset_device() for partial hotplug
case, @rmv_data instead of its address is the proper argument.
Otherwise, the stack frame is corrupted when writing to
@rmv_data (actually its address) in eeh_rmv_device(). It results in
kernel crash as observed.
This fixes the issue by passing @rmv_data, not its address to
eeh_rmv_device() in eeh_reset_device().
Fixes: 67086e32b5 ("powerpc/eeh: powerpc/eeh: Support error recovery for VF PE")
Reported-by: Pridhiviraj Paidipeddi <ppaidipe@in.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Let's set the corner stone to support all the DMA modes
available on this device.
For stability reasons, the driver is currently setting DMA frame
mode, and using single DMA buffers to get the P and B buffers.
Each frame is then memcpy'ed into the user buffer.
However, other platforms might be interested in avoiding this
memcpy, or in taking advantage of the chip's DMA scatter-gather
capabilities.
To achieve this, this commit introduces a "dma_mode" module parameter,
and a tw686x_dma_ops struct. This will allow to define functions to
alloc/free DMA buffers, and to return the frames to userspace.
The memcpy-based method described above is named as dma_mode="memcpy".
Current alloc/free functions are renamed as tw686x_memcpy_xxx,
and are now used through a memcpy_dma_ops.
Tested-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
If a user space program (e.g., wpa_supplicant) deletes a STA entry that
is currently in NL80211_PLINK_ESTAB state, the number of established
plinks counter was not decremented and this could result in rejecting
new plink establishment before really hitting the real maximum plink
limit. For !user_mpm case, this decrementation is handled by
mesh_plink_deactive().
Fix this by decrementing estab_plinks on STA deletion
(mesh_sta_cleanup() gets called from there) so that the counter has a
correct value and the Beacon frame advertisement in Mesh Configuration
element shows the proper value for capability to accept additional
peers.
Cc: stable@vger.kernel.org
Signed-off-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Commit 311c7c71c9 ("net/mlx5e: Allocate DMA coherent memory on
reader NUMA node") introduced mlx5_*_alloc_node() but missed changing
some calling and warn messages. This patch introduces 2 changes:
* Use mlx5_buf_alloc_node() instead of mlx5_buf_alloc() in
mlx5_wq_ll_create()
* Update the failure warn messages with _node postfix for
mlx5_*_alloc function names
Fixes: 311c7c71c9 ("net/mlx5e: Allocate DMA coherent memory on reader NUMA node")
Signed-off-by: Wang Sheng-Hui <shhuiw@foxmail.com>
Acked-By: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Florian Fainelli says:
====================
net: bgmac: Random fixes
This patch series fixes a few issues spotted by code inspection and
actual testing.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
bgmac_open() calls phy_start() to initialize the PHY state machine,
which will set the interface's carrier state accordingly, no need to
force that as this could be conflicting with the PHY state determined by
PHYLIB.
Fixes: dd4544f054 ("bgmac: driver for GBit MAC core on BCMA bus")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The driver does not start the transmit queue in bgmac_open(). If the
queue was stopped prior to closing then re-opening the interface, we
would never be able to wake-up again.
Fixes: dd4544f054 ("bgmac: driver for GBit MAC core on BCMA bus")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We are checking for the Start of Frame bit in the ctl1 word, while this
bit is set in the ctl0 word instead. Read the ctl0 word and update the
check to verify that.
Fixes: 9cde94506e ("bgmac: implement scatter/gather support")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 7bb11dc9f5 ("bonding: unify all places where
actor-oper key needs to be updated."), the logic in bonding to handle
selection between multiple aggregators has not functioned.
This affects only configurations wherein the bonding slaves
connect to two discrete aggregators (e.g., two independent switches, each
with LACP enabled), thus creating two separate aggregation groups within a
single bond.
The cause is a change in 7bb11dc9f5 to no longer set
AD_PORT_BEGIN on a port after a link state change, which would cause the
port to be reselected for attachment to an aggregator as if were newly
added to the bond. We cannot restore the prior behavior, as it
contradicts IEEE 802.1AX 5.4.12, which requires ports that "become
inoperable" (lose carrier, setting port_enabled=false as per 802.1AX
5.4.7) to remain selected (i.e., assigned to the aggregator). As the port
now remains selected, the aggregator selection logic is not invoked.
A side effect of this change is that aggregators in bonding will
now contain ports that are link down. The aggregator selection logic
does not currently handle this situation correctly, causing incorrect
aggregator selection.
This patch makes two changes to repair the aggregator selection
logic in bonding to function as documented and within the confines of the
standard:
First, the aggregator selection and related logic now utilizes the
number of active ports per aggregator, not the number of selected ports
(as some selected ports may be down). The ad_select "bandwidth" and
"count" options only consider ports that are link up.
Second, on any carrier state change of any slave, the aggregator
selection logic is explicitly called to insure the correct aggregator is
active.
Reported-by: Veli-Matti Lintu <veli-matti.lintu@opinsys.fi>
Fixes: 7bb11dc9f5 ("bonding: unify all places where actor-oper key needs to be updated.")
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes wrong-interface signaling on 32-bit platforms for entries
created when jiffies > 2^31 + MFC_ASSERT_THRESH.
Signed-off-by: Tom Goff <thomas.goff@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
The test_fp_ctl function is used to test if a given value is a valid
floating-point control. The inline assembly in test_fp_ctl uses an
incorrect constraint for the 'orig_fpc' variable. If the compiler
chooses the same register for 'fpc' and 'orig_fpc' the test_fp_ctl()
function always returns true. This allows user space to trigger
kernel oopses with invalid floating-point control values on the
signal stack.
This problem has been introduced with git commit 4725c86055
"s390: fix save and restore of the floating-point-control register"
Cc: stable@vger.kernel.org # v3.13+
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This reverts commit 852ffd0f4e.
There are use cases where an intermediate boot kernel (1) uses kexec
to boot the final production kernel (2). For this scenario we should
provide the original boot information to the production kernel (2).
Therefore clearing the boot information during kexec() should not
be done.
Cc: stable@vger.kernel.org # v3.17+
Reported-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If CONFIG_ARC_DW2_UNWIND is disabled every time arc_unwind_core()
gets called following message gets printed in debug console:
----------------->8---------------
CONFIG_ARC_DW2_UNWIND needs to be enabled
----------------->8---------------
That message makes sense if user indeed wants to see a backtrace or
get nice function call-graphs in perf but what if user disabled
unwinder for the purpose? Why pollute his debug console?
So instead we'll warn user about possibly missing feature once and
let him decide if that was what he or she really wanted.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
With recent binutils update to support dwarf CFI pseudo-ops in gas, we
now get .eh_frame vs. .debug_frame. Although the call frame info is
exactly the same in both, the CIE differs, which the current kernel
unwinder can't cope with.
This broke both the kernel unwinder as well as loadable modules (latter
because of a new unhandled relo R_ARC_32_PCREL from .rela.eh_frame in
the module loader)
The ideal solution would be to switch unwinder to .eh_frame.
For now however we can make do by just ensureing .debug_frame is
generated by removing -fasynchronous-unwind-tables
.eh_frame generated with -gdwarf-2 -fasynchronous-unwind-tables
.debug_frame generated with -gdwarf-2
Fixes STAR 9001058196
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Pull input fixes from Dmitry Torokhov.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: vmmouse - remove port reservation
Input: elantech - add more IC body types to the list
Input: wacom_w8001 - ignore invalid pen data packets
Input: wacom_w8001 - w8001_MAX_LENGTH should be 13
Input: xpad - fix oops when attaching an unknown Xbox One gamepad
MAINTAINERS: add Pali Rohár as reviewer of ALPS PS/2 touchpad driver
Input: add HDMI CEC specific keycodes
Input: add BUS_CEC type
Input: xpad - fix rumble on Xbox One controllers with 2015 firmware
CPU notifications from the firmware coming in when cpufreq is
suspended cause cpufreq_update_current_freq() to return 0 which
triggers the WARN_ON() in cpufreq_update_policy() for no reason.
Avoid that by checking cpufreq_suspended before calling
cpufreq_update_current_freq().
Fixes: c9d9c929e6 (cpufreq: Abort cpufreq_update_current_freq() for cpufreq_suspended set)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.6+ <stable@vger.kernel.org> # 4.6+
If of_match_node() fails, this init function bails out without
calling of_node_put().
Also change of_node_put(of_root) to of_node_put(np); both of them
hold the same pointer, but it seems better to call of_node_put()
against the node returned by of_find_node_by_path().
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_pstate_set_policy() is invoked by the cpufreq core during
driver initialization, on changes of policy attributes (minimim and
maximum frequency, for example) via sysfs and via CPU notifications
from the platform firmware. On some platforms the latter may occur
relatively often.
Commit bb6ab52f2b (intel_pstate: Do not set utilization update hook
too early) made intel_pstate_set_policy() clear the CPU's utilization
update hook before updating the policy attributes for it (and set the
hook again after doind that), but that involves invoking
synchronize_sched() and adds overhead to the CPU notifications
mentioned above and to the sched-RCU handling in general.
That extra overhead is arguably not necessary, because updating
policy attributes when the CPU's utilization update hook is active
should not lead to any adverse effects, so drop the clearing of
the hook from intel_pstate_set_policy() and make it check if
the hook has been set already when attempting to set it.
Fixes: bb6ab52f2b (intel_pstate: Do not set utilization update hook too early)
Reported-by: Jisheng Zhang <jszhang@marvell.com>
Tested-by: Jisheng Zhang <jszhang@marvell.com>
Tested-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
