abs_vdebt is an atomic_64 which tracks how much over budget a given cgroup
is and controls the activation of use_delay mechanism. Once a cgroup goes
over budget from forced IOs, it has to pay it back with its future budget.
The progress guarantee on debt paying comes from the iocg being active -
active iocgs are processed by the periodic timer, which ensures that as time
passes the debts dissipate and the iocg returns to normal operation.
However, both iocg activation and vdebt handling are asynchronous and a
sequence like the following may happen.
1. The iocg is in the process of being deactivated by the periodic timer.
2. A bio enters ioc_rqos_throttle(), calls iocg_activate() which returns
without anything because it still sees that the iocg is already active.
3. The iocg is deactivated.
4. The bio from #2 is over budget but needs to be forced. It increases
abs_vdebt and goes over the threshold and enables use_delay.
5. IO control is enabled for the iocg's subtree and now IOs are attributed
to the descendant cgroups and the iocg itself no longer issues IOs.
This leaves the iocg with stuck abs_vdebt - it has debt but inactive and no
further IOs which can activate it. This can end up unduly punishing all the
descendants cgroups.
The usual throttling path has the same issue - the iocg must be active while
throttled to ensure that future event will wake it up - and solves the
problem by synchronizing the throttling path with a spinlock. abs_vdebt
handling is another form of overage handling and shares a lot of
characteristics including the fact that it isn't in the hottest path.
This patch fixes the above and other possible races by strictly
synchronizing abs_vdebt and use_delay handling with iocg->waitq.lock.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Vlad Dmitriev <vvd@fb.com>
Cc: stable@vger.kernel.org # v5.4+
Fixes: e1518f63f2 ("blk-iocost: Don't let merges push vtime into the future")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
- Add a SPDX header;
- Adjust document and section titles;
- Some whitespace fixes and new line breaks;
- Mark literal blocks as such;
- Add table markups;
- Add lists markups;
- Add it to filesystems/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/32332c1659a28c22561cb5e64162c959856066b4.1588021877.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This document has its own style. It seems to be print output
for the old matrixial printers where backspace were used to
do double prints.
For the conversion, I used several regex expressions to get
rid of some weird stuff. The patch also does almost all possible
conversions in order to get a nice output document, while keeping
it readable/editable as is:
- Add a SPDX header;
- Add a document title;
- Adjust document title;
- Adjust section titles;
- Some whitespace fixes and new line breaks;
- Mark literal blocks as such;
- Adjust list markups;
- Mark some unumbered titles with bold font;
- Use footnoote markups;
- Add table markups;
- Use notes markups;
- Add it to filesystems/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/25c06c40c3d7b947a131c3be124ce0e93cc00ae3.1588021877.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
- Add a SPDX header;
- Adjust document and section titles;
- Comment out text ToC for html/pdf output;
- Some whitespace fixes and new line breaks;
- Add table markups;
- Add it to filesystems/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/e33ec382a53cf10ffcbd802f6de3f384159cddba.1588021877.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
- Add a SPDX header;
- Adjust document and section titles;
- Comment out text ToC for html/pdf output;
- Some whitespace fixes and new line breaks;
- Adjust the events list to make them look better for html output;
- Add it to filesystems/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/49026a8ea7e714c2e0f003aa26b975b1025476b7.1588021877.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Add myself as co-maintainer of the Amlogic VDEC driver, and add the
missing vdec DT yaml bindings.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This device uses the SIPODEV SP1064 touchpad, which does not
supply descriptors, so it has to be added to the override list.
Cc: stable@vger.kernel.org
Signed-off-by: Julian Sax <jsbc@gmx.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
flush_icache_range() contains a bodge to avoid issuing IPIs when the kgdb
trap handler is running because issuing IPIs is unsafe (and not needed)
in this execution context. However the current test, based on
kgdb_connected is flawed: it both over-matches and under-matches.
The over match occurs because kgdb_connected is set when gdb attaches
to the stub and remains set during normal running. This is relatively
harmelss because in almost all cases irq_disabled() will be false.
The under match is more serious. When kdb is used instead of kgdb to access
the debugger then kgdb_connected is not set in all the places that the
debug core updates sw breakpoints (and hence flushes the icache). This
can lead to deadlock.
Fix by replacing the ad-hoc check with the proper kgdb macro. This also
allows us to drop the #ifdef wrapper.
Fixes: 3b8c9f1cdf ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings")
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200504170518.2959478-1-daniel.thompson@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
According to latest H/W manual v1.50, the description of channel
number in the VCDT/VCDT2 register is decremented by one.
Therefore, this patch fixes it about comment.
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The function imx_media_init_mbus_fmt() initializes the imx subdevice
mbus colorimetry to some sane defaults when the subdevice is registered.
Currently it guesses at a colorspace based on the passed mbus pixel
format. If the format is RGB, it chooses colorspace V4L2_COLORSPACE_SRGB,
and if the format is YUV, it chooses V4L2_COLORSPACE_SMPTE170M.
While that might be a good guess, it's not necessarily true that a RGB
pixel format encoding uses a SRGB colorspace, or that a YUV encoding
uses a SMPTE170M colorspace. Instead of making this dubious guess,
just default the colorspace to SRGB.
Reported-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
A test with the command below gives for example this error:
arch/arm64/boot/dts/rockchip/rk3328-evb.dt.yaml: video-codec@ff350000:
interrupts: [[0, 9, 4]] is too short
arch/arm64/boot/dts/rockchip/rk3328-evb.dt.yaml: video-codec@ff350000:
interrupt-names: ['vdpu'] is too short
arch/arm64/boot/dts/rockchip/rk3328-evb.dt.yaml: video-codec@ff350000:
interrupt-names:0: 'vepu' was expected
With the conversion of rockchip-vpu.txt to yaml the correct
'interrupt-names' for rk3328 was not included, so add them now.
Also add 'minItems' to 'interrupts'for the completeness.
make ARCH=arm64 dtbs_check
DT_SCHEMA_FILES=Documentation/devicetree/bindings/media/rockchip-vpu.yaml
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
In selfpath, RGB capture formats are received in the sink pad as YUV
and are converted to RGB only when writing to memory. So the validation
function should accept YUV bus formats with RGB capture encoding.
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
RGB formats in selfpath should receive input format as YUV422.
The resizer input format is always YUV422 and therefore
if the capture format is RGB, the resizer should not change
the YUV rations.
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The statement "if (rsz->fmt_type == V4L2_PIXEL_ENC_YUV)"
can be removed since the value of rsz->fmt_type is either
V4L2_PIXEL_ENC_YUV or V4L2_PIXEL_ENC_BAYER and the function
returns if it is bayer. In addition some doc with clarification
is added.
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Currently the format info of the capture is retrieved by calling
the function v4l2_format_info. This is not needed since it is
already saved in the capture object.
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
When multiple instances of the same MHI product are present in a system,
we can see a splat from mhi_create_devices() - "sysfs: cannot create
duplicate filename".
This is because the device names assigned to the MHI channel devices are
non-unique. They consist of the channel's name, and the channel's pipe
id. For identical products, each instance is going to have the same
set of channel (both in name and pipe id).
To fix this, we prepend the device name of the parent device that the
MHI channels belong to. Since different instances of the same product
should have unique device names, this makes the MHI channel devices for
each product also unique.
Additionally, remove the pipe id from the MHI channel device name. This
is an internal detail to the MHI product that provides little value, and
imposes too much device specific internal details to userspace. It is
expected that channel with a specific name (ie "SAHARA") has a specific
client, and it does not matter what pipe id that channel is enumerated on.
The pipe id is an internal detail between the MHI bus, and the hardware.
The client is not expected to make decisions based on the pipe id, and to
do so would require the client to have intimate knowledge of the hardware,
which is inappropiate as it may violate the layering provided by the MHI
bus. The limitation of doing this is that each product may only have one
instance of a channel by a unique name. This limitation is appropriate
given the usecases of MHI channels.
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200430190555.32741-7-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a typo - "runtimet" should be "runtime". Fix it.
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200430190555.32741-6-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When reading or writing MHI registers, the core assumes that the physical
link is a memory mapped PCI link. This assumption may not hold for all
MHI devices. The controller knows what is the physical link (ie PCI, I2C,
SPI, etc), and therefore knows the proper methods to access that link.
The controller can also handle link specific error scenarios, such as
reading -1 when the PCI link went down.
Therefore, it is appropriate that the MHI core requests the controller to
make register accesses on behalf of the core, which abstracts the core
from link specifics, and end up removing an unnecessary assumption.
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200430190555.32741-5-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the MHI core detects invalid data due to a PCI read, it calls into
the controller via link_status() to double check that the link is infact
down. All in all, this is pretty pointless, and racy. There are no good
reasons for this, and only drawbacks.
Its pointless because chances are, the controller is going to do the same
thing to determine if the link is down - attempt a PCI access and compare
the result. This does not make the link status decision any smarter.
Its racy because its possible that the link was down at the time of the
MHI core access, but then recovered before the controller access. In this
case, the controller will indicate the link is not down, and the MHI core
will precede to use a bad value as the MHI core does not attempt to retry
the access.
Retrying the access in the MHI core is a bad idea because again, it is
racy - what if the link is down again? Furthermore, there may be some
higher level state associated with the link status, that is now invalid
because the link went down.
The only reason why the MHI core could see "invalid" data when doing a PCI
access, that is actually valid, is if the register actually contained the
PCI spec defined sentinel for an invalid access. In this case, it is
arguable that the MHI implementation broken, and should be fixed, not
worked around.
Therefore, remove the link_status() callback before anyone attempts to
implement it.
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200430190555.32741-4-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Powerdown is necessary if mhi_sync_power_up fails due to a timeout, to
clean up the resources. Otherwise a BUG could be triggered when
attempting to clean up MSIs because the IRQ is still active from a
request_irq().
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200430190555.32741-3-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the current parsing of mhi_flags, the following statement always
return false:
eob = !!(flags & MHI_EOB);
This is due to the fact that 'enum mhi_flags' starts with index 0 and we
are using direct AND operation to extract each bit. Fix this by using
BIT() macros for defining the flags so that the reset of the code need not
be touched.
Fixes: 189ff97cca ("bus: mhi: core: Add support for data transfer")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200430190555.32741-2-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Disable the MEI driver on LBG SPS (server) platforms, some corner
flows such as recovery mode does not work, and the driver
doesn't have working use cases.
Cc: <stable@vger.kernel.org>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20200428211200.12200-1-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
