SPI is one of the interfaces used to access devices which have a POSIX
clock driver (real time clocks, 1588 timers etc). The fact that the SPI
bus is slow is not what the main problem is, but rather the fact that
drivers don't take a constant amount of time in transferring data over
SPI. When there is a high delay in the readout of time, there will be
uncertainty in the value that has been read out of the peripheral.
When that delay is constant, the uncertainty can at least be
approximated with a certain accuracy which is fine more often than not.
Timing jitter occurs all over in the kernel code, and is mainly caused
by having to let go of the CPU for various reasons such as preemption,
servicing interrupts, going to sleep, etc. Another major reason is CPU
dynamic frequency scaling.
It turns out that the problem of retrieving time from a SPI peripheral
with high accuracy can be solved by the use of "PTP system
timestamping" - a mechanism to correlate the time when the device has
snapshotted its internal time counter with the Linux system time at that
same moment. This is sufficient for having a precise time measurement -
it is not necessary for the whole SPI transfer to be transmitted "as
fast as possible", or "as low-jitter as possible". The system has to be
low-jitter for a very short amount of time to be effective.
This patch introduces a PTP system timestamping mechanism in struct
spi_transfer. This is to be used by SPI device drivers when they need to
know the exact time at which the underlying device's time was
snapshotted. More often than not, SPI peripherals have a very exact
timing for when their SPI-to-interconnect bridge issues a transaction
for snapshotting and reading the time register, and that will be
dependent on when the SPI-to-interconnect bridge figures out that this
is what it should do, aka as soon as it sees byte N of the SPI transfer.
Since spi_device drivers are the ones who'd know best how the peripheral
behaves in this regard, expose a mechanism in spi_transfer which allows
them to specify which word (or word range) from the transfer should be
timestamped.
Add a default implementation of the PTP system timestamping in the SPI
core. This is not going to be satisfactory performance-wise, but should
at least increase the likelihood that SPI device drivers will use PTP
system timestamping in the future.
There are 3 entry points from the core towards the SPI controller
drivers:
- transfer_one: The driver is passed individual spi_transfers to
execute. This is the easiest to timestamp.
- transfer_one_message: The core passes the driver an entire spi_message
(a potential batch of spi_transfers). The core puts the same pre and
post timestamp to all transfers within a message. This is not ideal,
but nothing better can be done by default anyway, since the core has
no insight into how the driver batches the transfers.
- transfer: Like transfer_one_message, but for unqueued drivers (i.e.
the driver implements its own queue scheduling).
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20190905010114.26718-3-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Later versions of the QSPI controller (e.g. in i.MX6UL/ULL and i.MX7)
seem to have an additional TDH setting in the FLSHCR register, that
needs to be set in accordance with the access mode that is used (DDR
or SDR).
Previous bootstages such as BootROM or bootloader might have used the
DDR mode to access the flash. As we currently only use SDR mode, we
need to make sure the TDH bits are cleared upon initialization.
Fixes: 84d043185d ("spi: Add a driver for the Freescale/NXP QuadSPI controller")
Cc: <stable@vger.kernel.org>
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Acked-by: Han Xu <han.xu@nxp.com>
Link: https://lore.kernel.org/r/20191007071933.26786-1-frieder.schrempf@kontron.de
Signed-off-by: Mark Brown <broonie@kernel.org>
There is finally no more users left in the kernel of drmP.h
and drm_os_linux.h (drmP.h was the only user left).
Delete the header files and delete the corresponding todo entry.
When we started this quest there was more than 700 users of drmP.h.
And drmP.h was a huge cover-it-all header file.
Daniel Vetter is the one that followed the work from start
to the end and in between many people have contributed to the
removal process - thanks to everyone!
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Sean Paul <sean@poorly.run>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191007171224.1581-3-sam@ravnborg.org
drmP.h is deprecated and will be deleted.
Replace use with proper header.
Divide header includes in blocks while touching these.
Build tested with various archtectures and configs.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Fixes: ae85b0df12 ("drm_dp_cec: add connector info support.")
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Dariusz Marcinkiewicz <darekm@google.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191007171224.1581-2-sam@ravnborg.org
The sleep flag bit decides the mode for BUCK_MODE_MANUAL case, simplify
the logic as the result is the same.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Link: https://lore.kernel.org/r/20191007115009.25672-2-axel.lin@ingics.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The #mtd channel (on OFTC servers) is being used to discuss MTD related
topics. Add it to the MTD entry.
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
The driver does not use input subsystem so we do not need this header,
and it is being removed, so stop pulling it in.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
We discussed a better location for this file, and agreed that
core-api/ is a good fit. Rename it to symbol-namespaces.rst
for disambiguation, and also add it to index.rst and MAINTAINERS.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
A common bane of ours is arbitrary delays in ksoftirqd processing our
submission tasklet. Give the submission tasklet a kick before we wait to
avoid those delays eating into a tight timeout.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191008105655.13256-1-chris@chris-wilson.co.uk
At some point in time there was the idea that we could have multiple
stream from the same piece of HW but that never materialized and given
the hard time we already have making everything work with the
submission side, there is no real point having this list of 1 element
around.
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191008140111.5437-1-chris@chris-wilson.co.uk
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/staging/comedi/drivers/dt3000.c: In function dt3k_ai_insn_read:
drivers/staging/comedi/drivers/dt3000.c:511:27: warning: variable aref set but not used [-Wunused-but-set-variable]
It is not used since commit 2e310235ca ("staging:
comedi: dt3000: rename dt3k_ai_insn()")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/1570520515-2186-7-git-send-email-zhengbin13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit ad67b74d24 ("printk: hash addresses printed with %p"),
an obfuscated kernel pointer is printed at boot:
vchiq: vchiq_init_state: slot_zero = (____ptrval____)
Remove the the print completely, as it's useless without the address.
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Link: https://lore.kernel.org/r/20191008123346.3931-1-mcroce@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Configure the display Quality of service (QoS) levels priority if the
optional property node "arm,malidp-aqros-value" is defined in DTS file.
QoS signaling using AQROS and AWQOS AXI interface signals, the AQROS is
driven from the "RQOS" register, so needed to program the RQOS register
to avoid the high resolutions flicker issue on the LS1028A platform.
Signed-off-by: Wen He <wen.he_1@nxp.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190910075913.17650-2-wen.he_1@nxp.com
According to
Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt,
i2c-mux-idle-disconnect is a property of a parent node since it
pertains to the mux/switch as a whole, so move it there and drop all
of the concurrences in child nodes.
Fixes: d031773169 ("ARM: dts: Adds device tree file for McGill's IceBoard, based on TI AM3874")
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Benoît Cousson <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Graeme Smecher <gsmecher@threespeedlogic.com>
Cc: linux-omap@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Tested-by: Graeme Smecher <gsmecher@threespeedlogic.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Current implementation for ti-sysc powers down the module once module
init is complete. However, right after power is disabled, it is enabled
via runtime PM. This is unnecessary so avoid it by re-ordering the
events a bit; move powering down of the module post runtime PM enable
which makes sure the use counts are maintained properly and there is
no extra power down/up sequence for the module.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
There seems to be unnecessary extra hardreset line toggling applied
during module init. This is unnecessary, as the reset lines are already
asserted during boot, and it can cause certain modules to hang (iommus,
remoteprocs.) Remove the extra hardreset toggle, and remove the now
redundant function to handle this also.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
The main clocks and reset controls have a hardware level dependency,
where one can't transition state without the other one transitioning.
Because we don't have the dependency implemented in software, we must
ensure the ordering of these two is done properly; they way this is
handled is that clocks transition on software level without delay,
and the status is only polled on reset side. Because of this, we must
re-order the main clock and reset handling on the ti-sysc driver.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
The clkctrl code searches for the parent clockdomain based on the name
of the CM provider node. The introduction of SGX node for omap5 made
the node name for the gpu_cm to be clock-controller. There is no
clockdomain named like this, so the lookup fails. Fix by changing
the node name properly.
Fixes: 394534cb07 ("ARM: dts: Configure sgx for omap5")
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Since the dirtyfb ioctl doesn't give us any hints as to which plane is
scanning out the fb it's marking as damaged, we need to loop through
planes to find it.
Currently we just reach into plane state and check, but that can race
with another commit changing the fb out from under us. This patch locks
the plane before checking the fb and will release the lock if the plane
is not displaying the dirty fb.
Fixes: b9fc5e01d1 ("drm: Add helper to implement legacy dirtyfb")
Cc: Rob Clark <robdclark@gmail.com>
Cc: Deepak Rawat <drawat@vmware.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.0+
Reported-by: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190904202938.110207-1-sean@poorly.run
The number of RESET registers and offset of RESET_LEVEL register for
Meson-A1 are different from previous SoCs, In order to describe these
differences, we introduce the struct meson_reset_param.
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Add DT bindings for the Meson-A1 SoC Reset Controller include file,
and also slightly update documentation.
Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/staging/sm750fb/ddk750_chip.c: In function set_chip_clock:
drivers/staging/sm750fb/ddk750_chip.c:59:15: warning: variable actual_mx_clk set but not used [-Wunused-but-set-variable]
It is not used since commit f0977109a5 ("staging:
sm750fb: lower case to fix camelcase checkpatch warning")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/1570520515-2186-4-git-send-email-zhengbin13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/staging/sm750fb/ddk750_mode.c: In function ddk750_setModeTiming:
drivers/staging/sm750fb/ddk750_mode.c:212:15: warning: variable uiActualPixelClk set but not used [-Wunused-but-set-variable]
It is not used since commit 81dee67e21 ("staging:
sm750fb: add sm750 to staging")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/1570520515-2186-3-git-send-email-zhengbin13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If vchi_msg_dequeue return -1, variable m is not assigined,
need to return.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/1570520515-2186-2-git-send-email-zhengbin13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
snd_soc_rtdcom_lookup() will be removed.
It is used at fsl_dma_isr(), but it is just for dev_err(dev..).
rtd->dev is very enough for it.
This patch replace component->dev to rtd->dev
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/877e5n90cn.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>
When building for a non-Cavium MIPS system with COMPILE_TEST=y, the
Octeon ethernet driver hits a number of issues due to use of macros
provided only for CONFIG_CAVIUM_OCTEON_SOC=y configurations. For
example:
drivers/staging/octeon/ethernet-rx.c:190:6: error:
'CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE' undeclared (first use in this function)
drivers/staging/octeon/ethernet-rx.c:472:25: error:
'OCTEON_IRQ_WORKQ0' undeclared (first use in this function)
These come from various asm/ headers that a non-Octeon build will be
using a non-Octeon version of.
Fix this by using the octeon-stubs.h header for non-Cavium MIPS builds,
and only using the real asm/octeon/ headers when building a Cavium
Octeon kernel configuration.
This requires that octeon-stubs.h doesn't redefine XKPHYS_TO_PHYS, which
is defined for MIPS by asm/addrspace.h which is pulled in by many other
common asm/ headers.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
URL: https://lore.kernel.org/linux-mips/CAMuHMdXvu+BppwzsU9imNWVKea_hoLcRt9N+a29Q-QsjW=ip2g@mail.gmail.com/
Fixes: 171a9bae68 ("staging/octeon: Allow test build on !MIPS")
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Link: https://lore.kernel.org/r/20191007231741.2012860-1-paul.burton@mips.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove typecast in the call to kfree as it is not needed.
Issue found using the below coccinelle script,
@@
type t1;
expression e;
@@
-kfree((t1 *)e);
+kfree(e);
Signed-off-by: Nachammai Karuppiah <nachukannan@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Link: https://lore.kernel.org/r/1570511353-64646-1-git-send-email-nachukannan@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes checkpatch.pl warning: do not add new typedefs in
drivers/staging/octeon/octeon-stubs.h:41
Signed-off-by: Wambui Karuga <wambui.karugax@gmail.com>
Link: https://lore.kernel.org/r/20191008040943.9283-1-wambui.karugax@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
