Since commit 52d2253469 ("HID: Make lowlevel driver structs const")
the lowlevel HID drivers are only exposed as const.
Take advantage of this to constify the underlying structure, too.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230130-hid-const-ll-driver-v1-9-3fc282b3b1d0@weissschuh.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Since commit 52d2253469 ("HID: Make lowlevel driver structs const")
the lowlevel HID drivers are only exposed as const.
Take advantage of this to constify the underlying structure, too.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230130-hid-const-ll-driver-v1-7-3fc282b3b1d0@weissschuh.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Since commit 52d2253469 ("HID: Make lowlevel driver structs const")
the lowlevel HID drivers are only exposed as const.
Take advantage of this to constify the underlying structure, too.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230130-hid-const-ll-driver-v1-6-3fc282b3b1d0@weissschuh.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Since commit 52d2253469 ("HID: Make lowlevel driver structs const")
the lowlevel HID drivers are only exposed as const.
Take advantage of this to constify the underlying structure, too.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230130-hid-const-ll-driver-v1-5-3fc282b3b1d0@weissschuh.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Since commit 52d2253469 ("HID: Make lowlevel driver structs const")
the lowlevel HID drivers are only exposed as const.
Take advantage of this to constify the underlying structure, too.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230130-hid-const-ll-driver-v1-4-3fc282b3b1d0@weissschuh.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Since commit 52d2253469 ("HID: Make lowlevel driver structs const")
the lowlevel HID drivers are only exposed as const.
Take advantage of this to constify the underlying structure, too.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230130-hid-const-ll-driver-v1-3-3fc282b3b1d0@weissschuh.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Since commit 52d2253469 ("HID: Make lowlevel driver structs const")
the lowlevel HID drivers are only exposed as const.
Take advantage of this to constify the underlying structure, too.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230130-hid-const-ll-driver-v1-2-3fc282b3b1d0@weissschuh.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Since commit 52d2253469 ("HID: Make lowlevel driver structs const")
the lowlevel HID drivers are only exposed as const.
Take advantage of this to constify the underlying structure, too.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230130-hid-const-ll-driver-v1-1-3fc282b3b1d0@weissschuh.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
described as "32 Execution Unit (EU) Super SKU" in:
Intel Atom x6000E Series, and Intel Pentium and Celeron N and
J Series Processors for IoT Applications
Datasheet, Volume 1
Document Number: 636112-1.6
Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230206043727.46069-1-jsg@jsg.id.au
If get_ep_from_tid() fails to lookup non-NULL value for ep, ep is
dereferenced later regardless of whether it is empty.
This patch adds a simple sanity check to fix the issue.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 944661dd97 ("RDMA/iw_cxgb4: atomically lookup ep and get a reference")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Link: https://lore.kernel.org/r/20230202184850.29882-1-n.zhandarovich@fintech.ru
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Let L1 and L2 be two spinlocks.
Let T1 be a task holding L1 and blocked on L2. T1, currently, is the top
waiter of L2.
Let T2 be the task holding L2.
Let T3 be a task trying to acquire L1.
The following events will lead to a state in which the wait queue of L2
isn't empty, but no task actually holds the lock.
T1 T2 T3
== == ==
spin_lock(L1)
| raw_spin_lock(L1->wait_lock)
| rtlock_slowlock_locked(L1)
| | task_blocks_on_rt_mutex(L1, T3)
| | | orig_waiter->lock = L1
| | | orig_waiter->task = T3
| | | raw_spin_unlock(L1->wait_lock)
| | | rt_mutex_adjust_prio_chain(T1, L1, L2, orig_waiter, T3)
spin_unlock(L2) | | | |
| rt_mutex_slowunlock(L2) | | | |
| | raw_spin_lock(L2->wait_lock) | | | |
| | wakeup(T1) | | | |
| | raw_spin_unlock(L2->wait_lock) | | | |
| | | | waiter = T1->pi_blocked_on
| | | | waiter == rt_mutex_top_waiter(L2)
| | | | waiter->task == T1
| | | | raw_spin_lock(L2->wait_lock)
| | | | dequeue(L2, waiter)
| | | | update_prio(waiter, T1)
| | | | enqueue(L2, waiter)
| | | | waiter != rt_mutex_top_waiter(L2)
| | | | L2->owner == NULL
| | | | wakeup(T1)
| | | | raw_spin_unlock(L2->wait_lock)
T1 wakes up
T1 != top_waiter(L2)
schedule_rtlock()
If the deadline of T1 is updated before the call to update_prio(), and the
new deadline is greater than the deadline of the second top waiter, then
after the requeue, T1 is no longer the top waiter, and the wrong task is
woken up which will then go back to sleep because it is not the top waiter.
This can be reproduced in PREEMPT_RT with stress-ng:
while true; do
stress-ng --sched deadline --sched-period 1000000000 \
--sched-runtime 800000000 --sched-deadline \
1000000000 --mmapfork 23 -t 20
done
A similar issue was pointed out by Thomas versus the cases where the top
waiter drops out early due to a signal or timeout, which is a general issue
for all regular rtmutex use cases, e.g. futex.
The problematic code is in rt_mutex_adjust_prio_chain():
// Save the top waiter before dequeue/enqueue
prerequeue_top_waiter = rt_mutex_top_waiter(lock);
rt_mutex_dequeue(lock, waiter);
waiter_update_prio(waiter, task);
rt_mutex_enqueue(lock, waiter);
// Lock has no owner?
if (!rt_mutex_owner(lock)) {
// Top waiter changed
----> if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
----> wake_up_state(waiter->task, waiter->wake_state);
This only takes the case into account where @waiter is the new top waiter
due to the requeue operation.
But it fails to handle the case where @waiter is not longer the top
waiter due to the requeue operation.
Ensure that the new top waiter is woken up so in all cases so it can take
over the ownerless lock.
[ tglx: Amend changelog, add Fixes tag ]
Fixes: c014ef69b3 ("locking/rtmutex: Add wake_state to rt_mutex_waiter")
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230117172649.52465-1-wander@redhat.com
Link: https://lore.kernel.org/r/20230202123020.14844-1-wander@redhat.com
Block MR cache debugfs creation for IB representor flow as MR cache shouldn't be used
at all in that mode. As part of this change, add missing debugfs cleanup in error path
too.
This change fixes the following debugfs errors:
bond0: (slave enp8s0f1): Enslaving as a backup interface with an up link
mlx5_core 0000:08:00.0: lag map: port 1:1 port 2:1
mlx5_core 0000:08:00.0: shared_fdb:1 mode:queue_affinity
mlx5_core 0000:08:00.0: Operation mode is single FDB
debugfs: Directory '2' with parent '/' already present!
...
debugfs: Directory '22' with parent '/' already present!
Fixes: 73d09b2fe8 ("RDMA/mlx5: Introduce mlx5r_cache_rb_key")
Signed-off-by: Michael Guralnik <michaelgur@nvidia.com>
Link: https://lore.kernel.org/r/482a78c54acbcfa1742a0e06a452546428900ffa.1675328463.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
* icc-dt
dt-bindings: interconnect: split SC7280 to own schema
dt-bindings: interconnect: split SC8280XP to own schema
dt-bindings: interconnect: split SM8450 to own schema
dt-bindings: interconnect: qcom-bwmon: document SM8550 compatibles
dt-bindings: interconnect: OSM L3: Add SM6350 OSM L3 compatible
dt-bindings: interconnect: Exclude all non msm8939 from snoc-mm
dt-bindings: interconnect: samsung,exynos-bus: allow opp-table
Signed-off-by: Georgi Djakov <djakov@kernel.org>
* icc-sa8775p
dt-bindings: interconnect: qcom: document the interconnects for sa8775p
interconnect: qcom: add a driver for sa8775p
dt-bindings: interconnect: qcom,sa8775p-rpmh: fix a typo
Link: https://lore.kernel.org/r/20230118140825.242544-2-brgl@bgdev.pl
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Commits 2f3724930e ("interconnect: qcom: sc7180: Drop IP0
interconnects") and 2fb251c265 ("interconnect: qcom: sdx55: Drop IP0
interconnects") removed IP0 interconnects (and ipa-virt devices support)
in favour of the RPMH clocks. Follow this example for other platforms
defining IP0 RPMH resource. While we are at it, remove several leftover
from the mentioned patches.
* icc-ip0-migration:
interconnect: qcom: sdx55: drop IP0 remnants
interconnect: qcom: sc7180: drop IP0 remnants
interconnect: move ignore_list out of of_count_icc_providers()
interconnect: qcom: sm8150: Drop IP0 interconnects
interconnect: qcom: sm8250: Drop IP0 interconnects
interconnect: qcom: sc8180x: Drop IP0 interconnects
interconnect: qcom: sc8280xp: Drop IP0 interconnects
dt-bindings: interconnect: qcom: Remove ipa-virt compatibles
dt-bindings: interconnect: qcom: drop IPA_CORE related defines
Link: https://lore.kernel.org/r/20230109002935.244320-1-dmitry.baryshkov@linaro.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Use atomic64_try_cmpxchg() instead of atomic64_cmpxchg() in
__update_gt_cputime(). The x86 CMPXCHG instruction returns success in ZF
flag, so this change saves a compare after cmpxchg() (and related move
instruction in front of cmpxchg()).
Also, atomic64_try_cmpxchg() implicitly assigns old *ptr value to "old"
when cmpxchg() fails. There is no need to re-read the value in the loop.
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230116165337.5810-1-ubizjak@gmail.com
Obj flags for shmem objects is not being set correctly. Fixes in setting
BO_ALLOC_USER flag which applies to shmem objs as well.
v2: Add fixes tag (Tvrtko, Matt A)
Fixes: 13d29c8237 ("drm/i915/ehl: unconditionally flush the pages on acquire")
Cc: <stable@vger.kernel.org> # v5.15+
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
[tursulin: Grouped all tags together.]
Link: https://patchwork.freedesktop.org/patch/msgid/20230203135205.4051149-1-aravind.iddamsetty@intel.com
(cherry picked from commit bca0d1d3ce)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Because eb_composite_fence_create() drops the fence_array reference
after creation of the sync_file, only the sync_file holds a ref to the
fence. But fd_install() makes that reference visable to userspace, so
it must be the last thing we do with the fence.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Fixes: 00dae4d3d3 ("drm/i915: Implement SINGLE_TIMELINE with a syncobj (v4)")
Cc: <stable@vger.kernel.org> # v5.15+
[tursulin: Added stable tag.]
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230203164937.4035503-1-robdclark@gmail.com
(cherry picked from commit 960dafa304)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
After disconnecting damage worker from update logic it's left to fbdev
emulation implementation to have fb_dirty function. Currently intel
fbdev doesn't have it. This is causing problems to features (PSR, FBC,
DRRS) relying on dirty callback.
Implement simple fb_dirty callback to deliver notifications about updates
in fb console.
v4: Add proper Fixes tag and modify commit message
v3: Check damage clip
v2: Improved commit message and added Fixes tag
Fixes: f231af498c ("drm/fb-helper: Disconnect damage worker from update logic")
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230123074437.475103-1-jouni.hogander@intel.com
(cherry picked from commit 1af546c2ce)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Due to a workaround we have to make sure the WM1 watermarks block/lines
values are sensible even when WM1 is disabled. To that end we copy those
values from WM0.
However since we now keep each wm level enabled on a per-plane basis
it doesn't seem necessary to do that copy when we already have an
enabled WM1 on the current plane. That is, we might be in a situation
where another plane can only do WM0 (and thus needs the copy) but
the current plane's WM1 is still perfectly valid (ie. fits into the
current DDB allocation).
Skipping the copy could avoid reprogramming the plane's registers
needlessly in some cases.
Fixes: a301cb0fca ("drm/i915: Keep plane watermarks enabled more aggressively")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230131002127.29305-1-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
(cherry picked from commit c580c2d27a)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
The val is defined as unsigned int type, if(val<0) is redundant, so
delete it.
sound/soc/codecs/idt821034.c:449 idt821034_kctrl_gain_put() warn: unsigned 'val' is never less than zero.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3947
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: Herve Codina <herve.codina@bootlin.com>
Link: https://lore.kernel.org/r/20230206075518.84169-1-jiapeng.chong@linux.alibaba.com
Signed-off-by: Mark Brown <broonie@kernel.org>
cppcheck reports
sound/soc/codecs/aw88395/aw88395_lib.c:789:6: error: Uninitialized variable: cur_scene_id [uninitvar]
if (cur_scene_id == 0) {
^
Passing a garbage value to aw_dev_parse_data_by_sec_type_v1() will cause a crash
when the value is used as an array index. This check assumes cur_scene_id is
initialized to 0, so initialize it to 0.
Fixes: 4345865b00 ("ASoC: codecs: ACF bin parsing and check library file for aw88395")
Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230205015733.1721009-1-trix@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Seems like properties parsing and reading was copy-pasted,
so "everest,interrupt-src" and "everest,interrupt-clk" are saved into
the es8326->jack_pol variable. This might lead to wrong settings
being saved into the reg 57 (ES8326_HP_DET).
Fix this by using proper variables while reading properties.
Signed-off-by: Alexey Firago <a.firago@yadro.com>
Reviewed-by: Yang Yingliang <yangyingliang@huawei.com
Link: https://lore.kernel.org/r/20230204195106.46539-1-a.firago@yadro.com
Signed-off-by: Mark Brown <broonie@kernel.org>
In tas5805m_refresh, we switch pages to update the DSP volume control,
but we need to switch back to page 0 before trying to alter the
soft-mute control. This latter page-switch was missing.
Fixes: ec45268467 ("ASoC: add support for TAS5805M digital amplifier")
Signed-off-by: Daniel Beer <daniel.beer@igorinstitute.com>
Link: https://lore.kernel.org/r/1fea38a71ea6ab0225d19ab28d1fa12828d762d0.1675497326.git.daniel.beer@igorinstitute.com
Signed-off-by: Mark Brown <broonie@kernel.org>
There's some setup we need to do in order to get the DSP initialized,
and this can't be done until a bit-clock is ready. In an earlier version
of this driver, this work was done in a DAPM callback.
The DAPM callback doesn't guarantee that the bit-clock is running, so
the work was moved instead to the trigger callback. Unfortunately this
callback runs in atomic context, and the setup code needs to do I2C
transactions.
Here we use a work_struct to kick off the setup in a thread instead.
Fixes: ec45268467 ("ASoC: add support for TAS5805M digital amplifier")
Signed-off-by: Daniel Beer <daniel.beer@igorinstitute.com>
Link: https://lore.kernel.org/r/85d8ba405cb009a7a3249b556dc8f3bdb1754fdf.1675497326.git.daniel.beer@igorinstitute.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Previous documentation suggested that PL1 power limit is always
enabled. However we now find this not to be the case on some
platforms (such as ATSM). Therefore enable PL1 power limit during hwmon
initialization.
Bspec: 51864
v2: Add Bspec reference (Gwan-gyeong)
v3: Add Fixes tag
Fixes: 99f55efb79 ("drm/i915/hwmon: Power PL1 limit and TDP setting")
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230203155309.1042297-1-ashutosh.dixit@intel.com
Marc Kleine-Budde <mkl@pengutronix.de> says:
several people noticed that on modern CAN controllers with wide bit
timing registers the default SJW of 1 can result in unstable or no
synchronization to the CAN network. See Patch 14/17 for details.
During review of v1 Vincent pointed out that the original code and the
series doesn't always check user provided bit timing parameters,
sometimes silently limits them and the return error values are not
consistent.
This series first cleans up some code in bittiming.c, replacing
open-coded variants by macros or functions (Patches 1, 2).
Patch 3 adds the missing assignment of the effective TQ if the
interface is configured with low level timing parameters.
Patch 4 is another code cleanup.
Patches 5, 6 check the bit timing parameter during interface
registration.
Patch 7 adds a validation of the sample point.
The patches 8-13 convert the error messages from netdev_err() to
NL_SET_ERR_MSG_FMT, factor out the SJW handling from
can_fixup_bittiming(), add checking and error messages for the
individual limits and harmonize the error return values.
Patch 14 changes the default SJW value from 1 to min(Phase Seg1, Phase
Seg2 / 2).
Patch 15 switches can_calc_bittiming() to use the new SJW handling.
Patch 16 converts can_calc_bittiming() to NL_SET_ERR_MSG_FMT().
And patch 16 adds a NL_SET_ERR_MSG_FMT() error message to
can_validate_bitrate().
v1: https://lore.kernel.org/all/20220907103845.3929288-1-mkl@pengutronix.de
Link: https://lore.kernel.org/all/20230202110854.2318594-1-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Replace the netdev_err() by NL_SET_ERR_MSG_FMT() to better inform the
user about the problem. While there, use %u to print unsigned values
and improve error message a bit.
In case of an error, return -EINVAL instead of -EDOM, this corresponds
better to the actual meaning of the error value.
Link: https://lore.kernel.org/all/20230202110854.2318594-17-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
"The (Re-)Synchronization Jump Width (SJW) defines how far a
resynchronization may move the Sample Point inside the limits defined
by the Phase Buffer Segments to compensate for edge phase errors." [1]
In other words, this means that the SJW parameter controls the
tolerance of the CAN controller to frequency errors compared to other
CAN controllers.
If the user space does not provide an SJW parameter, the kernel
chooses a default value of 1. This has proven to be a good default
value for classic CAN controllers, but no longer for modern CAN-FD
controllers.
In the past there were CAN controllers like the sja1000 with a rather
limited range of bit timing parameters. For the standard bit rates
this results in the following bit timing parameters:
| Bit timing parameters for sja1000 with 8.000000 MHz ref clock
| _----+--------------=> tseg1: 1 … 16
| / / _---------=> tseg2: 1 … 8
| | | / _-----=> sjw: 1 … 4
| | | | / _-=> brp: 1 … 64 (inc: 1)
| | | | | /
| nominal | | | | | real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error BTR0 BTR1
| 1000000 125 2 3 2 1 1 1000000 0.0% 75.0% 75.0% 0.0% 0x00 0x14
| 800000 125 3 4 2 1 1 800000 0.0% 80.0% 80.0% 0.0% 0x00 0x16
| 666666 125 4 4 3 1 1 666666 0.0% 80.0% 75.0% 6.2% 0x00 0x27
| 500000 125 6 7 2 1 1 500000 0.0% 87.5% 87.5% 0.0% 0x00 0x1c
| 250000 250 6 7 2 1 2 250000 0.0% 87.5% 87.5% 0.0% 0x01 0x1c
| 125000 500 6 7 2 1 4 125000 0.0% 87.5% 87.5% 0.0% 0x03 0x1c
| 100000 625 6 7 2 1 5 100000 0.0% 87.5% 87.5% 0.0% 0x04 0x1c
| 83333 750 6 7 2 1 6 83333 0.0% 87.5% 87.5% 0.0% 0x05 0x1c
| 50000 1250 6 7 2 1 10 50000 0.0% 87.5% 87.5% 0.0% 0x09 0x1c
| 33333 1875 6 7 2 1 15 33333 0.0% 87.5% 87.5% 0.0% 0x0e 0x1c
| 20000 3125 6 7 2 1 25 20000 0.0% 87.5% 87.5% 0.0% 0x18 0x1c
| 10000 6250 6 7 2 1 50 10000 0.0% 87.5% 87.5% 0.0% 0x31 0x1c
The attentive reader will notice that the SJW is 1 in most cases,
while the Seg2 phase is 2. Both values are given in TQ units, which in
turn is a duration in nanoseconds.
For example the 500 kbit/s configuration:
| nominal real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error BTR0 BTR1
| 500000 125 6 7 2 1 1 500000 0.0% 87.5% 87.5% 0.0% 0x00 0x1c
the TQ is 125ns, the Phase Seg2 is "2" (== 250ns), the SJW is "1" (==
125 ns).
Looking at a more modern CAN controller like a mcp2518fd, it has wider
bit timing registers.
| Bit timing parameters for mcp251xfd with 40.000000 MHz ref clock
| _----+--------------=> tseg1: 2 … 256
| / / _---------=> tseg2: 1 … 128
| | | / _-----=> sjw: 1 … 128
| | | | / _-=> brp: 1 … 256 (inc: 1)
| | | | | /
| nominal | | | | | real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error NBTCFG
| 500000 25 34 35 10 1 1 500000 0.0% 87.5% 87.5% 0.0% 0x00440900
The TQ is 25ns, the Phase Seg 2 is "10" (== 250ns), the SJW is "1" (==
25ns).
Since the kernel chooses a default SJW of 1 regardless of the TQ, this
leads to a much smaller SJW and thus much smaller tolerances to
frequency errors.
To maintain the same oscillator tolerances on controllers with wide
bit timing registers, select a default SJW value of Phase Seg2 / 2
unless Phase Seg 1 is less. This results in the following bit timing
parameters:
| Bit timing parameters for mcp251xfd with 40.000000 MHz ref clock
| _----+--------------=> tseg1: 2 … 256
| / / _---------=> tseg2: 1 … 128
| | | / _-----=> sjw: 1 … 128
| | | | / _-=> brp: 1 … 256 (inc: 1)
| | | | | /
| nominal | | | | | real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error NBTCFG
| 500000 25 34 35 10 5 1 500000 0.0% 87.5% 87.5% 0.0% 0x00440904
The TQ is 25ns, the Phase Seg 2 is "10" (== 250ns), the SJW is "5" (==
125ns). Which is the same as on the sja1000 controller.
[1] http://web.archive.org/http://www.oertel-halle.de/files/cia99paper.pdf
Link: https://lore.kernel.org/all/20230202110854.2318594-15-mkl@pengutronix.de
Cc: Mark Bath <mark@baggywrinkle.co.uk>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
If the user space has supplied an invalid SJW value (greater than the
maximum SJW value), report -EINVAL instead of -ERANGE, this better
matches the actual meaning of the error value.
Additionally report an error message via netlink to the user space.
Link: https://lore.kernel.org/all/20230202110854.2318594-13-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Check each bit timing parameter first individually against their
limits and report a meaningful error message via netlink to the user
space.
In case of an error, return -EINVAL instead of -ERANGE, this
corresponds better to the actual meaning of the error value.
Link: https://lore.kernel.org/all/20230202110854.2318594-12-mkl@pengutronix.de
Suggested-by: Vincent Mailhol <vincent.mailhol@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Factor out the functionality of assigning a SJW default value into
can_sjw_set_default() and the checking the SJW limits into
can_sjw_check().
This functions will be improved and called from a different function
in the following patches.
Link: https://lore.kernel.org/all/20230202110854.2318594-11-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This is a preparation patch.
In order to pass warning/error messages during netlink calls back to
user space, pass the extack struct down the callstack of
can_changelink(), the actual error messages will be added in the
following ptaches.
Link: https://lore.kernel.org/all/20230202110854.2318594-10-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Since commit 51c352bdbc ("netlink: add support for formatted extack
messages") formatted extack messages are supported to inform the user
space or warnings/errors during netlink calls.
Replace the netdev_err() by NL_SET_ERR_MSG_FMT() to better inform the
user about the problem. While there, use %u to print unsigned values
and improve error message a bit.
Link: https://lore.kernel.org/all/20230202110854.2318594-9-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The sample point is a value in tenths of a percent. Meaningful values
are between 0 and 1000. Invalid values are rejected and an error
message is returned to user space via netlink.
Link: https://lore.kernel.org/all/20230202110854.2318594-8-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Implement the function can_bittiming_const_valid() to check the
validity of the specified bit timing constant. Call this function from
register_candev() to check the bit timing constants during the
registration of the CAN interface.
Link: https://lore.kernel.org/all/20230202110854.2318594-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The can_fixup_bittiming() function is used to validate the
user-supplied low-level bit timing parameters and calculate the
bitrate prescaler (brp) from the requested time quanta (tq) and the
CAN clock of the controller.
can_fixup_bittiming() selects the best matching integer bit rate
prescaler, which may result in a different time quantum than the value
specified by the user.
Calculate the resulting time quantum and assign it so that the user
sees the effective time quantum.
Link: https://lore.kernel.org/all/20230202110854.2318594-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Commit 1c47fa6b31 ("can: dev: add a helper function to calculate the
duration of one bit") made the constant CAN_SYNC_SEG available in a
header file.
The magic number 1 in can_fixup_bittiming() represents the width of
the sync segment, replace it by CAN_SYNC_SEG to make the code more
readable.
Link: https://lore.kernel.org/all/20230202110854.2318594-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Commit 1c47fa6b31 ("can: dev: add a helper function to calculate the
duration of one bit") added the helper function can_bit_time().
Replace open coded variants of can_bit_time() by the helper function.
Link: https://lore.kernel.org/all/20230202110854.2318594-2-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
