Dan reported that the kernel test robot found an issue with the TMU code
namely in tb_switch_tmu_change_mode() where we should actually go back
to the previous mode in case of failure instead of just returning back
the error. Fix this by unwinding the configuration as we do with the
other error paths in this function.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202311030814.AXtCk7PO-lkp@intel.com/
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
David reported that cppcheck found following possible copy & paste
error from tmu_mode_init():
tmu.c:385:50: style: Expression is always false because 'else if' condition matches previous condition at line 383. [multiCondition]
And indeed this is a bug. Fix it to use correct index
(TB_SWITCH_TMU_MODE_HIFI_UNI).
Reported-by: David Binderman <dcb314@hotmail.com>
Fixes: d49b4f043d ("thunderbolt: Add support for enhanced uni-directional TMU mode")
Cc: stable@vger.kernel.org
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This includes following Thunderbolt/USB4 changes for the v6.6 merge
window:
- Replace broken mailing list address in the ABI document
- Small improvements.
All these have been in linux-next with no reported issues.
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Merge tag 'thunderbolt-for-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-next
Mika writes:
thunderbolt: Changes for v6.6 merge window
This includes following Thunderbolt/USB4 changes for the v6.6 merge
window:
- Replace broken mailing list address in the ABI document
- Small improvements.
All these have been in linux-next with no reported issues.
* tag 'thunderbolt-for-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt:
Documentation/ABI: thunderbolt: Replace 01.org in contact
thunderbolt: Check Intel vendor ID in tb_switch_get_generation()
thunderbolt: Log a warning if device links are not found
thunderbolt: Set variable tmu_params storage class specifier to static
Previously, on unplug events, the TMU mode was disabled first
followed by the Time Synchronization Handshake, irrespective of
whether the tb_switch_tmu_rate_write() API was successful or not.
However, this caused a problem with Thunderbolt 3 (TBT3)
devices, as the TSPacketInterval bits were always enabled by default,
leading the host router to assume that the device router's TMU was
already enabled and preventing it from initiating the Time
Synchronization Handshake. As a result, TBT3 monitors experienced
display flickering from the second hot plug onwards.
To address this issue, we have modified the code to only disable the
Time Synchronization Handshake during TMU disable if the
tb_switch_tmu_rate_write() function is successful. This ensures that
the TBT3 devices function correctly and eliminates the display
flickering issue.
Co-developed-by: Sanath S <Sanath.S@amd.com>
Signed-off-by: Sanath S <Sanath.S@amd.com>
Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
smatch reports
drivers/thunderbolt/tmu.c:30:3: warning: symbol
'tmu_params' was not declared. Should it be static?
This variable is only used in its defining file so should be static.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This is new TMU mode introduced with the USB4 v2. This mode is simpler
than the existing ones and allows all CL states as well. Enable this for
all links where both side routers are v2 and keep the existing
functionality for the v1 and earlier links.
Currently only support the MedRes rate. We can add the HiFi rate later
too if it turns out to be useful.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
There is really no need to call any of the CLx functions in the TMU code
so remove all these checks. This makes the TMU enable/disable flows
easier to follow as well.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
There really don't belong to switch.c so move them into their own file.
As we do this rename the functions to match the conventions used
elsewhere in the driver.
No functional changes.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This is better to be part of the software connection manager flows in
tb.c. Also name the new function tb_increase_tmu_accuracy() to match
what it actually does.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Now this is split into two with one having a misleading name
(tb_switch_tmu_unidirectional_enable()).
Make this easier to read, rename and consolidate the two functions into
one with name that explains what it actually does. Use the two constants
as well that were added but never used to make it clear which bits are
being set.
No functional changes.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
There is no point passing it as we already have a field for that. While
there clean up the kernel-doc of things that do not really belong to the
API documentation (these can be figured out from the spec itself).
No functional changes.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Drop extra empty line and get rid of the '__' in function names. No
functional changes.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Introduce tb_switch_downstream_port() helper function that returns the
downstream port of a parent switch that is connected to the upstream
port of specified switch. From now on, we use it all across the driver
where applicable.
While there fix a whitespace in comment and rename 'downstream' to
'down' to be consistent with the rest of the driver.
Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Here we configure TMU mode to HiFi uni-directional once DP tunnel
is created. This is due to accuracy requirement for DP tunneling
as appears in CM guide 1.0, section 7.3.2.
Due to Intel hardware limitation, once we changed the TMU mode to HiFi
uni-directional (when DP tunnel exists), we don't change TMU mode back to
normal uni-directional, even if DP tunnel is torn down later.
Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
In this patch we add support for a second low power state of the link: CL1.
Low power states (called collectively CLx) are used to reduce
transmitter and receiver power when a high-speed lane is idle.
We enable it, if both sides of the link support it,
and only for the first hop router (i.e. the first device that connected
to the host router). This is needed for better thermal management.
Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
In case of uni-directional time sync, TMU handshake is
initiated by upstream router. In case of bi-directional
time sync, TMU handshake is initiated by downstream router.
In order to handle correctly the case of uni-directional mode,
we avoid changing the upstream router's rate to off,
because it might have another downstream router plugged that is set to
uni-directional mode (and we don't want to change its mode).
Instead, we always change downstream router's rate.
Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Low power link states (called collectively CLx) are used to reduce
transmitter and receiver power when a high-speed lane is idle. The
simplest one being called CL0s. Follow what we already do for USB4
device routers and enable CL0s for Intel Titan Ridge device router too.
This allows better thermal management.
Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Intel Titan Ridge based routers have slightly different flow for time
disruption than USB4 compliant routers. This makes it work on Titan
Ridge too. Needed to enable link low power states on Titan Ridge.
Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Up until Titan Ridge (Thunderbolt 3) device routers only supported
bi-directional mode. In this patch we add to TMU a uni-directional mode.
The uni-directional mode is needed for enabling of low power state of
the link (CLx).
Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Time Management Unit (TMU) is included in each USB4 router. It is used
to synchronize time across the USB4 fabric. By default when USB4 router
is plugged to the domain, its TMU is turned off. This differs from
Thunderbolt (1, 2 and 3) devices whose TMU is by default configured to
bi-directional HiFi mode. Since time synchronization is needed for
proper Display Port tunneling this means we need to configure the TMU on
USB4 compliant devices.
The USB4 spec allows some flexibility on how the TMU can be configured.
This makes it possible to enable link power management states (CLx) in
certain topologies, where for example DP tunneling is not used. TMU can
also be re-configured dynamicaly depending on types of tunnels created
over the USB4 fabric.
In this patch we simply configure the TMU to be in bi-directional HiFi
mode. This way we can tunnel any kind of traffic without need to perform
complex steps to re-configure the domain dynamically. We can add more
fine-grained TMU configuration later on when we start enabling CLx
states.
Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com>
Co-developed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20191217123345.31850-8-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
