Commit Graph

117 Commits

Author SHA1 Message Date
Joe Hattori
c65b229699 spmi: hisi-spmi-controller: Drop duplicated OF node assignment in spmi_controller_probe()
spmi_controller_probe() assigns a parent device and an OF node to an
SPMI controller. However, the operations are not needed as they are
already assigned in spmi_controller_alloc(). Thus, remove the duplicated
assignments. An unnecessary OF node reference acquisition is also
dropped by this patch.

Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20250116044907.2947218-1-joe@pf.is.s.u-tokyo.ac.jp
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20250116235339.300485-3-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17 12:58:49 +01:00
Saravana Kannan
bc32bbd040 spmi: Set fwnode for spmi devices
This allows fw_devlink to do proper dependency tracking for SPMI
devices. So, better deferred probe handling, async probing, async
suspend/resume, etc.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20241115230509.1793191-1-saravanak@google.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20250116235339.300485-2-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17 12:58:49 +01:00
Linus Torvalds
e70140ba0d Get rid of 'remove_new' relic from platform driver struct
The continual trickle of small conversion patches is grating on me, and
is really not helping.  Just get rid of the 'remove_new' member
function, which is just an alias for the plain 'remove', and had a
comment to that effect:

  /*
   * .remove_new() is a relic from a prototype conversion of .remove().
   * New drivers are supposed to implement .remove(). Once all drivers are
   * converted to not use .remove_new any more, it will be dropped.
   */

This was just a tree-wide 'sed' script that replaced '.remove_new' with
'.remove', with some care taken to turn a subsequent tab into two tabs
to make things line up.

I did do some minimal manual whitespace adjustment for places that used
spaces to line things up.

Then I just removed the old (sic) .remove_new member function, and this
is the end result.  No more unnecessary conversion noise.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-01 15:12:43 -08:00
Javier Carrasco
77adf4b1f3 spmi: pmic-arb: fix return path in for_each_available_child_of_node()
This loop requires explicit calls to of_node_put() upon early exits
(break, goto, return) to decrement the child refcounter and avoid memory
leaks if the child is not required out of the loop.

A more robust solution is using the scoped variant of the macro, which
automatically calls of_node_put() when the child goes out of scope.

Cc: stable@vger.kernel.org
Fixes: 9799873717 ("spmi: pmic-arb: Add multi bus support")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20241001-spmi-pmic-arb-scoped-v1-1-5872bab34ed6@gmail.com
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20241109002829.160973-2-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-10 10:56:46 +01:00
David Collins
ffcf2eb4bf spmi: pmic-arb: add missing newline in dev_err format strings
dev_err() format strings should end with '\n'.  Several such
format strings in the spmi-pmic-arb driver are missing it.
Add newlines where needed.

Fixes: 02922ccbb3 ("spmi: pmic-arb: Register controller for bus instead of arbiter")
Signed-off-by: David Collins <quic_collinsd@quicinc.com>
Link: https://lore.kernel.org/r/20240703221248.3640490-1-quic_collinsd@quicinc.com
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240725164636.3362690-4-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31 13:49:28 +02:00
Konrad Dybcio
f38ba5459c spmi: pmic-arb: Pass the correct of_node to irq_domain_add_tree
Currently, irqchips for all of the subnodes (which represent a given
bus master) point to the parent wrapper node. This is no bueno, as
no interrupts arrive, ever (because nothing references that node).

Fix that by passing a reference to the respective master's of_node.

Worth noting, this is a NOP for devices with only a single master
described.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240522-topic-spmi_multi_master_irqfix-v2-1-7ec92a862b9f@linaro.org
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Fixes: 02922ccbb3 ("spmi: pmic-arb: Register controller for bus instead of arbiter")
Cc: stable@vger.kernel.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20240725164636.3362690-3-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31 13:49:28 +02:00
Linus Torvalds
c2a96b7f18 Merge tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
 "Here is the big set of driver core changes for 6.11-rc1.

  Lots of stuff in here, with not a huge diffstat, but apis are evolving
  which required lots of files to be touched. Highlights of the changes
  in here are:

   - platform remove callback api final fixups (Uwe took many releases
     to get here, finally!)

   - Rust bindings for basic firmware apis and initial driver-core
     interactions.

     It's not all that useful for a "write a whole driver in rust" type
     of thing, but the firmware bindings do help out the phy rust
     drivers, and the driver core bindings give a solid base on which
     others can start their work.

     There is still a long way to go here before we have a multitude of
     rust drivers being added, but it's a great first step.

   - driver core const api changes.

     This reached across all bus types, and there are some fix-ups for
     some not-common bus types that linux-next and 0-day testing shook
     out.

     This work is being done to help make the rust bindings more safe,
     as well as the C code, moving toward the end-goal of allowing us to
     put driver structures into read-only memory. We aren't there yet,
     but are getting closer.

   - minor devres cleanups and fixes found by code inspection

   - arch_topology minor changes

   - other minor driver core cleanups

  All of these have been in linux-next for a very long time with no
  reported problems"

* tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
  ARM: sa1100: make match function take a const pointer
  sysfs/cpu: Make crash_hotplug attribute world-readable
  dio: Have dio_bus_match() callback take a const *
  zorro: make match function take a const pointer
  driver core: module: make module_[add|remove]_driver take a const *
  driver core: make driver_find_device() take a const *
  driver core: make driver_[create|remove]_file take a const *
  firmware_loader: fix soundness issue in `request_internal`
  firmware_loader: annotate doctests as `no_run`
  devres: Correct code style for functions that return a pointer type
  devres: Initialize an uninitialized struct member
  devres: Fix memory leakage caused by driver API devm_free_percpu()
  devres: Fix devm_krealloc() wasting memory
  driver core: platform: Switch to use kmemdup_array()
  driver core: have match() callback in struct bus_type take a const *
  MAINTAINERS: add Rust device abstractions to DRIVER CORE
  device: rust: improve safety comments
  MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer
  MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER
  firmware: rust: improve safety comments
  ...
2024-07-25 10:42:22 -07:00
Jeff Johnson
5919d93fbe spmi: add missing MODULE_DESCRIPTION() macros
make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/spmi/hisi-spmi-controller.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/spmi/spmi-pmic-arb.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240609-md-drivers-spmi-v1-1-f1d5b24e7a66@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-12 10:44:53 +02:00
Greg Kroah-Hartman
d69d804845 driver core: have match() callback in struct bus_type take a const *
In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *.  This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.

Because the match() callback is in all busses, all busses are modified
to handle this properly.  This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.

For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Alex Elder <elder@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-03 15:16:54 +02:00
Abel Vesa
9799873717 spmi: pmic-arb: Add multi bus support
Starting with HW version 7, there are actually two separate buses
(with two separate sets of wires). So add support for the second bus.
The first platform that needs this support for the second bus is the
Qualcomm X1 Elite, so add the compatible for it as well.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20240417-spmi-multi-master-support-v10-7-5bc6d322e266@linaro.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240507210809.3479953-13-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-08 19:46:11 +01:00
Abel Vesa
02922ccbb3 spmi: pmic-arb: Register controller for bus instead of arbiter
Introduce the bus object in order to decouple the resources
that are bus specific from the arbiter. This way the SPMI controller
is registered with the generic framework at a bus level rather than
arbiter. This is needed in order to prepare for multi bus support.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20240417-spmi-multi-master-support-v10-6-5bc6d322e266@linaro.org
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/53c31752-c8a2-4098-837e-2f84f03c8748@moroto.mountain
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240507210809.3479953-12-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-08 19:46:11 +01:00
Abel Vesa
994ac434b7 spmi: pmic-arb: Make core resources acquiring a version operation
Rather than setting up the core, obsrv and chnls in probe by using
version specific conditionals, add a dedicated "get_core_resources"
version specific op and move the acquiring in there. Since there are
no current users of the second bus yet, drop the comment about why
devm_platform_ioremap_resource can't be used in case of "core",
as it is not applicable anymore.
Don't switch to devm_platform_ioremap_resource though as we need
to keep track of core size.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20240417-spmi-multi-master-support-v10-5-5bc6d322e266@linaro.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240507210809.3479953-11-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-08 19:46:10 +01:00
Abel Vesa
8bc03763e1 spmi: pmic-arb: Make the APID init a version operation
Rather than using conditionals in probe function, add the APID init
as a version specific operation. Due to v7, which supports multiple
buses, pass on the bus index to be used for sorting out the apid base
and count.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20240417-spmi-multi-master-support-v10-4-5bc6d322e266@linaro.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240507210809.3479953-10-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-08 19:46:10 +01:00
Abel Vesa
83bfd7a81f spmi: pmic-arb: Fix some compile warnings about members not being described
Fix the following compile warnings:

 warning: Function parameter or struct member 'core' not described in 'spmi_pmic_arb'
 warning: Function parameter or struct member 'core_size' not described in 'spmi_pmic_arb'
 warning: Function parameter or struct member 'mapping_table_valid' not described in 'spmi_pmic_arb'
 warning: Function parameter or struct member 'pmic_arb' not described in 'pmic_arb_read_data'
 warning: Function parameter or struct member 'pmic_arb' not described in 'pmic_arb_write_data'

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20240417-spmi-multi-master-support-v10-3-5bc6d322e266@linaro.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240507210809.3479953-9-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-08 19:46:10 +01:00
Markus Elfring
c86f90e30a spmi: pmic-arb: Replace three IS_ERR() calls by null pointer checks in spmi_pmic_arb_probe()
The devm_ioremap() function does not return error pointers.
It returns NULL on error.
This issue was detected once more also by using the Coccinelle software.

Update three checks (and corresponding error codes) for failed
function calls accordingly.

Fixes: ffdfbafdc4 ("spmi: Use devm_spmi_controller_alloc()")
Fixes: 231601cd22 ("spmi: pmic-arb: Add support for PMIC v7")
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Link: https://lore.kernel.org/r/82a0768e-95b0-4091-bdd1-14c3e893726b@web.de
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: David Collins <quic_collinsd@quicinc.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240507210809.3479953-6-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-08 19:46:10 +01:00
Vamshi Gajjela
eda4923d78 spmi: hisi-spmi-controller: Do not override device identifier
'nr' member of struct spmi_controller, which serves as an identifier
for the controller/bus. This value is a dynamic ID assigned in
spmi_controller_alloc, and overriding it from the driver results in an
ida_free error "ida_free called for id=xx which is not allocated".

Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com>
Fixes: 70f59c90c8 ("staging: spmi: add Hikey 970 SPMI controller driver")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240228185116.1269-1-vamshigajjela@google.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240507210809.3479953-5-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-08 19:46:10 +01:00
Ricardo B. Marliere
b928d35757 spmi: make spmi_bus_type const
Now that the driver core can properly handle constant struct bus_type,
move the spmi_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240204-bus_cleanup-spmi-v1-1-ef7f278f1987@marliere.net
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240507210809.3479953-2-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-08 19:46:10 +01:00
Sen Chu
c49739235c spmi: mediatek: add device id check
Add device id check for spmi write API.

Signed-off-by: Sen Chu <sen.chu@mediatek.com>
Link: https://lore.kernel.org/r/20230518040729.8789-1-sen.chu@mediatek.com
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-9-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 17:27:04 +01:00
Fei Shao
3ae3cf418a spmi: Return meaningful errors in spmi_controller_alloc()
spmi_controller_alloc() currently returns NULL to all types of errors,
which can be improved.

Use appropriate error code in returns and pass the errors from used
functions where possible.

Signed-off-by: Fei Shao <fshao@chromium.org>
Link: https://lore.kernel.org/r/20230824104101.4083400-6-fshao@chromium.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-8-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 17:27:04 +01:00
Fei Shao
490d88ef54 spmi: hisi-spmi-controller: Use devm_spmi_controller_add()
Convert to the device-managed version of spmi_controller_add() and
delete the unnecessary driver remove callback.

Signed-off-by: Fei Shao <fshao@chromium.org>
Link: https://lore.kernel.org/r/20230824104101.4083400-5-fshao@chromium.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-7-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 17:27:04 +01:00
Fei Shao
f3e67fc406 spmi: mtk-pmif: Reorder driver remove sequence
This driver enables clocks and then adds SPMI controller in probing, so
we expect the reversed sequence in removal.
Fix the order in the remove callback.

Signed-off-by: Fei Shao <fshao@chromium.org>
Link: https://lore.kernel.org/r/20230824104101.4083400-4-fshao@chromium.org
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-6-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 17:27:04 +01:00
Fei Shao
ffdfbafdc4 spmi: Use devm_spmi_controller_alloc()
Convert to the device-managed version of spmi_controller_alloc() and
simplify the excess error handling code.

Signed-off-by: Fei Shao <fshao@chromium.org>
Link: https://lore.kernel.org/r/20230824104101.4083400-3-fshao@chromium.org
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-5-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 17:27:04 +01:00
Fei Shao
b6e53731e0 spmi: Introduce device-managed functions
Utilize the managed resource (devres) framework and add the following
devm_* helpers for the SPMI driver:

- devm_spmi_controller_alloc()
- devm_spmi_controller_add()

[sboyd@kernel.org: Rename to spmi-devres for module niceness, slap on
GPL module license]

Signed-off-by: Fei Shao <fshao@chromium.org>
Link: https://lore.kernel.org/r/20230824104101.4083400-2-fshao@chromium.org
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-4-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 17:27:04 +01:00
Yu-Che Cheng
e821d50ab5 spmi: mediatek: Fix UAF on device remove
The pmif driver data that contains the clocks is allocated along with
spmi_controller.
On device remove, spmi_controller will be freed first, and then devres
, including the clocks, will be cleanup.
This leads to UAF because putting the clocks will access the clocks in
the pmif driver data, which is already freed along with spmi_controller.

This can be reproduced by enabling DEBUG_TEST_DRIVER_REMOVE and
building the kernel with KASAN.

Fix the UAF issue by using unmanaged clk_bulk_get() and putting the
clocks before freeing spmi_controller.

Reported-by: Fei Shao <fshao@chromium.org>
Signed-off-by: Yu-Che Cheng <giver@chromium.org>
Link: https://lore.kernel.org/r/20230717173934.1.If004a6e055a189c7f2d0724fa814422c26789839@changeid
Tested-by: Fei Shao <fshao@chromium.org>
Reviewed-by: Fei Shao <fshao@chromium.org>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-3-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 17:27:04 +01:00
Nícolas F. R. A. Prado
f200fff8d0 spmi: mtk-pmif: Serialize PMIF status check and command submission
Before writing the read or write command to the SPMI arbiter through the
PMIF interface, the current status of the channel is checked to ensure
it is idle. However, since the status only changes from idle when the
command is written, it is possible for two concurrent calls to determine
that the channel is idle and simultaneously send their commands. At this
point the PMIF interface hangs, with the status register no longer being
updated, and thus causing all subsequent operations to time out.

This was observed on the mt8195-cherry-tomato-r2 machine, particularly
after commit 46600ab142 ("regulator: Set PROBE_PREFER_ASYNCHRONOUS for
drivers between 5.10 and 5.15") was applied, since then the two MT6315
devices present on the SPMI bus would probe assynchronously and
sometimes (during probe or at a later point) read the bus
simultaneously, breaking the PMIF interface and consequently slowing
down the whole system.

To fix the issue at its root cause, introduce locking around the channel
status check and the command write, so that both become an atomic
operation, preventing race conditions between two (or more) SPMI bus
read/write operations. A spinlock is used since this is a fast bus, as
indicated by the usage of the atomic variant of readl_poll, and
'.fast_io = true' being used in the mt6315 driver, so spinlocks are
already used for the regmap access.

Fixes: b45b3ccef8 ("spmi: mediatek: Add support for MT6873/8192")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20230724154739.493724-1-nfraprado@collabora.com
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231206231733.4031901-2-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 17:27:04 +01:00