Sometimes regulator_get() gets called twice for the same supply on the
same device. This may happen e.g. when a framework / library is used
which uses the regulator; and the driver itself also needs to enable
the regulator in some cases where the framework will not enable it.
Commit ff268b56ce8c ("regulator: core: Don't spew backtraces on
duplicate sysfs") already takes care of the backtrace which would
trigger when creating a duplicate consumer symlink under
/sys/class/regulator/regulator.%d in this scenario.
Commit c33d442328f5 ("debugfs: make error message a bit more verbose")
causes a new error to get logged in this scenario:
[ 26.938425] debugfs: Directory 'wm5102-codec-MICVDD' with parent 'spi-WM510204:00-MICVDD' already present!
There is no _nowarn variant of debugfs_create_dir(), but we can detect
and avoid this problem by checking the return value of the earlier
sysfs_create_link_nowarn() call.
Add a check for the earlier sysfs_create_link_nowarn() failing with
-EEXIST and skip the debugfs_create_dir() call in that case, avoiding
this error getting logged.
Fixes: c33d442328f5 ("debugfs: make error message a bit more verbose")
Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20210122183250.370571-1-hdegoede@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Make regulator_sync_voltage() to re-balance voltage state of a coupled regulators instead of changing the voltage directly. Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30 Tested-by: Dmitry Osipenko <digetx@gmail.com> # A500 T20 and Nexus7 T30 Tested-by: Nicolas Chauvet <kwizart@gmail.com> # PAZ00 T20 Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30 Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Link: https://lore.kernel.org/r/20210122174311.28230-1-digetx@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
With commit eaa7995c529b54 (regulator: core: avoid regulator_resolve_supply() race condition) we started holding the rdev lock while resolving supplies, an operation that requires holding the regulator_list_mutex. This results in lockdep warnings since in other places we take the list mutex then the mutex on an individual rdev. Since the goal is to make sure that we don't call set_supply() twice rather than a concern about the cost of resolution pull the rdev lock and check for duplicate resolution down to immediately before we do the set_supply() and drop it again once the allocation is done. Fixes: eaa7995c529b54 (regulator: core: avoid regulator_resolve_supply() race condition) Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210122132042.10306-1-broonie@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
The final step in regulator_register() is to call
regulator_resolve_supply() for each registered regulator
(including the one in the process of being registered). The
regulator_resolve_supply() function first checks if rdev->supply
is NULL, then it performs various steps to try to find the supply.
If successful, rdev->supply is set inside of set_supply().
This procedure can encounter a race condition if two concurrent
tasks call regulator_register() near to each other on separate CPUs
and one of the regulators has rdev->supply_name specified. There
is currently nothing guaranteeing atomicity between the rdev->supply
check and set steps. Thus, both tasks can observe rdev->supply==NULL
in their regulator_resolve_supply() calls. This then results in
both creating a struct regulator for the supply. One ends up
actually stored in rdev->supply and the other is lost (though still
present in the supply's consumer_list).
Here is a kernel log snippet showing the issue:
[ 12.421768] gpu_cc_gx_gdsc: supplied by pm8350_s5_level
[ 12.425854] gpu_cc_gx_gdsc: supplied by pm8350_s5_level
[ 12.429064] debugfs: Directory 'regulator.4-SUPPLY' with parent
'17a00000.rsc:rpmh-regulator-gfxlvl-pm8350_s5_level'
already present!
Avoid this race condition by holding the rdev->mutex lock inside
of regulator_resolve_supply() while checking and setting
rdev->supply.
Signed-off-by: David Collins <collinsd@codeaurora.org>
Link: https://lore.kernel.org/r/1610068562-4410-1-git-send-email-collinsd@codeaurora.org
Signed-off-by: Mark Brown <broonie@kernel.org>
The function regulator_set_device_supply() is referenced a few times in
comments in regulator/core.c; however this function was removed a long
time ago by commit a5766f11cfd3 ("regulator: core - Rework machine API to
remove string based functions."). Update those references to point to
set_consumer_device_supply(), which replaced the old function.
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Link: https://lore.kernel.org/r/20210103165541.784360-1-djrscally@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Selectors lower than linear_min_sel should not be considered invalid.
Thus return zero in case _regulator_list_voltage(),
regulator_list_hardware_vsel() or regulator_list_voltage_table()
receives such selectors as argument.
Fixes: bdcd1177578c ("regulator: core: validate selector against linear_min_sel")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/1606325147-606-1-git-send-email-claudiu.beznea@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Do not continue if selector has already been located. Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> Link: https://lore.kernel.org/r/1605290164-11556-1-git-send-email-claudiu.beznea@microchip.com Signed-off-by: Mark Brown <broonie@kernel.org>
Hi, This series adds support for ramp delay on mcp16502. It also adds some cleanup on mcp16502. Apart from that patches 1/6 fixes the selector validation in case the regulator::desc::linear_min_sel is not zero. Thank you, Claudiu Beznea Changes in v3: - fix compilation error in patch 5/6 Reported-by: kernel test robot <lkp@intel.com> Changes in v2: - rebase on top of regulator/for-next - checked 1/6 and 3/6 applies on top of regulator/for-5.10 Claudiu Beznea (6): regulator: core: validate selector against linear_min_sel regulator: core: do not continue if selector match regulator: mcp16502: add linear_min_sel regulator: mcp16502: adapt for get/set on other registers regulator: mcp16502: add support for ramp delay regulator: mcp16502: remove void documentation of struct mcp16502 drivers/regulator/core.c | 12 +++- drivers/regulator/helpers.c | 3 +- drivers/regulator/mcp16502.c | 135 ++++++++++++++++++++++++++++++++++++------- 3 files changed, 127 insertions(+), 23 deletions(-) -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel