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    SubjectRe: [RFC 0/7] Deal with iio trigger names
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    On 23/05/16 19:39, Crestez Dan Leonard wrote:
    > IIO documents that trigger names are unique but does not actually guarantee
    > this. You can easily create a software trigger with a duplicate name if you
    > enable CONFIG_IIO_HRTIMER_TRIGGER:
    >
    > mkdir /sys/kernel/config/iio/triggers/hrtimer/\
    > `cat /sys/bus/iio/devices/trigger0/name`
    >
    > You can also get in this situation if you connect two identical st_sensors.
    >
    > My attempt to fix this is by adding a new 'current_trigger_id' ABI which is a
    > numeric ID (X from triggerX) rather than a non-unique string. I tested that
    > this works as expected when connecting two LIS3DH to the same system. This is
    > in patches 4,5.
    >
    > In theory the current_trigger ABI could be overloaded to looks for something
    > matching "trigger[0-9]+" but this would be nastier. There would be a need to
    > prevent registering triggers that match that expression in order to prevent
    > stuff like:
    >
    > mkdir /sys/kernel/config/iio/triggers/hrtimer/trigger1
    >
    > Such an overload wouldn't work on read and make it impossible to unambigiously
    > determine the currently selected trigger.
    >
    >
    > Patch 6 disallows registering duplicate trigger names. This makes drivers
    > which currently do that break at probe time.
    >
    > Patch 7 attempts to ensure that all drivers include indio_dev->id when calling
    > iio_trigger_alloc. This obviously changes trigger names.
    >
    >
    > Either 4,5 or 6,7 fix this issue, but 4,5 causes fewer compat issues.
    >
    >
    > Patches 1,2,3 are just minor features in tools/generic_buffer. They supersede
    > the v2 I posted earlier:
    Please don't do this in future. When reviewing lots of series, one tends
    to relying on sorting by name to make sure you find the latest version of
    a series. Do this and people don't know there is a new version embedded in
    a different series (in this case I picked up V2 when you had found an issue
    in it).

    Jonathan
    >
    > https://www.spinics.net/lists/linux-iio/msg24867.html
    >
    > Crestez Dan Leonard (7):
    > iio: generic_buffer: Cleanup when receiving signals
    > iio: generic_buffer: Add --device-num option
    > iio: generic_buffer: Add --trigger-num option
    > iio: Add current_trigger_id alternative
    > iio: generic_buffer: Use current_trigger_id
    > iio: Refuse to register triggers with duplicate names
    > iio: Make trigger names unique
    >
    > Documentation/ABI/testing/sysfs-bus-iio | 9 +
    > Documentation/DocBook/iio.tmpl | 4 +-
    > drivers/iio/adc/max1027.c | 4 +-
    > drivers/iio/common/st_sensors/st_sensors_trigger.c | 2 +-
    > drivers/iio/industrialio-trigger.c | 136 ++++++++---
    > drivers/iio/light/gp2ap020a00f.c | 4 +-
    > tools/iio/generic_buffer.c | 269 ++++++++++++++-------
    > 7 files changed, 309 insertions(+), 119 deletions(-)
    >

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