[v1] gpiolib: use a read-write semaphore to protect the GPIO device list

[PATCH 0/2] gpiolib: use a read-write semaphore to protect the GPIO device list

Bartosz Golaszewski posted 2 patches 1 year, 12 months ago

Diff against v2
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drivers/gpio/gpiolib-sysfs.c |  2 +-
drivers/gpio/gpiolib.c       | 58 ++++++++++++++++++++----------------
drivers/gpio/gpiolib.h       |  2 +-
3 files changed, 34 insertions(+), 28 deletions(-)

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[PATCH 0/2] gpiolib: use a read-write semaphore to protect the GPIO device list

Posted by Bartosz Golaszewski 1 year, 12 months ago

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

I'm still figuring out how to keep GPIO descriptors coherent while
(mostly) lockless. In the meantime, I found a potential race-condition
during GPIO descriptor lookup and also figured that the correct way to
protect the GPIO device list is actually a read-write semaphore as we're
not modifying the list very often and readers should be able to iterate
over it concurrently.

Bartosz Golaszewski (2):
  gpiolib: replace the GPIO device mutex with a read-write semaphore
  gpiolib: pin GPIO devices in place during descriptor lookup

 drivers/gpio/gpiolib-sysfs.c |  2 +-
 drivers/gpio/gpiolib.c       | 58 ++++++++++++++++++++----------------
 drivers/gpio/gpiolib.h       |  2 +-
 3 files changed, 34 insertions(+), 28 deletions(-)

-- 
2.40.1