linux-kernel - [PATCH v4 0/4] nvmem/gpio: fix resource management

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Date:   Thu, 20 Feb 2020 11:01:37 +0100
From:   Bartosz Golaszewski <brgl@...ev.pl>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Khouloud Touil <ktouil@...libre.com>,
        Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: [PATCH v4 0/4] nvmem/gpio: fix resource management

From: Bartosz Golaszewski <bgolaszewski@...libre.com>

This series addresses a couple problems with memory management in nvmem
core.

First we fix a memory leak introduced in this release cycle. Next we extend
the GPIO framework to use reference counting for GPIO descriptors. We then
use it to fix the resource management problem with the write-protect pin.

Finally we add some readability tweaks and a comment clearing up some
confusion about resource management.

While the memory leak with wp-gpios is now in mainline - I'm not sure how
to go about applying the kref patch. This is theoretically a new feature
but it's also the cleanest way of fixing the problem.

v1 -> v2:
- make gpiod_ref() helper return
- reorganize the series for easier merging
- fix another memory leak

v2 -> v3:
- drop incorrect patches
- add a patch adding a comment about resource management
- extend the GPIO kref patch: only increment the reference count if the
  descriptor is associated with a requested line

v3 -> v4:
- fixed the return value in error path in nvmem_register()
- dropped patches already applied to the nvmem tree
- dropped the patch adding the comment about resource management

Bartosz Golaszewski (3):
  nvmem: fix memory leak in error path
  gpiolib: use kref in gpio_desc
  nvmem: increase the reference count of a gpio passed over config

Khouloud Touil (1):
  nvmem: release the write-protect pin

 drivers/gpio/gpiolib.c        | 36 ++++++++++++++++++++++++++++++++---
 drivers/gpio/gpiolib.h        |  1 +
 drivers/nvmem/core.c          |  8 ++++++--
 include/linux/gpio/consumer.h |  1 +
 4 files changed, 41 insertions(+), 5 deletions(-)

-- 
2.25.0