diff options
| author | Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com> | 2026-05-22 09:49:35 +0200 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com> | 2026-05-28 15:23:39 +0200 |
| commit | bbec30f7e19d9a1c604da7164b8057ccee590e72 (patch) | |
| tree | 01dabc0c8d4a742a7d9a0266579dc91cd1e3eec7 | |
| parent | dac917ed5aead741004db8d0d5151dd577802df8 (diff) | |
gpio: shared: undo the vote of the proxy on GPIO free
When the user of a shared GPIO managed by gpio-shared-proxy calls
gpiod_put() to release it, we never undo the potential "vote" for
driving the shared line "high". In the free() callback, check if this
proxy voted for "high" and - if so - decrease the number of votes and
potentially revert the value to low if this is the last user.
Cc: stable@vger.kernel.org
Fixes: e992d54c6f97 ("gpio: shared-proxy: implement the shared GPIO proxy driver")
Closes: https://sashiko.dev/#/patchset/20260513-gpio-shared-dynamic-voting-v1-1-8e1c49961b7d%40oss.qualcomm.com
Reviewed-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/20260522-gpio-shared-free-vote-v3-1-8a4fddc6bedb@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
| -rw-r--r-- | drivers/gpio/gpio-shared-proxy.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-shared-proxy.c b/drivers/gpio/gpio-shared-proxy.c index 29d7d2e4dfc0..6941e4be6cf1 100644 --- a/drivers/gpio/gpio-shared-proxy.c +++ b/drivers/gpio/gpio-shared-proxy.c @@ -103,9 +103,18 @@ static void gpio_shared_proxy_free(struct gpio_chip *gc, unsigned int offset) { struct gpio_shared_proxy_data *proxy = gpiochip_get_data(gc); struct gpio_shared_desc *shared_desc = proxy->shared_desc; + int ret; guard(gpio_shared_desc_lock)(shared_desc); + if (proxy->voted_high) { + ret = gpio_shared_proxy_set_unlocked(proxy, + shared_desc->can_sleep ? gpiod_set_value_cansleep : gpiod_set_value, 0); + if (ret) + dev_err(proxy->dev, + "Failed to unset the shared GPIO value on release: %d\n", ret); + } + proxy->shared_desc->usecnt--; dev_dbg(proxy->dev, "Shared GPIO freed, number of users: %u\n", |