diff options
| author | Maxim Kiselev <bigunclemax@gmail.com> | 2021-02-17 16:10:00 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-04 11:39:56 +0300 |
| commit | 8aad9180a0a42fd7df070e4170ae63702b21ede5 (patch) | |
| tree | cfa7ec920ae48935a265589a68c824be51f2e63a /drivers | |
| parent | 5fbc9a3a040216dfcaac2833074cac8bdc6d14f4 (diff) | |
| download | linux-8aad9180a0a42fd7df070e4170ae63702b21ede5.tar.xz | |
gpio: pcf857x: Fix missing first interrupt
commit a8002a35935aaefcd6a42ad3289f62bab947f2ca upstream.
If no n_latch value will be provided at driver probe then all pins will
be used as an input:
gpio->out = ~n_latch;
In that case initial state for all pins is "one":
gpio->status = gpio->out;
So if pcf857x IRQ happens with change pin value from "zero" to "one"
then we miss it, because of "one" from IRQ and "one" from initial state
leaves corresponding pin unchanged:
change = (gpio->status ^ status) & gpio->irq_enabled;
The right solution will be to read actual state at driver probe.
Cc: stable@vger.kernel.org
Fixes: 6e20a0a429bd ("gpio: pcf857x: enable gpio_to_irq() support")
Signed-off-by: Maxim Kiselev <bigunclemax@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpio/gpio-pcf857x.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c index 68a35b65925a..d3fcc0d15eb8 100644 --- a/drivers/gpio/gpio-pcf857x.c +++ b/drivers/gpio/gpio-pcf857x.c @@ -357,7 +357,7 @@ static int pcf857x_probe(struct i2c_client *client, * reset state. Otherwise it flags pins to be driven low. */ gpio->out = ~n_latch; - gpio->status = gpio->out; + gpio->status = gpio->read(gpio->client); status = devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio); if (status < 0) |