diff options
| author | Maxim Kiselev <bigunclemax@gmail.com> | 2021-02-17 16:10:00 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-03 19:44:44 +0300 |
| commit | 828d937f52d82604dc430ed889b7dfb008c874ad (patch) | |
| tree | 382c3aea11ca809406ea2be8dc6f4d0815212b9f | |
| parent | e540571d692c7b3f7efc2d5208585d32753f67d2 (diff) | |
| download | linux-828d937f52d82604dc430ed889b7dfb008c874ad.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>
| -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 d168410e2338..2e6081e5ad0b 100644 --- a/drivers/gpio/gpio-pcf857x.c +++ b/drivers/gpio/gpio-pcf857x.c @@ -370,7 +370,7 @@ 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) |