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| author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2019-02-15 09:17:36 +0100 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2019-02-20 10:53:52 +0100 |
| commit | 9aac1e336c3ab3824f646224f4b2309b63c51668 (patch) | |
| tree | dc95e52cb2329c95d96a8eaefdbb34751076234d /Documentation/driver-api/gpio | |
| parent | 2a9a2f27d35af6c44c2e38437c855f55390c3439 (diff) | |
| download | linux-9aac1e336c3ab3824f646224f4b2309b63c51668.tar.gz | |
Documentation: gpio: legacy: Don't use POLLERR for poll(2)
According to the manpage of poll(2) and also looking at the respective
syscall providing POLLERR in .events is a no-op. So don't recommend
using it.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/driver-api/gpio')
| -rw-r--r-- | Documentation/driver-api/gpio/legacy.rst | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/Documentation/driver-api/gpio/legacy.rst b/Documentation/driver-api/gpio/legacy.rst index 5e9421e05f1d..9bc34ba697d9 100644 --- a/Documentation/driver-api/gpio/legacy.rst +++ b/Documentation/driver-api/gpio/legacy.rst @@ -690,11 +690,10 @@ and have the following read/write attributes: and if it has been configured to generate interrupts (see the description of "edge"), you can poll(2) on that file and poll(2) will return whenever the interrupt was triggered. If - you use poll(2), set the events POLLPRI and POLLERR. If you - use select(2), set the file descriptor in exceptfds. After - poll(2) returns, either lseek(2) to the beginning of the sysfs - file and read the new value or close the file and re-open it - to read the value. + you use poll(2), set the events POLLPRI. If you use select(2), + set the file descriptor in exceptfds. After poll(2) returns, + either lseek(2) to the beginning of the sysfs file and read the + new value or close the file and re-open it to read the value. "edge" ... reads as either "none", "rising", "falling", or "both". Write these strings to select the signal edge(s) |