| Message ID | 20190215081736.7291-1-u.kleine-koenig@pengutronix.de |
|---|---|
| State | New |
| Headers | show |
| Series | Documentation: gpio: legacy: Don't use POLLERR for poll(2) | expand |
pt., 15 lut 2019 o 09:17 Uwe Kleine-König <u.kleine-koenig@pengutronix.de> napisał(a): > > 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> > --- > Documentation/driver-api/gpio/legacy.rst | 9 ++++----- > 1 file 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) > -- > 2.20.1 > Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
On Fri, Feb 15, 2019 at 9:17 AM Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote: > 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> Patch applied with Bartosz review tag. Yours, Linus Walleij
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)
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> --- Documentation/driver-api/gpio/legacy.rst | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)