| Message ID | 1387184235-20169-3-git-send-email-ospite@studenti.unina.it (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Antonio, On Mon, Dec 16, 2013 at 09:57:15AM +0100, Antonio Ospite wrote: > @@ -181,7 +181,7 @@ at a time using the typical read(2) functionality. For that, you would > replace the read above with something like > > struct js_event mybuffer[0xff]; > - int i = read (fd, mybuffer, sizeof(struct mybuffer)); > + int i = read (fd, mybuffer, ARRAY_SIZE(mybuffer)); > This is wrong, as ARRAY_SIZE(mybuffer) would be 0xff and not the size of buffer in bytes. I'll fix it up. Thanks.
On Mon, 16 Dec 2013 01:51:41 -0800 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > Hi Antonio, > > On Mon, Dec 16, 2013 at 09:57:15AM +0100, Antonio Ospite wrote: > > @@ -181,7 +181,7 @@ at a time using the typical read(2) functionality. For that, you would > > replace the read above with something like > > > > struct js_event mybuffer[0xff]; > > - int i = read (fd, mybuffer, sizeof(struct mybuffer)); > > + int i = read (fd, mybuffer, ARRAY_SIZE(mybuffer)); > > > > This is wrong, as ARRAY_SIZE(mybuffer) would be 0xff and not the size of > buffer in bytes. I'll fix it up. > > Thanks. You're right of course, thank you. Ciao, Antonio
diff --git a/Documentation/input/joystick-api.txt b/Documentation/input/joystick-api.txt index f95f648..47e60a5 100644 --- a/Documentation/input/joystick-api.txt +++ b/Documentation/input/joystick-api.txt @@ -23,7 +23,7 @@ By default, the device is opened in blocking mode. ~~~~~~~~~~~~~~~~ struct js_event e; - read (fd, &e, sizeof(struct js_event)); + read (fd, &e, sizeof(e)); where js_event is defined as @@ -34,8 +34,8 @@ where js_event is defined as __u8 number; /* axis/button number */ }; -If the read is successful, it will return sizeof(struct js_event), unless -you wanted to read more than one event per read as described in section 3.1. +If the read is successful, it will return sizeof(e), unless you wanted to read +more than one event per read as described in section 3.1. 2.1 js_event.type @@ -144,7 +144,7 @@ all events on the queue (that is, until you get a -1). For example, while (1) { - while (read (fd, &e, sizeof(struct js_event)) > 0) { + while (read (fd, &e, sizeof(e)) > 0) { process_event (e); } /* EAGAIN is returned when the queue is empty */ @@ -181,7 +181,7 @@ at a time using the typical read(2) functionality. For that, you would replace the read above with something like struct js_event mybuffer[0xff]; - int i = read (fd, mybuffer, sizeof(struct mybuffer)); + int i = read (fd, mybuffer, ARRAY_SIZE(mybuffer)); In this case, read would return -1 if the queue was empty, or some other value in which the number of events read would be i /
Use the preferred style sizeof(VARIABLE) instead of sizeof(TYPE) in the joystick API documentation, Documentation/CodingStyle states that this is the preferred style for allocations but using it elsewhere is good too. Also fix some errors like "sizeof(struct mybuffer)" which didn't mean anything. Signed-off-by: Antonio Ospite <ospite@studenti.unina.it> --- Documentation/input/joystick-api.txt | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)