| Message ID | 20160421031826.GA6719@jelly.local (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi On Thu, Apr 21, 2016 at 5:18 AM, Peter Hutterer <peter.hutterer@who-t.net> wrote: > The current implementation does not match the most intuitive reading of the > documentation. The documentation suggests that anything after FOO_CNT would > be reset to zeroes. The implementation however works on long boundaries > instead. > > For example, a client requesting the EV_REL mask will see the first 64 bits > set to one in the default mask, everything else is zero. Setting a mask will > apply the mask for the first 64 bits, the others are cleared. > > There are few use-cases where this actually matters to a client - if a > device doesn't have the event code anyway the mask doesn't matter. So change > two absolute statements to a "may" to indicate that bits may or may not be > set. > > Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net> > --- > include/uapi/linux/input.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Thanks! David > diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h > index 0111384..6069524 100644 > --- a/include/uapi/linux/input.h > +++ b/include/uapi/linux/input.h > @@ -181,7 +181,7 @@ struct input_mask { > * The default event mask for a client has all bits set, i.e. all events > * are forwarded to the client. If the kernel is queried for an unknown > * event type or if the receive buffer is larger than the number of > - * event codes known to the kernel, the kernel returns all zeroes for those > + * event codes known to the kernel, the kernel may return zeroes for those > * codes. > * > * At maximum, codes_size bytes are copied. > @@ -204,7 +204,7 @@ struct input_mask { > * is unknown to the kernel, or if the number of event codes specified in > * the mask is bigger than what is known to the kernel, the ioctl is still > * accepted and applied. However, any unknown codes are left untouched and > - * stay cleared. That means, the kernel always filters unknown codes > + * may be cleared. That means, the kernel always filters unknown codes > * regardless of what the client requests. If the new mask doesn't cover > * all known event-codes, all remaining codes are automatically cleared and > * thus filtered. > -- > 2.7.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Apr 21, 2016 at 10:09:11AM +0200, David Herrmann wrote: > Hi > > On Thu, Apr 21, 2016 at 5:18 AM, Peter Hutterer > <peter.hutterer@who-t.net> wrote: > > The current implementation does not match the most intuitive reading of the > > documentation. The documentation suggests that anything after FOO_CNT would > > be reset to zeroes. The implementation however works on long boundaries > > instead. > > > > For example, a client requesting the EV_REL mask will see the first 64 bits > > set to one in the default mask, everything else is zero. Setting a mask will > > apply the mask for the first 64 bits, the others are cleared. > > > > There are few use-cases where this actually matters to a client - if a > > device doesn't have the event code anyway the mask doesn't matter. So change > > two absolute statements to a "may" to indicate that bits may or may not be > > set. > > > > Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net> > > --- > > include/uapi/linux/input.h | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > Reviewed-by: David Herrmann <dh.herrmann@gmail.com> I just found this one on one of my branches. Dmitry, want to merge this one? Cheers, Peter > > Thanks! > David > > > diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h > > index 0111384..6069524 100644 > > --- a/include/uapi/linux/input.h > > +++ b/include/uapi/linux/input.h > > @@ -181,7 +181,7 @@ struct input_mask { > > * The default event mask for a client has all bits set, i.e. all events > > * are forwarded to the client. If the kernel is queried for an unknown > > * event type or if the receive buffer is larger than the number of > > - * event codes known to the kernel, the kernel returns all zeroes for those > > + * event codes known to the kernel, the kernel may return zeroes for those > > * codes. > > * > > * At maximum, codes_size bytes are copied. > > @@ -204,7 +204,7 @@ struct input_mask { > > * is unknown to the kernel, or if the number of event codes specified in > > * the mask is bigger than what is known to the kernel, the ioctl is still > > * accepted and applied. However, any unknown codes are left untouched and > > - * stay cleared. That means, the kernel always filters unknown codes > > + * may be cleared. That means, the kernel always filters unknown codes > > * regardless of what the client requests. If the new mask doesn't cover > > * all known event-codes, all remaining codes are automatically cleared and > > * thus filtered. > > -- > > 2.7.3 > > -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h index 0111384..6069524 100644 --- a/include/uapi/linux/input.h +++ b/include/uapi/linux/input.h @@ -181,7 +181,7 @@ struct input_mask { * The default event mask for a client has all bits set, i.e. all events * are forwarded to the client. If the kernel is queried for an unknown * event type or if the receive buffer is larger than the number of - * event codes known to the kernel, the kernel returns all zeroes for those + * event codes known to the kernel, the kernel may return zeroes for those * codes. * * At maximum, codes_size bytes are copied. @@ -204,7 +204,7 @@ struct input_mask { * is unknown to the kernel, or if the number of event codes specified in * the mask is bigger than what is known to the kernel, the ioctl is still * accepted and applied. However, any unknown codes are left untouched and - * stay cleared. That means, the kernel always filters unknown codes + * may be cleared. That means, the kernel always filters unknown codes * regardless of what the client requests. If the new mask doesn't cover * all known event-codes, all remaining codes are automatically cleared and * thus filtered.
The current implementation does not match the most intuitive reading of the documentation. The documentation suggests that anything after FOO_CNT would be reset to zeroes. The implementation however works on long boundaries instead. For example, a client requesting the EV_REL mask will see the first 64 bits set to one in the default mask, everything else is zero. Setting a mask will apply the mask for the first 64 bits, the others are cleared. There are few use-cases where this actually matters to a client - if a device doesn't have the event code anyway the mask doesn't matter. So change two absolute statements to a "may" to indicate that bits may or may not be set. Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net> --- include/uapi/linux/input.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)