[RFC 2/11] Linux FF: Linux effect status management
Elias Vanderstuyft
elias.vds at gmail.com
Tue Mar 4 13:19:39 CST 2014
a) This is a bug that is either the responsibility of the Linux
kernel, or of Wine:
It is caused by the following situation:
When uploading an effect, the specific kernel device
driver may return an error,
e.g. EINVAL for example when a periodic's effect period is
set to zero.
This error will then be returned by "ioctl(*(This->fd),
EVIOCSFF, &This->effect)".
With or without error, one can find out that
/drivers/input/ff-core.c:input_ff_upload(...) is called,
which will set effect->id >= 0, if it was set to -1 (=>
new effect created) by the user.
But in case of an error:
- Assume effect->id was set to -1 by the user:
The error is reported by ff->upload(...) at
/drivers/input/ff-core.c:167,
the effect->id will also be set >= 0 (*).
The offending effect will not be saved in the
ff->effects[] array (***).
- Assume effect->id was set >= 0 by the user (and
ff->effects[effect->id] is a valid existing effect):
The error is reported by ff->upload(...) at
/drivers/input/ff-core.c:167,
the effect->id will remain unchanged (**).
The offending effect will not overwrite the
ff->effects[effect->id] element (****).
Is this (see *, **, *** and ****) desired behavior?
- If yes:
Change the following in Wine's dinput/effect_linuxinput.c:84 :
LinuxInputEffectImpl *This =
impl_from_IDirectInputEffect(iface);
TRACE("(this=%p)\n", This);
if (ioctl(*(This->fd), EVIOCSFF, &This->effect) == -1) {
to :
LinuxInputEffectImpl *This =
impl_from_IDirectInputEffect(iface);
int effectId_old;
TRACE("(this=%p)\n", This);
effectId_old = This->effect.id;
if (ioctl(*(This->fd), EVIOCSFF, &This->effect) == -1) {
This->effect.id = effectId_old;
- If no for *:
Kernel code
/drivers/input/ff-core.c:input_ff_upload(...) has to be patched to
revert "effect->id" back to its original value set by the user,
which is only needed when the initial (by user) value
of "effect->id" was equal to -1.
- If no for **** (or maybe also ***):
ff->effects[effect->id] could be replaced by an
'empty' effect (however this can get complex because the effect's type
has to remain unchanged)
This would be a change in the kernel code
/drivers/input/ff-core.c:input_ff_upload(...).
- If no for **:
I don't really know. Discussion is needed.
- In my opinion, **, *** and **** are desired behavior,
while * should leave the effect->id at -1.
In that case, Wine's dinput implementation does not
have to be patched, and the kernel code only should apply a minor
patch.
=> This has been discussed (see
http://www.mail-archive.com/[email protected]/msg08513.html),
and the following is true:
My opinion appeared to be correct, but for to be sure, I was
recommended to apply the change in Wine as well.
b) Be more precise in returning errors.
In dinput/effect_linuxinput.c:89, change :
if (errno == ENOMEM) {
return DIERR_DEVICEFULL;
} else {
FIXME("Could not upload effect. Assuming a disconnected
device %d \"%s\".\n", *This->fd, strerror(errno));
return DIERR_INPUTLOST;
}
to :
switch (errno) {
case EINVAL:
TRACE("Could not upload effect: Invalid argument.\n");
return DIERR_INVALIDPARAM;
case ENOSPC:
TRACE("Could not upload effect: No space left on device.\n");
return DIERR_DEVICEFULL;
case ENOMEM:
TRACE("Could not upload effect: Out of memory.\n");
return DIERR_OUTOFMEMORY;
default:
FIXME("Could not upload effect. Assuming a
disconnected device %d \"%s\".\n", *This->fd, strerror(errno));
return DIERR_INPUTLOST;
}
c) The following in dinput/effect_linuxinput.c:336 :
if (res != DI_OK)
should be probably :
if (FAILED(res))
for example if a device reports S_FALSE because it has already
updated an identical effect.
The same for line 549:
if (retval != DI_OK)
should be then :
if (FAILED(retval))
Elias
-------------- next part --------------
///////////////////////////// Linux effect status management /////////////////////////////
a) This is a bug that is either the responsibility of the Linux kernel, or of Wine:
It is caused by the following situation:
When uploading an effect, the specific kernel device driver may return an error,
e.g. EINVAL for example when a periodic's effect period is set to zero.
This error will then be returned by "ioctl(*(This->fd), EVIOCSFF, &This->effect)".
With or without error, one can find out that /drivers/input/ff-core.c:input_ff_upload(...) is called,
which will set effect->id >= 0, if it was set to -1 (=> new effect created) by the user.
But in case of an error:
- Assume effect->id was set to -1 by the user:
The error is reported by ff->upload(...) at /drivers/input/ff-core.c:167,
the effect->id will also be set >= 0 (*).
The offending effect will not be saved in the ff->effects[] array (***).
- Assume effect->id was set >= 0 by the user (and ff->effects[effect->id] is a valid existing effect):
The error is reported by ff->upload(...) at /drivers/input/ff-core.c:167,
the effect->id will remain unchanged (**).
The offending effect will not overwrite the ff->effects[effect->id] element (****).
Is this (see *, **, *** and ****) desired behavior?
- If yes:
Change the following in Wine's dinput/effect_linuxinput.c:84 :
LinuxInputEffectImpl *This = impl_from_IDirectInputEffect(iface);
TRACE("(this=%p)\n", This);
if (ioctl(*(This->fd), EVIOCSFF, &This->effect) == -1) {
to :
LinuxInputEffectImpl *This = impl_from_IDirectInputEffect(iface);
int effectId_old;
TRACE("(this=%p)\n", This);
effectId_old = This->effect.id;
if (ioctl(*(This->fd), EVIOCSFF, &This->effect) == -1) {
This->effect.id = effectId_old;
- If no for *:
Kernel code /drivers/input/ff-core.c:input_ff_upload(...) has to be patched to revert "effect->id" back to its original value set by the user,
which is only needed when the initial (by user) value of "effect->id" was equal to -1.
- If no for **** (or maybe also ***):
ff->effects[effect->id] could be replaced by an 'empty' effect (however this can get complex because the effect's type has to remain unchanged)
This would be a change in the kernel code /drivers/input/ff-core.c:input_ff_upload(...).
- If no for **:
I don't really know. Discussion is needed.
- In my opinion, **, *** and **** are desired behavior, while * should leave the effect->id at -1.
In that case, Wine's dinput implementation does not have to be patched, and the kernel code only should apply a minor patch.
=> This has been discussed (see http://www.mail-archive.com/[email protected]/msg08513.html), and the following is true:
My opinion appeared to be correct, but for to be sure, I was recommended to apply the change in Wine as well.
b) Be more precise in returning errors.
In dinput/effect_linuxinput.c:89, change :
if (errno == ENOMEM) {
return DIERR_DEVICEFULL;
} else {
FIXME("Could not upload effect. Assuming a disconnected device %d \"%s\".\n", *This->fd, strerror(errno));
return DIERR_INPUTLOST;
}
to :
switch (errno) {
case EINVAL:
TRACE("Could not upload effect: Invalid argument.\n");
return DIERR_INVALIDPARAM;
case ENOSPC:
TRACE("Could not upload effect: No space left on device.\n");
return DIERR_DEVICEFULL;
case ENOMEM:
TRACE("Could not upload effect: Out of memory.\n");
return DIERR_OUTOFMEMORY;
default:
FIXME("Could not upload effect. Assuming a disconnected device %d \"%s\".\n", *This->fd, strerror(errno));
return DIERR_INPUTLOST;
}
c) The following in dinput/effect_linuxinput.c:336 :
if (res != DI_OK)
should be probably :
if (FAILED(res))
for example if a device reports S_FALSE because it has already updated an identical effect.
The same for line 549:
if (retval != DI_OK)
should be then :
if (FAILED(retval))
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