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HID: pidff: Do not send effect envelope if it's empty

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[ Upstream commit 8876fc1884f5b39550c8387ff3176396c988541d ]

Envelope struct is always initialized, but the envelope itself is
optional as described in USB PID Device class definition 1.0.

5.1.1.1 Type Specific Block Offsets
...
4) Effects that do not use Condition Blocks use 1 Parameter Block and
an *optional* Envelope Block.

Sending out "empty" envelope breaks force feedback on some devices with
games that use SINE effect + offset to emulate constant force effect, as
well as generally breaking Constant/Periodic effects. One of the affected
brands is Moza Racing.

This change prevents the envelope from being sent if it contains all
0 values while keeping the old behavior of only sending it, if it differs
from the old one.

Changes in v6:
- Simplify the checks to make them clearer
- Fix possible null pointer dereference while calling
  pidff_needs_set_envelope

Signed-off-by: Tomasz Pakuła <tomasz.pakula.oficjalny@gmail.com>
Reviewed-by: Michał Kopeć <michal@nozomi.space>
Reviewed-by: Paul Dino Jones <paul@spacefreak18.xyz>
Tested-by: Paul Dino Jones <paul@spacefreak18.xyz>
Tested-by: Cristóferson Bueno <cbueno81@gmail.com>
Tested-by: Pablo Cisneros <patchkez@protonmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Tomasz Pakuła
2025-02-01 12:38:46 +01:00
committed by Greg Kroah-Hartman
parent 1c0785f164
commit d21ccf544c
1 changed files with 24 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
drivers/hid/usbhid/hid-pidff.c
View File

@@ -262,10 +262,22 @@ static void pidff_set_envelope_report(struct pidff_device *pidff,
static int pidff_needs_set_envelope(struct ff_envelope *envelope,
struct ff_envelope *old)
{
return envelope->attack_level != old->attack_level ||
envelope->fade_level != old->fade_level ||
bool needs_new_envelope;
needs_new_envelope = envelope->attack_level != 0 ||
envelope->fade_level != 0 ||
envelope->attack_length != 0 ||
envelope->fade_length != 0;
if (!needs_new_envelope)
return false;
if (!old)
return needs_new_envelope;
return envelope->attack_level != old->attack_level ||
envelope->fade_level != old->fade_level ||
envelope->attack_length != old->attack_length ||
envelope->fade_length != old->fade_length;
envelope->fade_length != old->fade_length;
}
/*
@@ -580,11 +592,9 @@ static int pidff_upload_effect(struct input_dev *dev, struct ff_effect *effect,
pidff_set_effect_report(pidff, effect);
if (!old || pidff_needs_set_constant(effect, old))
pidff_set_constant_force_report(pidff, effect);
if (!old ||
pidff_needs_set_envelope(&effect->u.constant.envelope,
&old->u.constant.envelope))
pidff_set_envelope_report(pidff,
&effect->u.constant.envelope);
if (pidff_needs_set_envelope(&effect->u.constant.envelope,
old ? &old->u.constant.envelope : NULL))
pidff_set_envelope_report(pidff, &effect->u.constant.envelope);
break;
case FF_PERIODIC:
@@ -619,11 +629,9 @@ static int pidff_upload_effect(struct input_dev *dev, struct ff_effect *effect,
pidff_set_effect_report(pidff, effect);
if (!old || pidff_needs_set_periodic(effect, old))
pidff_set_periodic_report(pidff, effect);
if (!old ||
pidff_needs_set_envelope(&effect->u.periodic.envelope,
&old->u.periodic.envelope))
pidff_set_envelope_report(pidff,
&effect->u.periodic.envelope);
if (pidff_needs_set_envelope(&effect->u.periodic.envelope,
old ? &old->u.periodic.envelope : NULL))
pidff_set_envelope_report(pidff, &effect->u.periodic.envelope);
break;
case FF_RAMP:
@@ -637,11 +645,9 @@ static int pidff_upload_effect(struct input_dev *dev, struct ff_effect *effect,
pidff_set_effect_report(pidff, effect);
if (!old || pidff_needs_set_ramp(effect, old))
pidff_set_ramp_force_report(pidff, effect);
if (!old ||
pidff_needs_set_envelope(&effect->u.ramp.envelope,
&old->u.ramp.envelope))
pidff_set_envelope_report(pidff,
&effect->u.ramp.envelope);
if (pidff_needs_set_envelope(&effect->u.ramp.envelope,
old ? &old->u.ramp.envelope : NULL))
pidff_set_envelope_report(pidff, &effect->u.ramp.envelope);
break;
case FF_SPRING: