fix(core): while trying to increase the backlight brightness at T3W1 using the slider, it lags. The reason is implemented wait for making sure that the display gets refreshed during fade out/fade in transitions. The current implementation of the condition limits the wait only to such cases and not t
What the developer wrote
Authored by bleska
fix(core): while trying to increase the backlight brightness at T3W1 using the slider, it lags. The reason is implemented wait for making sure that the display gets refreshed during fade out/fade in transitions. The current implementation of the condition limits the wait only to such cases and not to all when the brightness needs to be increased.
[no changelog]
What changed, and why it matters
This is a one-line bugfix for the T3W1 hardware wallet's screen brightness slider. Previously, increasing brightness at all caused an unnecessary wait for the display to refresh, making the slider feel laggy. The fix narrows that wait so it only happens when turning the backlight on from fully off (e.g., during fade-in/fade-out transitions), not every time the brightness is raised. There is no security issue here.
No security action needed. Treat as a normal UI responsiveness fix.
Security signals we found
No strong security signals were identified.
Evidence from the diff
In core/embed/io/display/ltdc_dsi/display_driver.c, the condition guarding display_ensure_refreshed() before a backlight level change was changed from if (level > backlight_get()) to if (level > 0 && backlight_get() == 0). The old condition triggered a refresh-and-wait on any brightness increase; the new one only triggers it when the backlight is currently off and being turned on. This removes a UI lag source on the T3W1 model without changing the safety behavior for the off-to-on transition.
Changed components
core/embed/io/display/ltdc_dsi/display_driver.cT3W1 display/backlight driverInspect captured patch +1 / −1
diff --git a/core/embed/io/display/ltdc_dsi/display_driver.c b/core/embed/io/display/ltdc_dsi/display_driver.c
index 65941024b..a37d7bd38 100644
--- a/core/embed/io/display/ltdc_dsi/display_driver.c
+++ b/core/embed/io/display/ltdc_dsi/display_driver.c
@@ -450,7 +450,7 @@ bool display_set_backlight(uint8_t level) {
}
#ifdef USE_BACKLIGHT
- if (level > backlight_get()) {
+ if (level > 0 && backlight_get() == 0) {
display_ensure_refreshed();
}
Why this scored 18/100
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