When configured in filtered mode, the LVTS thermal controller will monitor the temperature from the sensors and trigger an interrupt once a thermal threshold is crossed.
Currently this is true even during suspend and resume. The problem with that is that when enabling the internal clock of the LVTS controller in lvts_ctrl_set_enable() during resume, the temperature reading can glitch and appear much higher than the real one, resulting in a spurious interrupt getting generated.
Disable the temperature monitoring and give some time for the signals to stabilize during suspend in order to prevent such spurious interrupts.
Cc: stable@vger.kernel.org Reported-by: Hsin-Te Yuan yuanhsinte@chromium.org Closes: https://lore.kernel.org/all/20241108-lvts-v1-1-eee339c6ca20@chromium.org/ Fixes: 8137bb90600d ("thermal/drivers/mediatek/lvts_thermal: Add suspend and resume") Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Signed-off-by: Nícolas F. R. A. Prado nfraprado@collabora.com --- drivers/thermal/mediatek/lvts_thermal.c | 36 +++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-)
diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c index 07f7f3b7a2fb569cfc300dc2126ea426e161adff..a1a438ebad33c1fff8ca9781e12ef9e278eef785 100644 --- a/drivers/thermal/mediatek/lvts_thermal.c +++ b/drivers/thermal/mediatek/lvts_thermal.c @@ -860,6 +860,32 @@ static int lvts_ctrl_init(struct device *dev, struct lvts_domain *lvts_td, return 0; }
+static void lvts_ctrl_monitor_enable(struct device *dev, struct lvts_ctrl *lvts_ctrl, bool enable) +{ + /* + * Bitmaps to enable each sensor on filtered mode in the MONCTL0 + * register. + */ + static const u8 sensor_filt_bitmap[] = { BIT(0), BIT(1), BIT(2), BIT(3) }; + u32 sensor_map = 0; + int i; + + if (lvts_ctrl->mode != LVTS_MSR_FILTERED_MODE) + return; + + if (enable) { + lvts_for_each_valid_sensor(i, lvts_ctrl) + sensor_map |= sensor_filt_bitmap[i]; + } + + /* + * Bits: + * 9: Single point access flow + * 0-3: Enable sensing point 0-3 + */ + writel(sensor_map | BIT(9), LVTS_MONCTL0(lvts_ctrl->base)); +} + /* * At this point the configuration register is the only place in the * driver where we write multiple values. Per hardware constraint, @@ -1381,8 +1407,11 @@ static int lvts_suspend(struct device *dev)
lvts_td = dev_get_drvdata(dev);
- for (i = 0; i < lvts_td->num_lvts_ctrl; i++) + for (i = 0; i < lvts_td->num_lvts_ctrl; i++) { + lvts_ctrl_monitor_enable(dev, &lvts_td->lvts_ctrl[i], false); + usleep_range(100, 200); lvts_ctrl_set_enable(&lvts_td->lvts_ctrl[i], false); + }
clk_disable_unprepare(lvts_td->clk);
@@ -1400,8 +1429,11 @@ static int lvts_resume(struct device *dev) if (ret) return ret;
- for (i = 0; i < lvts_td->num_lvts_ctrl; i++) + for (i = 0; i < lvts_td->num_lvts_ctrl; i++) { lvts_ctrl_set_enable(&lvts_td->lvts_ctrl[i], true); + usleep_range(100, 200); + lvts_ctrl_monitor_enable(dev, &lvts_td->lvts_ctrl[i], true); + }
return 0; }