From df3859a4aaa40783c50f43a6a8a53c7770d59ef1 Mon Sep 17 00:00:00 2001 From: Suraj Kandpal Date: Mon, 23 Sep 2024 08:40:08 +0530 Subject: [PATCH] drm/i915/hotplug: Add comment for XE_LPD+ SHPD_FILTER_CNT value Add the reason for having SHPD_FILTER_CNT value for XE_LPD+ and above as 250us instead of 500us. --v2 -Update commit message [Matt] Signed-off-by: Suraj Kandpal Reviewed-by: Matt Roper Link: https://patchwork.freedesktop.org/patch/msgid/20240923031007.1058072-4-suraj.kandpal@intel.com --- drivers/gpu/drm/i915/display/intel_hotplug_irq.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_hotplug_irq.c b/drivers/gpu/drm/i915/display/intel_hotplug_irq.c index 3a105cfd3c90..5d055dc9366f 100644 --- a/drivers/gpu/drm/i915/display/intel_hotplug_irq.c +++ b/drivers/gpu/drm/i915/display/intel_hotplug_irq.c @@ -1061,6 +1061,10 @@ static void mtp_hpd_irq_setup(struct drm_i915_private *i915) enabled_irqs = intel_hpd_enabled_irqs(i915, i915->display.hotplug.pch_hpd); hotplug_irqs = intel_hpd_hotplug_irqs(i915, i915->display.hotplug.pch_hpd); + /* + * Use 250us here to align with the DP1.4a(Table 3-4) spec as to what the + * SHPD_FILTER_CNT value should be. + */ intel_de_write(i915, SHPD_FILTER_CNT, SHPD_FILTER_CNT_250); mtp_hpd_invert(i915); -- 2.50.1