Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932541AbcC2Uqg (ORCPT ); Tue, 29 Mar 2016 16:46:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36717 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932404AbcC2Uqe (ORCPT ); Tue, 29 Mar 2016 16:46:34 -0400 From: Lyude To: intel-gfx@lists.freedesktop.org Cc: Lyude , stable@vger.kernel.org, Daniel Vetter , Jani Nikula , David Airlie , dri-devel@lists.freedesktop.org (open list:INTEL DRM DRIVERS (excluding Poulsbo, Moorestow...), linux-kernel@vger.kernel.org (open list)) Subject: [PATCH] drm/i915/vlv: Enable/disable VGA hotplugging properly Date: Tue, 29 Mar 2016 16:46:30 -0400 Message-Id: <1459284390-14485-1-git-send-email-cpaul@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2315 Lines: 69 On Valleyview, VGA hotplugging is controlled through a seperate register than everything else, VLV_ADPA, which must be explicitly set. While VGA hotplugging worked(ish) before, it looks like that was mainly because we'd unintentionally enable it in valleyview_crt_detect_hotplug() when we did a force trigger. This doesn't work reliably enough because whenever the display powerwell on vlv gets disabled, the values set in VLV_ADPA get cleared and consequently VGA hotplugging gets disabled. This causes bugs such as one we found on an Intel NUC, where doing the following sequence of hotplugs: - Disconnect all monitors - Connect VGA - Disconnect VGA - Connect HDMI Would result in hotplugging getting disabled, due to the display powerwells getting toggled in the process of connecting HDMI. CC: stable@vger.kernel.org Signed-off-by: Lyude --- drivers/gpu/drm/i915/i915_irq.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 5aa4239..60592a4 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -3611,6 +3611,7 @@ static void valleyview_display_irqs_install(struct drm_i915_private *dev_priv) { u32 pipestat_mask; u32 iir_mask; + u32 adpa_reg; enum pipe pipe; pipestat_mask = PIPESTAT_INT_STATUS_MASK | @@ -3627,6 +3628,12 @@ static void valleyview_display_irqs_install(struct drm_i915_private *dev_priv) for_each_pipe(dev_priv, pipe) i915_enable_pipestat(dev_priv, pipe, pipestat_mask); + if (IS_VALLEYVIEW(dev_priv)) { + adpa_reg = I915_READ(VLV_ADPA); + adpa_reg |= ADPA_CRT_HOTPLUG_ENABLE; + I915_WRITE(VLV_ADPA, adpa_reg); + } + iir_mask = I915_DISPLAY_PORT_INTERRUPT | I915_DISPLAY_PIPE_A_EVENT_INTERRUPT | I915_DISPLAY_PIPE_B_EVENT_INTERRUPT; @@ -3645,8 +3652,15 @@ static void valleyview_display_irqs_uninstall(struct drm_i915_private *dev_priv) { u32 pipestat_mask; u32 iir_mask; + u32 adpa_reg; enum pipe pipe; + if (IS_VALLEYVIEW(dev_priv)) { + adpa_reg = I915_READ(VLV_ADPA); + adpa_reg &= ~ADPA_CRT_HOTPLUG_ENABLE; + I915_WRITE(VLV_ADPA, adpa_reg); + } + iir_mask = I915_DISPLAY_PORT_INTERRUPT | I915_DISPLAY_PIPE_A_EVENT_INTERRUPT | I915_DISPLAY_PIPE_B_EVENT_INTERRUPT; -- 2.5.5