From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: [PATCH] drm/i915: Fix irq enable tracking in driver load Date: Wed, 27 Aug 2014 10:11:34 +0200 Message-ID: <1409127094-5843-1-git-send-email-daniel.vetter@ffwll.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-we0-f174.google.com (mail-we0-f174.google.com [74.125.82.174]) by gabe.freedesktop.org (Postfix) with ESMTP id 497A66E104 for ; Wed, 27 Aug 2014 01:11:17 -0700 (PDT) Received: by mail-we0-f174.google.com with SMTP id x48so15786059wes.19 for ; Wed, 27 Aug 2014 01:11:16 -0700 (PDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Intel Graphics Development Cc: Daniel Vetter , Oliver Hartkopp List-Id: intel-gfx@lists.freedesktop.org A bunch of warnings fire on some ->irq_postinstall hooks since those can enable interrupts (e.g. rps interrupts). And then our ordering self-checks fire and complain. To fix that set the tracking boolen before enabling the irqs with drm_irq_install. Quoting the discussion with Jesse why that's safe: On Tue, Aug 26, 2014 at 11:18 PM, Jesse Barnes wrote: > Yes, it might work, but if you look through the history, we set this > field carefully; first to true in the irq_init code, then to false only > after the irq_install completes. So I think your fragility arguments > apply to this change too. Well we've done it in 4 commits or so, but currently we have: - Set irqs_disabled to true early in driver load to make sure checks that. That's done in irq_init, which is totally not the function that enables interrupts, only the function that initializes all the vtables and similar things. We actually have a fairly sane naming scheme nowadays (not fully consistent ofc): _init is sw setup, _enable/_hw_init is the actual hw setup. That is done in 95f25beddba2ec9510b249740bacc11eca70cf75 - Set irqs_disabled to false right after the irqs are actually enabled. This is done in ed2e6df18935beb3d63613c50103bf9757b2aa85 So my change should only move the flag change over the ->preinstall and ->postinstall hooks. I've done a little audit and didn't spot anything amiss. Furthermore the runtime pm setup already clears irqs_disabled _before_ calling these two hooks. This regression has been introduced in commit ed2e6df18935beb3d63613c50103bf9757b2aa85 Author: Jesse Barnes Date: Fri Jun 20 09:39:36 2014 -0700 drm/i915: clear pm._irqs_disabled field after installing IRQs Cc: Jesse Barnes Cc: Oliver Hartkopp Tested-by: Oliver Hartkopp Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_dma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 3b24e3bb2106..498980661b2f 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1336,12 +1336,17 @@ static int i915_load_modeset_init(struct drm_device *dev) intel_power_domains_init_hw(dev_priv); + /* + * We enable some interrupt sources in our postinstall hooks, so mark + * interrupts as enabled _before_ actually enabling them to avoid + * special cases in our ordering checks. + */ + dev_priv->pm._irqs_disabled = false; + ret = drm_irq_install(dev, dev->pdev->irq); if (ret) goto cleanup_gem_stolen; - dev_priv->pm._irqs_disabled = false; - /* Important: The output setup functions called by modeset_init need * working irqs for e.g. gmbus and dp aux transfers. */ intel_modeset_init(dev); -- 2.0.1