From patchwork Tue Oct 2 14:05:49 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Mika Kuoppala X-Patchwork-Id: 10623753 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 23A9715A6 for ; Tue, 2 Oct 2018 14:06:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0C8AA1FF62 for ; Tue, 2 Oct 2018 14:06:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 00B521FF66; Tue, 2 Oct 2018 14:06:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A21881FF62 for ; Tue, 2 Oct 2018 14:06:26 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AB3576E315; Tue, 2 Oct 2018 14:06:25 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTPS id B32AC6E315 for ; Tue, 2 Oct 2018 14:06:23 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Oct 2018 07:06:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,332,1534834800"; d="scan'208";a="88519892" Received: from rosetta.fi.intel.com ([10.237.72.186]) by orsmga003.jf.intel.com with ESMTP; 02 Oct 2018 07:06:19 -0700 Received: by rosetta.fi.intel.com (Postfix, from userid 1000) id 5CB9E840685; Tue, 2 Oct 2018 17:05:54 +0300 (EEST) From: Mika Kuoppala To: intel-gfx@lists.freedesktop.org Date: Tue, 2 Oct 2018 17:05:49 +0300 Message-Id: <20181002140552.1051-1-mika.kuoppala@linux.intel.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 1/4] drm/i915/gen8: Disable master intr before reading X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Disable master interrupt before reading level indications. This will close a race where we get a level indication between reading and disabling, generating an extra interrupt where we could have avoided one. Further, as the reading acts also as a post, replace the write/post on the irq reset with the helper. On enabling side, posting doesn't serve any purpose so it can also be replaced with helper. Cc: Chris Wilson Cc: Ville Syrjälä Signed-off-by: Mika Kuoppala Reviewed-by: Chris Wilson --- drivers/gpu/drm/i915/i915_irq.c | 36 ++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 2e242270e270..cbc04dd59041 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -2887,21 +2887,39 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl) return ret; } +static inline u32 gen8_master_intr_disable(void __iomem * const regs) +{ + raw_reg_write(regs, GEN8_MASTER_IRQ, 0); + + /* + * Now with master disabled, get a sample of level indications + * for this interrupt. Indications will be cleared on related acks. + * New indications can and will light up during processing, + * and will generate new interrupt after enabling master. + */ + return raw_reg_read(regs, GEN8_MASTER_IRQ); +} + +static inline void gen8_master_intr_enable(void __iomem * const regs) +{ + raw_reg_write(regs, GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL); +} + static irqreturn_t gen8_irq_handler(int irq, void *arg) { struct drm_i915_private *dev_priv = to_i915(arg); + void __iomem * const regs = dev_priv->regs; u32 master_ctl; u32 gt_iir[4]; if (!intel_irqs_enabled(dev_priv)) return IRQ_NONE; - master_ctl = I915_READ_FW(GEN8_MASTER_IRQ); - master_ctl &= ~GEN8_MASTER_IRQ_CONTROL; - if (!master_ctl) + master_ctl = gen8_master_intr_disable(regs); + if (!master_ctl) { + gen8_master_intr_enable(regs); return IRQ_NONE; - - I915_WRITE_FW(GEN8_MASTER_IRQ, 0); + } /* Find, clear, then process each source of interrupt */ gen8_gt_irq_ack(dev_priv, master_ctl, gt_iir); @@ -2913,7 +2931,7 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg) enable_rpm_wakeref_asserts(dev_priv); } - I915_WRITE_FW(GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL); + gen8_master_intr_enable(regs); gen8_gt_irq_handler(dev_priv, master_ctl, gt_iir); @@ -3598,8 +3616,7 @@ static void gen8_irq_reset(struct drm_device *dev) struct drm_i915_private *dev_priv = to_i915(dev); int pipe; - I915_WRITE(GEN8_MASTER_IRQ, 0); - POSTING_READ(GEN8_MASTER_IRQ); + gen8_master_intr_disable(dev_priv->regs); gen8_gt_irq_reset(dev_priv); @@ -4244,8 +4261,7 @@ static int gen8_irq_postinstall(struct drm_device *dev) if (HAS_PCH_SPLIT(dev_priv)) ibx_irq_postinstall(dev); - I915_WRITE(GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL); - POSTING_READ(GEN8_MASTER_IRQ); + gen8_master_intr_enable(dev_priv->regs); return 0; }