From patchwork Wed Jan 23 02:32:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniele Ceraolo Spurio X-Patchwork-Id: 10776477 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 466CE91E for ; Wed, 23 Jan 2019 02:32:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1D9712BDCF for ; Wed, 23 Jan 2019 02:32:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0E8EB2BDD7; Wed, 23 Jan 2019 02:32:45 +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 A85D02BDCF for ; Wed, 23 Jan 2019 02:32:44 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6043389C1B; Wed, 23 Jan 2019 02:32:43 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id 68A4789C1B for ; Wed, 23 Jan 2019 02:32:42 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Jan 2019 18:32:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,509,1539673200"; d="scan'208";a="118657346" Received: from dceraolo-linux.fm.intel.com ([10.1.27.134]) by fmsmga008.fm.intel.com with ESMTP; 22 Jan 2019 18:32:42 -0800 From: Daniele Ceraolo Spurio To: intel-gfx@lists.freedesktop.org Date: Tue, 22 Jan 2019 18:32:27 -0800 Message-Id: <20190123023227.8117-1-daniele.ceraolospurio@intel.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915/icl: do a posting read after irq install 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 When reading GEN11_GT_INTR_DWx closely after enabling the interrupts in gen11_irq_postinstall, the returned value is garbage. This can cause other parts of the setup code (e.g. gen11_reset_one_iir) to think that there are interrupts to be cleared when there are none. The garbage value is only seen on the first read done after the enable, so this looks like a posting issue. Adding a posting read after enabling the interrupts does indeed fix the problem. Note that the posting read has been purposely added outside of gen11_master_intr_enable since the issue has only been observed when the full interrupt setup is performed. Cc: Mika Kuoppala Signed-off-by: Daniele Ceraolo Spurio Acked-by: Chris Wilson Acked-by: Mika Kuoppala --- drivers/gpu/drm/i915/i915_irq.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 5fd5080c4ccb..7056ae2d1e0e 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -4089,6 +4089,7 @@ static int gen11_irq_postinstall(struct drm_device *dev) I915_WRITE(GEN11_DISPLAY_INT_CTL, GEN11_DISPLAY_IRQ_ENABLE); gen11_master_intr_enable(dev_priv->regs); + POSTING_READ(GEN11_GFX_MSTR_IRQ); return 0; }