From patchwork Thu Jun 14 17:56:25 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= X-Patchwork-Id: 10464913 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5177360348 for ; Thu, 14 Jun 2018 17:56:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3A36D28756 for ; Thu, 14 Jun 2018 17:56:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2E4FE2879B; Thu, 14 Jun 2018 17:56:31 +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 C1B8928756 for ; Thu, 14 Jun 2018 17:56:30 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0218B6E274; Thu, 14 Jun 2018 17:56:30 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id F365C6E274 for ; Thu, 14 Jun 2018 17:56:28 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Jun 2018 10:56:28 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,222,1526367600"; d="scan'208";a="49042335" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by orsmga007.jf.intel.com with SMTP; 14 Jun 2018 10:56:26 -0700 Received: by stinkbox (sSMTP sendmail emulation); Thu, 14 Jun 2018 20:56:25 +0300 From: Ville Syrjala To: intel-gfx@lists.freedesktop.org Date: Thu, 14 Jun 2018 20:56:25 +0300 Message-Id: <20180614175625.1615-1-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20180611200258.27121-2-ville.syrjala@linux.intel.com> References: <20180611200258.27121-2-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v2 2/4] drm/i915: Fix hotplug irq ack on i965/g4x 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: , Cc: stable@vger.kernel.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP From: Ville Syrjälä Just like with PIPESTAT, the edge triggered IIR on i965/g4x also causes problems for hotplug interrupts. To make sure we don't get the IIR port interrupt bit stuck low with the ISR bit high we must force an edge in ISR. Unfortunately we can't borrow the PIPESTAT trick and toggle the enable bits in PORT_HOTPLUG_EN as that act itself generates hotplug interrupts. Instead we just have to loop until we've cleared PORT_HOTPLUG_STAT, or we just give up and WARN. v2: Don't frob with PORT_HOTPLUG_EN Cc: stable@vger.kernel.org Signed-off-by: Ville Syrjälä Reviewed-by: Imre Deak --- drivers/gpu/drm/i915/i915_irq.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index d5aee0b74f4b..55a4d4f3fbb2 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1998,10 +1998,38 @@ static void valleyview_pipestat_irq_handler(struct drm_i915_private *dev_priv, static u32 i9xx_hpd_irq_ack(struct drm_i915_private *dev_priv) { - u32 hotplug_status = I915_READ(PORT_HOTPLUG_STAT); + u32 hotplug_status = 0, hotplug_status_mask; + int i; + + if (IS_G4X(dev_priv) || + IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) + hotplug_status_mask = HOTPLUG_INT_STATUS_G4X | + DP_AUX_CHANNEL_MASK_INT_STATUS_G4X; + else + hotplug_status_mask = HOTPLUG_INT_STATUS_I915; - if (hotplug_status) + /* + * We absolutely have to clear all the pending interrupt + * bits in PORT_HOTPLUG_STAT. Otherwise the ISR port + * interrupt bit won't have an edge, and the i965/g4x + * edge triggered IIR will not notice that an interrupt + * is still pending. We can't use PORT_HOTPLUG_EN to + * guarantee the edge as the act of toggling the enable + * bits can itself generate a new hotplug interrupt :( + */ + for (i = 0; i < 10; i++) { + u32 tmp = I915_READ(PORT_HOTPLUG_STAT) & hotplug_status_mask; + + if (tmp == 0) + return hotplug_status; + + hotplug_status |= tmp; I915_WRITE(PORT_HOTPLUG_STAT, hotplug_status); + } + + WARN_ONCE(1, + "PORT_HOTPLUG_STAT did not clear (0x%08x)\n", + I915_READ(PORT_HOTPLUG_STAT)); return hotplug_status; }