From patchwork Thu Jun 19 09:53:51 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiejun Chen X-Patchwork-Id: 361828 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id C8D20140084 for ; Thu, 19 Jun 2014 19:55:58 +1000 (EST) Received: from localhost ([::1]:34575 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WxZ4X-0001vm-4s for incoming@patchwork.ozlabs.org; Thu, 19 Jun 2014 05:55:57 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51056) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WxZ4E-0001fC-Fe for qemu-devel@nongnu.org; Thu, 19 Jun 2014 05:55:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WxZ47-0000at-Pu for qemu-devel@nongnu.org; Thu, 19 Jun 2014 05:55:38 -0400 Received: from mga01.intel.com ([192.55.52.88]:59175) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WxZ47-0000aM-Ks for qemu-devel@nongnu.org; Thu, 19 Jun 2014 05:55:31 -0400 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 19 Jun 2014 02:55:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,506,1400050800"; d="scan'208";a="557874894" Received: from tchen0-linux.bj.intel.com ([10.238.154.58]) by fmsmga002.fm.intel.com with ESMTP; 19 Jun 2014 02:55:27 -0700 From: Tiejun Chen To: daniel.vetter@ffwll.ch, jani.nikula@linux.intel.com, airlied@linux.ie Date: Thu, 19 Jun 2014 17:53:51 +0800 Message-Id: <1403171631-3452-1-git-send-email-tiejun.chen@intel.com> X-Mailer: git-send-email 1.9.1 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.88 Cc: intel-gfx@lists.freedesktop.org, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, qemu-devel@nongnu.org Subject: [Qemu-devel] [RFC][PATCH] gpu:drm:i915:intel_detect_pch: back to check devfn instead of check class type X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Originally the reason to probe ISA bridge instead of Dev31:Fun0 is to make graphics device passthrough work easy for VMM, that only need to expose ISA bridge to let driver know the real hardware underneath. This is a requirement from virtualization team. Especially in that virtualized environments, XEN, there is irrelevant ISA bridge in the system with that legacy qemu version specific to xen, qemu-xen-traditional. So to work reliably, we should scan through all the ISA bridge devices and check for the first match, instead of only checking the first one. But actually, qemu-xen-traditional, is always enumerated with Dev31:Fun0, 00:1f.0 as follows: hw/pt-graphics.c: intel_pch_init() | + pci_isa_bridge_init(bus, PCI_DEVFN(0x1f, 0), ...); so this mean that isa bridge is still represented with Dev31:Func0 like the native OS. Furthermore, currently we're pushing VGA passthrough support into qemu upstream, and with some discussion, we wouldn't set the bridge class type and just expose this devfn. So we just go back to check devfn to make life normal. Signed-off-by: Tiejun Chen Reviewed-by: Zhenyu Wang --- drivers/gpu/drm/i915/i915_drv.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 651e65e..cb2526e 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -417,18 +417,8 @@ void intel_detect_pch(struct drm_device *dev) return; } - /* - * The reason to probe ISA bridge instead of Dev31:Fun0 is to - * make graphics device passthrough work easy for VMM, that only - * need to expose ISA bridge to let driver know the real hardware - * underneath. This is a requirement from virtualization team. - * - * In some virtualized environments (e.g. XEN), there is irrelevant - * ISA bridge in the system. To work reliably, we should scan trhough - * all the ISA bridge devices and check for the first match, instead - * of only checking the first one. - */ - while ((pch = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, pch))) { + pch = pci_get_bus_and_slot(0, PCI_DEVFN(0x1f, 0)); + if (pch) { if (pch->vendor == PCI_VENDOR_ID_INTEL) { unsigned short id = pch->device & INTEL_PCH_DEVICE_ID_MASK; dev_priv->pch_id = id; @@ -462,10 +452,7 @@ void intel_detect_pch(struct drm_device *dev) DRM_DEBUG_KMS("Found LynxPoint LP PCH\n"); WARN_ON(!IS_HASWELL(dev)); WARN_ON(!IS_ULT(dev)); - } else - continue; - - break; + } } } if (!pch)