Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753802Ab1FOUIy (ORCPT ); Wed, 15 Jun 2011 16:08:54 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:35734 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752937Ab1FOUIw (ORCPT ); Wed, 15 Jun 2011 16:08:52 -0400 Date: Wed, 15 Jun 2011 16:08:51 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Keith Packard cc: dri-devel@lists.freedesktop.org, Kernel development list Subject: Re: Oops in i915 intel_init_clock_gating Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4516 Lines: 101 The problem of dev_priv->display.init_clock_gating not getting set is still present in 3.0-rc3. On my system this happens because intel_init_display() never gets called in the first place. AFAICT, the normal calling sequence during driver initialization is: i915_driver_load() -> i915_load_modeset_init() -> intel_modeset_init() -> intel_init_display(). But in my case the call to i915_load_modeset_init() doesn't occur because drm_core_check_feature(dev, DRIVER_MODESET) is False. I tested with the following patch: Index: usb-3.0/drivers/gpu/drm/i915/intel_display.c =================================================================== --- usb-3.0.orig/drivers/gpu/drm/i915/intel_display.c +++ usb-3.0/drivers/gpu/drm/i915/intel_display.c @@ -7511,6 +7511,10 @@ void intel_init_clock_gating(struct drm_ { struct drm_i915_private *dev_priv = dev->dev_private; + if (!dev_priv->display.init_clock_gating) { + printk(KERN_WARNING "init_clock_gating not set!\n"); + WARN_ON(1); + } else dev_priv->display.init_clock_gating(dev); if (dev_priv->display.init_pch_clock_gating) Index: usb-3.0/drivers/gpu/drm/i915/i915_dma.c =================================================================== --- usb-3.0.orig/drivers/gpu/drm/i915/i915_dma.c +++ usb-3.0/drivers/gpu/drm/i915/i915_dma.c @@ -2078,7 +2078,9 @@ int i915_driver_load(struct drm_device * intel_detect_pch(dev); +printk(KERN_INFO "Testing drm_core_check_feature DRIVER_MODESET\n"); if (drm_core_check_feature(dev, DRIVER_MODESET)) { +printk(KERN_INFO "Calling i915_load_modeset_init\n"); ret = i915_load_modeset_init(dev); if (ret < 0) { DRM_ERROR("failed to init modeset\n"); Here is the dmesg log showing what happens during "insmod i915.ko": [ 908.129497] pci 0000:00:02.0: setting latency timer to 64 [ 908.179865] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010). [ 908.180633] [drm] No driver support for vblank timestamp query. [ 908.180804] Testing drm_core_check_feature DRIVER_MODESET [ 908.181120] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0 The first debugging message is printed but not the second. Here is what happens during a resume from system suspend: [ 943.013656] init_clock_gating not set! [ 943.013790] ------------[ cut here ]------------ [ 943.013954] WARNING: at drivers/gpu/drm/i915/intel_display.c:7516 intel_init_clock_gating+0x30/0x4a [i915]() [ 943.014193] Hardware name: HP dx2000 MT (EE004AA) [ 943.014330] Modules linked in: i915 fbcon font bitblit softcursor drm_kms_helper drm fb fbdev i2c_algo_bit cfbcopyarea i2c_core video backlight cfbimgblt cfbfillrect e100 ohci_hcd mii pcspkr evdev uhci_hcd ehci_hcd fan processor thermal_sys button usbcore [last unloaded: i915] [ 943.015825] Pid: 1678, comm: bash Not tainted 3.0.0-rc3 #2 [ 943.015966] Call Trace: [ 943.016179] [] warn_slowpath_common+0x65/0x7a [ 943.016342] [] ? intel_init_clock_gating+0x30/0x4a [i915] [ 943.016487] [] warn_slowpath_null+0xf/0x13 [ 943.016644] [] intel_init_clock_gating+0x30/0x4a [i915] [ 943.016801] [] i915_restore_state+0xf4/0x1bf [i915] [ 943.016989] [] i915_drm_thaw+0x41/0xc1 [i915] [ 943.017141] [] i915_resume+0x38/0x4b [i915] [ 943.017301] [] drm_class_resume+0x39/0x3b [drm] [ 943.017447] [] legacy_resume+0x1e/0x46 [ 943.017599] [] ? drm_class_suspend+0x3d/0x3d [drm] [ 943.017742] [] device_resume+0x83/0xa0 [ 943.017881] [] dpm_resume+0xdc/0x156 [ 943.018020] [] dpm_resume_end+0xb/0x15 [ 943.018162] [] suspend_devices_and_enter+0x165/0x192 [ 943.018330] [] enter_state+0xd2/0x123 [ 943.018471] [] state_store+0x95/0xa1 [ 943.018610] [] ? pm_async_store+0x33/0x33 [ 943.018752] [] kobj_attr_store+0x16/0x22 [ 943.018894] [] sysfs_write_file+0xb3/0xec [ 943.019034] [] ? sysfs_open_file+0x1c2/0x1c2 [ 943.019176] [] vfs_write+0x76/0xa2 [ 943.019315] [] sys_write+0x3b/0x5d [ 943.019456] [] sysenter_do_call+0x12/0x36 [ 943.019625] ---[ end trace dc74bd86a8bff7da ]--- What's the right way to fix this? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/