From efbc20abd826033859cc28d1442e48640cf09045 Mon Sep 17 00:00:00 2001 From: Paulo Zanoni Date: Tue, 1 Apr 2014 14:55:09 -0300 Subject: [PATCH] drm/i915: don't read pp_ctrl_reg if we're suspended ... at edp_have_panel_vdd. Just return false, saying we don't have the panel VDD since the device is suspended. We started getting WARNs about this problem since the patch that started checking if we're suspended while reading registers. Example backtrace provided by Paulo: [ 63.572201] [drm:hsw_enable_pc8] Enabling package C8+ [ 63.581831] [drm:i915_runtime_suspend] Device suspended [ 63.664798] ------------[ cut here ]------------ [ 63.664824] WARNING: CPU: 3 PID: 828 at drivers/gpu/drm/i915/intel_uncore.c:47 assert_device_not_suspended.isra.7+0x32/0x40 [i915]() [ 63.664826] Device suspended [ 63.664828] Modules linked in: ccm fuse ip6table_filter ip6_tables ebtable_nat ebtables arc4 ath9k_htc ath9k_common ath9k_hw mac80211 ath cfg80211 iTCO_wdt iTCO_vendor_support x86_pkg_temp_thermal coretemp microcode i2c_i801 e1000e pcspkr serio_raw lpc_ich ptp pps_core mei_me mei mfd_core dm_crypt i915 crc32_pclmul crc32c_intel ghash_clmulni_intel i2c_algo_bit drm_kms_helper drm video [ 63.664867] CPU: 3 PID: 828 Comm: kworker/3:3 Not tainted 3.14.0+ #153 [ 63.664869] Hardware name: Intel Corporation Shark Bay Client platform/WhiteTip Mountain 1, BIOS HSWLPTU1.86C.0133.R00.1309172123 09/17/2013 [ 63.664887] Workqueue: events edp_panel_vdd_work [i915] [ 63.664889] 0000000000000009 ffff88009d745c28 ffffffff8167ec6f ffff88009d745c70 [ 63.664895] ffff88009d745c60 ffffffff8106c8ed ffff880036278000 00000000000c7204 [ 63.664900] ffff88014f2d3040 ffff880036278070 0000000000000001 ffff88009d745cc0 [ 63.664905] Call Trace: [ 63.664911] [] dump_stack+0x4d/0x66 [ 63.664916] [] warn_slowpath_common+0x7d/0xa0 [ 63.664920] [] warn_slowpath_fmt+0x4c/0x50 [ 63.664926] [] ? mark_held_locks+0xae/0x130 [ 63.664941] [] assert_device_not_suspended.isra.7+0x32/0x40 [i915] [ 63.664956] [] gen6_read32+0x32/0x120 [i915] [ 63.664969] [] ? gen6_read8+0x120/0x120 [i915] [ 63.664985] [] edp_have_panel_vdd+0x3f/0x50 [i915] [ 63.665000] [] edp_panel_vdd_off_sync+0x58/0x1c0 [i915] [ 63.665004] [] ? process_one_work+0x18c/0x560 [ 63.665018] [] edp_panel_vdd_work+0x34/0x50 [i915] [ 63.665022] [] process_one_work+0x1f7/0x560 [ 63.665026] [] ? process_one_work+0x18c/0x560 [ 63.665031] [] worker_thread+0x11b/0x3a0 [ 63.665035] [] ? manage_workers.isra.21+0x2a0/0x2a0 [ 63.665039] [] kthread+0xfc/0x120 [ 63.665043] [] ? kthread_create_on_node+0x230/0x230 [ 63.665048] [] ret_from_fork+0x7c/0xb0 [ 63.665052] [] ? kthread_create_on_node+0x230/0x230 [ 63.665054] ---[ end trace 1250bcc890af9999 ]--- [ 63.665060] [drm:edp_panel_vdd_off_sync] Turning eDP VDD off [ 63.665061] ------------[ cut here ]------------ Testcase: igt/pm_pc8 Signed-off-by: Paulo Zanoni Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 6f767e522b3f..44471ccdc385 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -314,7 +314,8 @@ static bool edp_have_panel_vdd(struct intel_dp *intel_dp) struct drm_device *dev = intel_dp_to_dev(intel_dp); struct drm_i915_private *dev_priv = dev->dev_private; - return (I915_READ(_pp_ctrl_reg(intel_dp)) & EDP_FORCE_VDD) != 0; + return !dev_priv->pm.suspended && + (I915_READ(_pp_ctrl_reg(intel_dp)) & EDP_FORCE_VDD) != 0; } static void -- 2.30.2