2014-04-01 17:52 GMT-03:00 Daniel Vetter <daniel@xxxxxxxx>: > On Tue, Apr 01, 2014 at 05:48:15PM -0300, Paulo Zanoni wrote: >> 2014-04-01 17:37 GMT-03:00 Daniel Vetter <daniel@xxxxxxxx>: >> > On Tue, Apr 01, 2014 at 02:55:09PM -0300, Paulo Zanoni wrote: >> >> From: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> >> >> >> >> ... 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. >> >> >> >> Testcase: igt/pm_pc8 >> >> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> >> > >> > Hm, where's an example backtrace for this? I wonder whether we simply need >> > to extend the range where we hold the runtime pm ref a bit ... >> >> There are tons of WARNs, but here is one example: >> >> [ 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] [<ffffffff8167ec6f>] dump_stack+0x4d/0x66 >> [ 63.664916] [<ffffffff8106c8ed>] warn_slowpath_common+0x7d/0xa0 >> [ 63.664920] [<ffffffff8106c95c>] warn_slowpath_fmt+0x4c/0x50 >> [ 63.664926] [<ffffffff810bd6be>] ? mark_held_locks+0xae/0x130 >> [ 63.664941] [<ffffffffa00d80d2>] >> assert_device_not_suspended.isra.7+0x32/0x40 [i915] >> [ 63.664956] [<ffffffffa00d99d2>] gen6_read32+0x32/0x120 [i915] >> [ 63.664969] [<ffffffffa00d99a0>] ? gen6_read8+0x120/0x120 [i915] >> [ 63.664985] [<ffffffffa0106f8f>] edp_have_panel_vdd+0x3f/0x50 [i915] >> [ 63.665000] [<ffffffffa01074e8>] edp_panel_vdd_off_sync+0x58/0x1c0 [i915] >> [ 63.665004] [<ffffffff8108a06c>] ? process_one_work+0x18c/0x560 >> [ 63.665018] [<ffffffffa0107684>] edp_panel_vdd_work+0x34/0x50 [i915] >> [ 63.665022] [<ffffffff8108a0d7>] process_one_work+0x1f7/0x560 >> [ 63.665026] [<ffffffff8108a06c>] ? process_one_work+0x18c/0x560 >> [ 63.665031] [<ffffffff8108ae2b>] worker_thread+0x11b/0x3a0 > > Ah, that's the async edp worker thread. I guess we need to grab a runtim > pm ref when we start it and drop it again in the worker instead? IMHO it doesn't make sense to keep the HW awake just so we can read a register to find out things are disabled, so I prefer the current solution. If we want a "better" solution, IMHO we should track the sate of the VDD in software, like intel_dp->has_panel_vdd. This would avoid many more register reads. > > I'll add the backtrace to the commit, thanks. > -Daniel > >> [ 63.665035] [<ffffffff8108ad10>] ? manage_workers.isra.21+0x2a0/0x2a0 >> [ 63.665039] [<ffffffff810916fc>] kthread+0xfc/0x120 >> [ 63.665043] [<ffffffff81091600>] ? kthread_create_on_node+0x230/0x230 >> [ 63.665048] [<ffffffff8169082c>] ret_from_fork+0x7c/0xb0 >> [ 63.665052] [<ffffffff81091600>] ? 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 ]------------ >> >> > >> > Whatever, merged (I can rebase afterwards if you supply the backtrace for >> > the commit message, there we should at least have it). >> > -Daniel >> >> --- >> >> 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 6f767e5..44471cc 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 >> >> -- >> >> 1.8.5.3 >> >> >> >> _______________________________________________ >> >> Intel-gfx mailing list >> >> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx >> >> http://lists.freedesktop.org/mailman/listinfo/intel-gfx >> > >> > -- >> > Daniel Vetter >> > Software Engineer, Intel Corporation >> > +41 (0) 79 365 57 48 - http://blog.ffwll.ch >> >> >> >> -- >> Paulo Zanoni > > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- Paulo Zanoni _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx