Bug 99655

Summary:	i915 warning: WARN_ON_ONCE(!intel_dp->lane_count)
Product:	DRI	Reporter:	Manasi <manasi.d.navare>
Component:	DRM/Intel	Assignee:	Manasi <manasi.d.navare>
Status:	CLOSED DUPLICATE	QA Contact:	Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity:	normal
Priority:	medium	CC:	intel-gfx-bugs, manasi.d.navare
Version:	DRI git
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:	SKL	i915 features:	display/DP

Description Manasi 2017-02-02 19:14:36 UTC

[drm] Initialized i915 1.6.0 20161121 for 0000:00:02.0 on minor 0
> >   ------------[ cut here ]------------
> >   WARNING: CPU: 1 PID: 130 at drivers/gpu/drm/i915/intel_dp.c:4018
> > intel_dp_check_link_status+0x1db$
> >   WARN_ON_ONCE(!intel_dp->lane_count)
> >   Modules linked in:
> >    rtsx_pci_sdmmc mmc_core crct10dif_pclmul crc32_pclmul 
> > crc32c_intel
> > i915 ghash_clmulni_intel i2c_$
> >   CPU: 1 PID: 130 Comm: kworker/u8:7 Not tainted
> > 4.9.0-04822-g9439b3710df6
> > #6
> >   Hardware name: Dell Inc. XPS 13 9350/09JHRY, BIOS 1.4.4 06/14/2016
> >   Workqueue: events_unbound async_run_entry_fn
> >   Call Trace:
> >    intel_dp_check_link_status+0x1db/0x200 [i915]
> >    intel_dp_detect+0x697/0xa40 [i915]
> >    drm_helper_probe_single_connector_modes+0x2a3/0x500
> [drm_kms_helper]
> >    drm_setup_crtcs+0x7b/0x9c0 [drm_kms_helper]
> >    drm_fb_helper_initial_config+0x79/0x3e0 [drm_kms_helper]
> >    intel_fbdev_initial_config+0x18/0x30 [i915]
> >    async_run_entry_fn+0x37/0x150
> >    process_one_work+0x1f1/0x480
> >    worker_thread+0x48/0x4d0
> >    kthread+0x101/0x140
> >    ret_from_fork+0x22/0x30
> >   ---[ end trace 10162024459bbe32 ]---

Bug pointed out by Linus, there is a work around added by Daniel Vetter but this needs to be fixed.

Comment 1 Manasi 2017-03-30 20:14:03 UTC

This ahs been fixed, warning not seen on connected boot case any more.

Comment 2 Chris Wilson 2017-03-30 21:44:59 UTC


*** This bug has been marked as a duplicate of bug 98374 ***

Comment 3 Manasi 2017-04-27 23:52:37 UTC

This is fixed now since the WARN_ON was changed to a conditional check and return. The fix has been merged.
So I am changing the status to resolve for now.

Manasi

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