Bug 105261

Summary:	Regression in "Broadcast RGB" behavior of Intel driver
Product:	Drivers	Reporter:	Rob Hasselbaum (rob)
Component:	Video(DRI - Intel)	Assignee:	intel-gfx-bugs (intel-gfx-bugs)
Status:	RESOLVED MOVED
Severity:	normal	CC:	intel-gfx-bugs, michael.letzgus
Priority:	P1
Hardware:	All
OS:	Linux
URL:	https://bugs.freedesktop.org/show_bug.cgi?id=92206
Kernel Version:	4.2.1	Subsystem:
Regression:	No	Bisected commit-id:

Description Rob Hasselbaum 2015-09-30 01:01:23 UTC

In kernel 4.1.6 and earlier, colors look washed out on my LCD monitor unless I set "Broadcast RGB" to "Full" in my xprofile like so:

xrandr --output HDMI1 --set "Broadcast RGB" "Full"

When upgrading from kernel 4.1.6 -> 4.2.1, this setting no longer works and colors are washed out. Downgrading back to 4.1.6 works around the problem. I also see the following repeated kernel error in the log with 4.2.1:

[drm:check_crtc_state [i915]] *ERROR* mismatch in limited_color_range (expected 0, found 1)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8262 at drivers/gpu/drm/i915/intel_display.c:12324 check_crtc_state+0x8df/0xf80 [i915]()
pipe state doesn't match!
Modules linked in: fuse nfnetlink_queue nfnetlink_log nfnetlink bluetooth bbswitch(O) ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 uvcvideo videobu
 rfkill mii kvm_intel i915 drm_kms_helper drm intel_gtt mei_me mei shpchp i2c_algo_bit i2c_i801 lpc_ich snd_hda_intel snd_hda_codec snd_hda_c
 atkbd libps2 ahci libahci crct10dif_pclmul crc32_pclmul xhci_pci crc32c_intel ehci_pci ghash_clmulni_intel xhci_hcd libata ehci_hcd aesni_in
CPU: 0 PID: 8262 Comm: Xorg Tainted: G        W  O    4.2.1-1-ARCH #1
Hardware name: Hewlett-Packard HP Pavilion dv7 Notebook PC/181F, BIOS F.0B 06/19/2012
 0000000000000000 00000000ab424e4b ffff8802c62e7468 ffffffff8156b77a
 0000000000000000 ffff8802c62e74c0 ffff8802c62e74a8 ffffffff81074846
 00000001c62e74d8 ffff88034de5d350 ffff880095f05000 ffff88034de5d000
Call Trace:
 [<ffffffff8156b77a>] dump_stack+0x4c/0x6e
 [<ffffffff81074846>] warn_slowpath_common+0x86/0xc0
 [<ffffffff810748d5>] warn_slowpath_fmt+0x55/0x70
 [<ffffffffa07cdf7f>] check_crtc_state+0x8df/0xf80 [i915]
 [<ffffffffa07e09f6>] intel_modeset_check_state+0x216/0xb50 [i915]
 [<ffffffffa07db00c>] ? __intel_set_mode+0x92c/0xb60 [i915]
 [<ffffffffa07e2037>] intel_crtc_set_config+0x4c7/0x580 [i915]
 [<ffffffffa06ea9f6>] drm_mode_set_config_internal+0x66/0x100 [drm]
 [<ffffffffa0750552>] restore_fbdev_mode+0xc2/0xf0 [drm_kms_helper]
 [<ffffffffa07524b9>] drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x70 [drm_kms_helper]
 [<ffffffffa0752522>] drm_fb_helper_set_par+0x22/0x40 [drm_kms_helper]
 [<ffffffffa07f06ca>] intel_fbdev_set_par+0x1a/0x60 [i915]
 [<ffffffff81328cb6>] fb_set_var+0x236/0x460
 [<ffffffff81160d5c>] ? __alloc_pages_nodemask+0x17c/0x960
 [<ffffffffa07c14ad>] ? gen6_read32+0xdd/0x1a0 [i915]
 [<ffffffff8131f8a2>] fbcon_blank+0x312/0x360
 [<ffffffff81399b33>] do_unblank_screen+0xc3/0x190
 [<ffffffff8138feea>] vt_ioctl+0x50a/0x12e0
 [<ffffffff811dd71e>] ? path_parentat+0x3e/0x80
 [<ffffffff81384085>] tty_ioctl+0x3b5/0xba0
 [<ffffffff810d64e7>] ? call_rcu+0x17/0x20
 [<ffffffff813cadf3>] ? vga_arb_release+0xe3/0x130
 [<ffffffff811e29b5>] do_vfs_ioctl+0x295/0x480
 [<ffffffff811ef894>] ? mntput+0x24/0x40
 [<ffffffff811ecaa7>] ? __fget+0x77/0xb0
 [<ffffffff811e2c19>] SyS_ioctl+0x79/0x90
 [<ffffffff81570cee>] entry_SYSCALL_64_fastpath+0x12/0x71
---[ end trace 3ca0f09428c0569c ]---

Comment 1 Jani Nikula 2015-10-01 08:26:52 UTC

Tracked at https://bugs.freedesktop.org/show_bug.cgi?id=92206