[Intel-gfx] Regression in i915 driver in 3.16-rc2

[Alan Stern]

On Wed, 25 Jun 2014, Ville [iso-8859-1] Syrjälä wrote:

> On Wed, Jun 25, 2014 at 02:06:55PM -0400, Alan Stern wrote:
> > Daniel:
> > 
> > I encountered a new problem in the i915 driver the first time I booted 
> > a 3.16-rc kernel on this computer.  When it switched over to the frame 
> > buffer driver, the screen went blank and stayed that way.
> > 
> > 3.15 works okay.
> > 
> > Attached are log extracts from 3.15 and 3.16 (both with drm.debug=0xe
> > in the boot command line).  The timestamps have been stripped out for
> > easy diff comparison.  These are the result of
> > 
> > 	dmesg | egrep 'drm|i915|frame'
> > 
> > with a couple of irrelevant lines removed.  I can send the complete 
> > logs if you need them.
> > 
> > Alan Stern
> 
> > Kernel command line: BOOT_IMAGE=/boot/test-3.x root=/dev/hda8 ro console=ttyS0,115200 console=tty0 earlyprintk=serial,ttyS0,115200 no_console_suspend drm.debug=0xe vconsole.keymap=us vconsole.font=latarcyrheb-sun16 LANG=en_US.UTF-8 usbcore.dyndbg=+p ehci_hcd.dyndbg=+p
> > [drm] Initialized drm 1.1.0 20060810
> > [drm:i915_dump_device_info] i915 device info: gen=2, pciid=0x2572 flags=has_overlay,overlay_needs_physical,
> > [drm:intel_detect_pch] No PCH found.
> > [drm] Memory usable by graphics device = 128M
> > [drm:i915_gem_gtt_init] GMADR size = 128M
> > [drm:i915_gem_gtt_init] GTT stolen size = 8M
> > [drm:i915_gem_gtt_init] ppgtt mode: 0
> > [drm:intel_opregion_setup] graphic opregion physical addr: 0x0
> > [drm:intel_opregion_setup] ACPI OpRegion not supported!
> > [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
> > [drm] Driver supports precise vblank timestamp query.
> > [drm:init_vbt_defaults] Set default to SSC at 66667 kHz
> > [drm:parse_general_features] BDB_GENERAL_FEATURES int_tv_support 1 int_crt_support 0 lvds_use_ssc 0 lvds_ssc_freq 48000 display_clock_mode 0 fdi_rx_polarity_inverted 0
>                                                                      ^^^^^^^^^^^^^^^^^
> 
> This should get your display back:
> http://patchwork.freedesktop.org/patch/28508/

It did indeed.  Thank you very much.

Alan Stern