[Intel-gfx] More questions and patches for 835GM/ns2501 DVO

[Thomas Richter]

On 03.11.2013 18:13, Daniel Vetter wrote:
>> Have you tried my patch to reorder the dvo sequence a bit? That /should/
>> get all these things right:
>>
>> http://www.spinics.net/lists/intel-gfx/msg34349.html
> There's also a follow-up patch for you to test:
>
> http://www.spinics.net/lists/intel-gfx/msg34350.html
>
> That would prove that the first patch does indeed work. Note that patch 1
> in this series is already merged.
Thanks, I tried. Actually, this worked fairly (but not perfectly) well. 
I no longer get a "stuck DVO" as I did before, i.e. the "re-enable" 
logic is not triggered anymore. However, I do get (occasionally) a 
kernel-oops:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 2311 at drivers/gpu/drm/i915/intel_display.c:1098 
assert_cursor.constprop.68+0xba/0xc0 [i915]()
cursor on pipe A assertion failure (expected off, current on)
Modules linked in: cpufreq_stats binfmt_misc michael_mic arc4 ecb 
lib80211_crypt_tkip lib80211_crypt_ccmp fuse nfsd exportfs nfs_acl nfs 
lockd fscache sunrpc loop firewire_sbp2 hostap_cs hostap snd_intel8x0 
snd_ac97_codec ac97_bus lib80211 snd_pcm i915 snd_page_alloc snd_seq 
snd_seq_device snd_timer psmouse snd pcmcia apanel input_polldev 
soundcore yenta_socket pcmcia_rsrc pcmcia_core lpc_ich i2c_i801 mfd_core 
pcspkr i2c_algo_bit rng_core serio_raw evdev drm_kms_helper drm 
fujitsu_laptop led_class intel_agp intel_gtt agpgart i2c_core video ac 
button hid_generic usbhid hid sg sr_mod cdrom firewire_ohci 
firewire_core crc_itu_t 8139too 8139cp mii uhci_hcd usbcore usb_common
CPU: 0 PID: 2311 Comm: Xorg Tainted: G        W    3.12.0-rc7+ #13
Hardware name: FUJITSU SIEMENS LIFEBOOK S Series/FJNB159, BIOS Version 
1.06  07/02/2002
  c12f8c44 c1033def f8ad3990 f6adfab0 00000907 f8ad25d8 0000044a f8a81ffa
  f8a81ffa f5ca8000 00000041 00000000 f5ca8000 c1033eb3 00000009 f6adfa98
  f8ad3990 f6adfab0 f8a81ffa f8ad25d8 0000044a f8ad3990 00000041 f8adb9a0
Call Trace:
  [<c12f8c44>] ? dump_stack+0xa/0x13
  [<c1033def>] ? warn_slowpath_common+0x7f/0xb0
  [<f8a81ffa>] ? assert_cursor.constprop.68+0xba/0xc0 [i915]
  [<f8a81ffa>] ? assert_cursor.constprop.68+0xba/0xc0 [i915]
  [<c1033eb3>] ? warn_slowpath_fmt+0x33/0x40
  [<f8a81ffa>] ? assert_cursor.constprop.68+0xba/0xc0 [i915]
  [<f8a83b90>] ? intel_disable_pipe+0x30/0xb0 [i915]
  [<f8a8491a>] ? i9xx_crtc_disable+0xca/0x2f0 [i915]
  [<f8a8b25e>] ? __intel_set_mode+0x7ae/0x13b0 [i915]
  [<f8a8e1f3>] ? intel_set_mode+0x23/0x40 [i915]
  [<f8a8e9bc>] ? intel_crtc_set_config+0x7ac/0x9d0 [i915]
  [<f802fe33>] ? drm_mode_set_config_internal+0x43/0xb0 [drm]
  [<f81386a5>] ? drm_fb_helper_set_par+0x45/0xac [drm_kms_helper]
  [<c11a7976>] ? fb_set_var+0x1a6/0x420
  [<c10eec6e>] ? __find_get_block+0x9e/0x160
  [<c11b56e0>] ? fbcon_blank+0x290/0x2d0
  [<c1203848>] ? do_unblank_screen+0x98/0x1b0
  [<c1201acd>] ? notify_update+0x1d/0x30
  [<c11faa12>] ? complete_change_console+0x52/0xe0
  [<c11fbba4>] ? vt_ioctl+0x1104/0x1220
  [<f802a1d0>] ? drm_setmaster_ioctl+0xe0/0xe0 [drm]
  [<c11faaa0>] ? complete_change_console+0xe0/0xe0
  [<c11f17da>] ? tty_ioctl+0x21a/0x9a0
  [<c10adb12>] ? do_wp_page.isra.92+0x2a2/0x650
  [<c10af428>] ? handle_mm_fault+0x318/0x610
  [<c11f15c0>] ? no_tty+0x20/0x20
  [<c10d66ac>] ? do_vfs_ioctl+0x7c/0x550
  [<c102d221>] ? __do_page_fault+0x1b1/0x490
  [<c10c7d17>] ? vfs_write+0x137/0x1b0
  [<c10d6bc6>] ? SyS_ioctl+0x46/0x80
  [<c12fc19e>] ? sysenter_do_call+0x12/0x26
---[ end trace 85d231d1072e932a ]---

If this happens, I get a black screen with only a cursor on it. 
Switching to the console and back restores the screen.

I will try how the patch performs with an external monitor on.

BTW, there is a second issue related to this laptop: The vertical 
position of the boot console is sometimes off, and sometimes it is not 
visible at all. Sometimes it is too high (the first line is above the 
first line of the monitor) or too
low (the first line is somewhere in the middle of the screen). Seems to 
me that some of the registers should only
be written to at the vertical blank?

Thanks, however! This is so far definitely an improvement. Will report 
back with the two-monitor setup.

Greetings,
     Thomas