[PATCH] drm/bochs: convert bochs driver to atomic mode-setting

[Gerd Hoffmann]

On Do, 2015-06-11 at 11:18 +0800, John Hunter wrote:
> Hi Gerd,
> Here is what I got:
> 
> 
> [  813.137939] [drm:drm_pci_init] 
> [  813.142780] [drm:drm_get_pci_dev] 
> [  813.156986] [drm:drm_minor_register] 
> [  813.212679] [drm:drm_minor_register] new minor registered 64
> [  813.213341] [drm:drm_minor_register] 
> [  813.215081] [drm:drm_minor_register] 
> [  813.235736] [drm:drm_minor_register] new minor registered 0
> [  813.252701] [drm] Found bochs VGA, ID 0xb0c0.
> [  813.254993] [drm] Framebuffer size 8192 kB @ 0xfe000000, ioports @
> 0x1ce.
> [  813.271384] [TTM] Zone  kernel: Available graphics memory: 513150
> kiB
> [  813.272036] [TTM] Initializing pool allocator
> [  813.279538] [TTM] Initializing DMA pool allocator
> [  813.299800] [drm:drm_sysfs_connector_add] adding "Virtual-1" to
> sysfs
> [  813.303164] [drm:drm_sysfs_hotplug_event] generating hotplug event
> [  813.313079] [drm] Initialized bochs-drm 1.0.0 20130925 for
> 0000:00:02.0 on minor 0

Looks good.

> If I remove the bochs-drm.ko from its place, then boot the virtual
> machine, after it runs,
> copy the bochs-drm.ko to its original place, depmod the module, and
> modprobe 
> bochs-drm, it give the messages above. Seems like the bochs driver
> works, but
> if I reboot with the bochs-drm.ko, it goes to dark, and the messages
> related to bochs
> is same as above.

Hmm, behavior should be the same no matter whenever it is loaded
automatically at boot time or manually later on.

You can blacklist the module in modprobe.conf if you want prevent it
from autoloading btw.

> I guess the problem is because that I take no care of bochs_hw_setbase
> after remove
> the bochs_crtc_mode_set_base, but I am not sure. 

Possibly, programming the hardware needs to happen at some point ...
Stick a printk in there to see whenever it is called or not.

But remember you don't have a framebuffer console because fbcon is
turned off.  So not having VTs is normal (and thats why you need the
serial console ...)

What happens if you start X?

> I will be appreciate if you can review the patch a bit and tell me
> where the problem
> might be, and I will dig more into that.

Well, it's your gsoc project, not mine.

cheers,
  Gerd