ACK: Re: [Disco] Re-enable DRM Support for bochs (qemu stdvga)

[Thomas Lamprecht]

On 3/29/19 4:12 PM, Timo Aaltonen wrote:
> On 29.3.2019 17.04, Timo Aaltonen wrote:
>> On 29.3.2019 16.35, Thomas Lamprecht wrote:
>>> BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1795857
>>>
>>> [Impact]
>>> Booting a Ubuntu with Cosmic kernel inside a QEMU VM with 'stdvga' as display
>>> hangs on gdm unit, display stays black with a single shell cursor blinking in
>>> the upper edge. If switching same VM to another display tipe (e.g., qxl) allows
>>> it to boot just fine.
>>>
>>> [Fix]
>>> Re-enable the DRM_BOCHS driver to be build as module.
>>>
>>> [Test Case]
>>> Start an installed Ubuntu 19.04 (e.g., from Beta or weekly built ISOs) inside a
>>> VM with display 'stdvga'. The installer itself will work, but once you reboot
>>> you get a broken system. With this patch _and_ the 'blacklist bochs-drm' entry
>>> from 'kmod' package shipped '/etc/modprobe.d/blacklist-framebuffer.conf' removed
>>> the system boots as expected, gdm can startup and one can login through a
>>> graphical session
>>>
>>> [Regression Potential]
>>> Low. Even the original bug report pondered if it would be better to fix
>>> bochs-drm instead of plain disabling it. I could not relate to it, but I do not
>>> have PowerPC hardware to test it. I still mark regression potential low as the
>>> driver can get simply blacklisted for cases it isn't wanted or makes problems.
>>>
>>>
>>> Thomas Lamprecht (1):
>>>   UBUNTU: [Config] Reenable DRM_BOCHS as module
>>>
>>>  debian.master/config/annotations | 3 +--
>>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> Hi, I sent a patch for this last year, and bochs was finally recently
>> tested to work fine on ppc64el. Doesn't matter which one actually is
>> applied, but at least your explanation is more verbose, so ACK.
> 
> actually, I think my patch was more complete, it had this hunk too:
> 
> diff --git a/debian.master/config/config.common.ubuntu
> b/debian.master/config/config.common.ubuntu
> index bdece4b92c89..e6e1f5d34ea1 100644
> --- a/debian.master/config/config.common.ubuntu
> +++ b/debian.master/config/config.common.ubuntu
> @@ -2315,7 +2315,7 @@ CONFIG_DRM_ARM=y
>  CONFIG_DRM_ARMADA=m
>  CONFIG_DRM_AST=m
>  CONFIG_DRM_ATMEL_HLCDC=m
> -# CONFIG_DRM_BOCHS is not set
> +CONFIG_DRM_BOCHS=m
>  CONFIG_DRM_BRIDGE=y
>  CONFIG_DRM_CDNS_DSI=m
>  CONFIG_DRM_CIRRUS_QEMU=m
> 
> 

ah yeah sure, forgot to apply this one -.- I'm fine either, I can also resend it,
with a Co-developed-by tag if you do not have time to rebase yours?

Just happy if this works once Disco is released :)