Re: [PATCH] 50drm: Install dracut 50drm module in hostonly mode when drm driver is currently in use.

[Harald Hoyer <harald-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On 05/29/2013 04:45 AM, Dave Young wrote:
> On 05/28/2013 08:09 PM, Harald Hoyer wrote:
>> On 05/24/2013 10:22 AM, WANG Chao wrote:
>>> Now only 50plymouth module can pull in 50drm and that's very limited.
>>> Because KMS capable drm drivers are much needed in initrd to have a
>>> frame buffer console on the screen.
>>>
>>> Particularly, when building kdump initrd, plymouth module is omitted,
>>> but drm is necessary to setup a working screen for one sitting in front
>>> of a monitor.
>>>
>>> Signed-off-by: WANG Chao <chaowang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>>> ---
>>>  modules.d/50drm/module-setup.sh | 4 ++++
>>>  1 file changed, 4 insertions(+)
>>>
>>> diff --git a/modules.d/50drm/module-setup.sh b/modules.d/50drm/module-setup.sh
>>> index bf33c5b..648e8f4 100644
>>> --- a/modules.d/50drm/module-setup.sh
>>> +++ b/modules.d/50drm/module-setup.sh
>>> @@ -3,6 +3,10 @@
>>>  # ex: ts=8 sw=4 sts=4 et filetype=sh
>>>  
>>>  check() {
>>> +    if [[ $hostonly ]] && [ -d /sys/module/drm/drivers ]; then
>>> +        return 0
>>> +    fi
>>> +
>>>      return 255
>>>  }
>>>  
>>>
>>
>> Hmm, why not let the kdump module depend on drm?
> 
> If you do not like it we can consider add it to kdump module..
> 
>>
>> depends() {
>>     echo drm
>> }
>>
>> Anyway, do we really need drm for a simple console? Those drivers are really
>> really big and take a long time to load and initialize?
> 
> It's a little awkward, after kernel crashing suppose 1st kernel is in
> kms mode, it can not reset to nomodeset, so screen will keep black.
> 
> There's no such issue in normal initramfs because bios always reset
> devices for us.
> 

Ah! Thanks for the clarification! That makes sense. Because this happens only
for kexec, I suggest to add the dependency to the kdump module.