[PATCH] drm/vmwgfx: respect 'nomodeset'

[Rob Clark]

On Wed, Oct 15, 2014 at 4:17 PM, Thomas Hellstrom <thellstrom at vmware.com> wrote:
> On 10/15/2014 09:46 PM, Rob Clark wrote:
>> On Wed, Oct 15, 2014 at 3:24 PM, Thomas Hellstrom <thellstrom at vmware.com> wrote:
>>> On 10/15/2014 09:00 PM, Rob Clark wrote:
>>>> Signed-off-by: Rob Clark <robdclark at gmail.com>
>>>> ---
>>>>  drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 7 +++++++
>>>>  1 file changed, 7 insertions(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
>>>> index 18b54ac..f0267b8 100644
>>>> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
>>>> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
>>>> @@ -25,6 +25,7 @@
>>>>   *
>>>>   **************************************************************************/
>>>>  #include <linux/module.h>
>>>> +#include <linux/console.h>
>>>>
>>>>  #include <drm/drmP.h>
>>>>  #include "vmwgfx_drv.h"
>>>> @@ -1453,6 +1454,12 @@ static int vmw_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>>>>  static int __init vmwgfx_init(void)
>>>>  {
>>>>       int ret;
>>>> +
>>>> +#ifdef CONFIG_VGA_CONSOLE
>>>> +     if (vgacon_text_force())
>>>> +             return -EINVAL;
>>>> +#endif
>>>> +
>>> Hmm,
>>>
>>> From the function name vgacon_text_force() it sounds like this should
>>> just stop the driver from initializing fbcon? Not refuse to load?
>> yeah, the function is badly named.. it perhaps should be
>> vgacon_is_text_forced() or something like that.  But basically it
>> returns whether we are forced to text mode.
>>
>> BR,
>> -R
>
> So then I guess it would be more correct to use the output of that
> function when determining the value of dev_priv->enable_fb (vmwgfx can
> enable the user-space modesetting API without turning on vmwgfx fbcon).

well, other drivers, 'nomodeset' forces the driver not to load (to
work around buggyness, etc)..  I suppose for vmwgfx perhaps oddball
"hardware" is less of a concern.  Although it seems like it would be
nice if vmwgfx behaved consistently with the other drivers.

Most/all for the drivers have an additional module param that lets you
override this and load the driver for UMS in case of 'nomodeset'..
which would give you the behaviour you describe.  But I think in the
absence of an additional module param specified, the default
'nomodeset' behaviour should be that the driver does not load.

But I can add such a module param if you think it is useful..

BR,
-R

> /Thomas
>