[PATCH] drm/vmwgfx: respect 'nomodeset'

[Rob Clark]

On Wed, Oct 15, 2014 at 4:35 PM, Rob Clark <robdclark at gmail.com> wrote:
> 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..

oh, wait.. you already have an 'enable_fbdev'..  although I guess that
is actually meaning "enable_kms"?

(as opposed to the newer option of having KMS support but no fbdev emulation)

BR,
-R


> BR,
> -R
>
>> /Thomas
>>