[PATCH] drm/msm: kick out firmware framebuffer

[Rob Clark]

On Mon, Jul 3, 2017 at 1:02 PM, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Mon, Jul 03, 2017 at 11:56:23AM -0400, Rob Clark wrote:
>> Fixes a problem with console not appearing when booting with EFI that
>> has GOP support, because fb0 would end up being efifb, even after drm
>> has taken over the display.
>>
>> Signed-off-by: Rob Clark <robdclark at gmail.com>
>
> So I have no idea, but I thought DT would be standardized enough (register
> ranges seem to be) that we could write a DT helper for this. Not possible?

no, see below

>> ---
>>  drivers/gpu/drm/msm/msm_drv.c   | 20 ++++++++++++++++++++
>>  drivers/gpu/drm/msm/msm_drv.h   |  1 +
>>  drivers/gpu/drm/msm/msm_fbdev.c |  2 +-
>>  3 files changed, 22 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
>> index 9d498eb..0650b2b 100644
>> --- a/drivers/gpu/drm/msm/msm_drv.c
>> +++ b/drivers/gpu/drm/msm/msm_drv.c
>> @@ -372,6 +372,24 @@ static int msm_init_vram(struct drm_device *dev)
>>       return ret;
>>  }
>>
>> +static void msm_kick_out_firmware_fb(void)
>> +{
>> +     struct apertures_struct *ap;
>> +
>> +     ap = alloc_apertures(1);
>> +     if (!ap)
>> +             return;
>> +
>> +     /* Since msm is a UMA device, the simplefb or efifb node may
>> +      * have been located anywhere in memory.
>> +      */
>> +     ap->ranges[0].base = 0;
>> +     ap->ranges[0].size = MAX_RESOURCE;
>> +
>> +     drm_fb_helper_remove_conflicting_framebuffers(ap, FB_NAME, false);
>
> Hm, can we do better? Is there no link in DT between the simplefb and the
> real DT node?

umm, well it could be efifb (ie. not in DT).. although I suppose we
could create a small helper for UMA devices to avoid duplicating 5
lines of code in several drivers.  Not something I'm going to do for a
patch planned for -fixes, but possibly a later patch for 4.14.

BR,
-R

> -Daniel
>
>> +     kfree(ap);
>> +}
>> +
>>  static int msm_drm_init(struct device *dev, struct drm_driver *drv)
>>  {
>>       struct platform_device *pdev = to_platform_device(dev);
>> @@ -424,6 +442,8 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
>>               return ret;
>>       }
>>
>> +     msm_kick_out_firmware_fb();
>> +
>>       ret = msm_init_vram(ddev);
>>       if (ret)
>>               goto fail;
>> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
>> index 1b26ca6..18c5457 100644
>> --- a/drivers/gpu/drm/msm/msm_drv.h
>> +++ b/drivers/gpu/drm/msm/msm_drv.h
>> @@ -56,6 +56,7 @@ struct msm_gem_address_space;
>>  struct msm_gem_vma;
>>
>>  #define NUM_DOMAINS 2    /* one for KMS, then one per gpu core (?) */
>> +#define FB_NAME "msm"
>>
>>  struct msm_file_private {
>>       /* currently we don't do anything useful with this.. but when
>> diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c
>> index 951e40f..b23a191 100644
>> --- a/drivers/gpu/drm/msm/msm_fbdev.c
>> +++ b/drivers/gpu/drm/msm/msm_fbdev.c
>> @@ -146,7 +146,7 @@ static int msm_fbdev_create(struct drm_fb_helper *helper,
>>       fbi->flags = FBINFO_DEFAULT;
>>       fbi->fbops = &msm_fb_ops;
>>
>> -     strcpy(fbi->fix.id, "msm");
>> +     strcpy(fbi->fix.id, FB_NAME);
>>
>>       drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
>>       drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
>> --
>> 2.9.4
>>
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>> dri-devel at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch