On Sun, Feb 22, 2026 at 12:32 PM Dmitry Baryshkov
<[email protected]> wrote:
>
> On Mon, Feb 23, 2026 at 12:40:10AM +0530, Mahadevan P wrote:
> > On targets with multiple display subsystems, such as SA8775P, the GPU
> > binds to the first display subsystem that probes. This implicit binding
> > prevents subsequent display subsystems from probing successfully,
> > breaking multi-display support.
> >
> > Enable separate_gpu_kms by default to decouple GPU and display subsystem
> > probing. This allows each display subsystem to initialize independently,
> > ensuring that all display subsystems are probed.
> >
> > Signed-off-by: Mahadevan P <[email protected]>
> > ---
> > Depends on:
> >
> > https://lore.kernel.org/lkml/[email protected]/
> >
> > https://lore.kernel.org/all/[email protected]/
>
> What exactly depends on this patchset?
>
> > ---
> > drivers/gpu/drm/msm/msm_drv.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> > index ed2a61c66ac9..65119fb3dfa2 100644
> > --- a/drivers/gpu/drm/msm/msm_drv.c
> > +++ b/drivers/gpu/drm/msm/msm_drv.c
> > @@ -54,7 +54,7 @@ static bool modeset = true;
> > MODULE_PARM_DESC(modeset, "Use kernel modesetting [KMS] (1=on (default),
> > 0=disable)");
> > module_param(modeset, bool, 0600);
> >
> > -static bool separate_gpu_kms;
> > +static bool separate_gpu_kms = true;
> > MODULE_PARM_DESC(separate_gpu_drm, "Use separate DRM device for the GPU
> > (0=single DRM device for both GPU and display (default), 1=two DRM
> > devices)");
> > module_param(separate_gpu_kms, bool, 0400);
>
> The patch LGTM, but I'd prefer to get confirmation from Rob.
I prefer to be a bit more paranoid.. perhaps switch this to a tri-state:
-1: separate drm devices if there is more than one dpu or gpu,
otherwise, single combined drm device [default]
0: single drm device (matching up pairs of dpu and gpu if needed)
1: separate drm devices
This way we aren't changing (or breaking) things for existing users.
BR,
-R
> BTW: have you tested it with X11? Are you still getting accelerated GPU?
>
> --
> With best wishes
> Dmitry
