Re: [PATCH] drm/msm: enable separate_gpu_kms by default

[Dmitry Baryshkov]

On Wed, Feb 25, 2026 at 02:58:49PM +0530, Mahadevan P wrote:
> 
> 
> On 2/23/2026 2:02 AM, Dmitry Baryshkov 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 <mahadevan.p@xxxxxxxxxxxxxxxx>
> > > ---
> > > Depends on:
> 	[1]
> > > 	https://lore.kernel.org/lkml/20260124-adreno-module-table-v1-1-9c2dbb2638b4@xxxxxxxxxxxxxxxx/
> 	[2]
> > > 	https://lore.kernel.org/all/20260217071420.2240380-1-mkuntuma@xxxxxxxxxxxxxxxx/
> > 
> > What exactly depends on this patchset?
> The dependency is as follows:
> As we separate out module loading of adreno and mdss with separate_gpu_kms=1
> autoloading of msm.ko fails. With change [1] on bootup, msm.ko is loaded and
> gpu card is created.
> 
> The main reason to bring this patch here in upstream is for enabling of dual
> dpu configuration in Lemans hence added [2] as dependency.

None of that describes why they are dependencies (i.e. must be applied
_before_ this patch, which otherwise will be broken).

> 
> > 
> > > ---
> > >   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.
> > 
> > BTW: have you tested it with X11? Are you still getting accelerated GPU?
> 
> Yes, tested today with X11 app(xterm), GPU rendering is used.
> > 
> 
> Thanks,
> Mahadevan

-- 
With best wishes
Dmitry