On Tue, Mar 03, 2026 at 03:38:35PM -0800, Rob Clark wrote: > On Tue, Mar 3, 2026 at 2:32 PM Dmitry Baryshkov > <[email protected]> wrote: > > > > On Tue, Mar 03, 2026 at 10:35:46AM -0800, Rob Clark wrote: > > > 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. > > > > I'd rather break things and hear about them being broken. > > You are assuming you'd hear about the non-obvious breakages > immediately.. I don't think that is a good assumption. > > To be clear, I'll NAK any change to the default for "normal" hw > configurations. If you want to change the modparam to tri-state so > that "weird" hw configurations get split devices, I guess I'd be ok > with that. At least it limits the potential fallout.
Ack :-) > > BR, > -R > > > > > > > BR, > > > -R > > > > > > > BTW: have you tested it with X11? Are you still getting accelerated GPU? > > > > > > > > -- > > > > With best wishes > > > > Dmitry > > > > -- > > With best wishes > > Dmitry -- With best wishes Dmitry
