[PATCH 3/5] drm/i915/gvt: Fix virtual display setup for BXT/APL

[Greg KH]

On Fri, Mar 19, 2021 at 10:39:30AM +0100, Greg KH wrote:
> On Wed, Mar 17, 2021 at 10:55:02AM +0800, Colin Xu wrote:
> > commit a5a8ef937cfa79167f4b2a5602092b8d14fd6b9a upstream
> > 
> > Program display related vregs to proper value at initialization, setup
> > virtual monitor and hotplug.
> > 
> > vGPU virtual display vregs inherit the value from pregs. The virtual DP
> > monitor is always setup on PORT_B for BXT/APL. However the host may
> > connect monitor on other PORT or without any monitor connected. Without
> > properly setup PIPE/DDI/PLL related vregs, guest driver may not setup
> > the virutal display as expected, and the guest desktop may not be
> > created.
> > Since only one virtual display is supported, enable PIPE_A only. And
> > enable transcoder/DDI/PLL based on which port is setup for BXT/APL.
> > 
> > V2:
> > Revise commit message.
> > 
> > V3:
> > set_edid should on PORT_B for BXT.
> > Inject hpd event for BXT.
> > 
> > V4:
> > Temporarily disable vfio edid on BXT/APL until issue fixed.
> > 
> > V5:
> > Rebase to use new HPD define GEN8_DE_PORT_HOTPLUG for BXT.
> > Put vfio edid disabling on BXT/APL to a separate patch.
> > 
> > Acked-by: Zhenyu Wang <zhenyuw at linux.intel.com>
> > Signed-off-by: Colin Xu <colin.xu at intel.com>
> > Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
> > Link: http://patchwork.freedesktop.org/patch/msgid/20201109073922.757759-1-colin.xu@intel.com
> > (cherry picked from commit a5a8ef937cfa79167f4b2a5602092b8d14fd6b9a)
> > Signed-off-by: Colin Xu <colin.xu at intel.com>
> > Cc: <stable at vger.kernel.org> # 5.4.y
> > ---
> >  drivers/gpu/drm/i915/gvt/display.c | 173 +++++++++++++++++++++++++++++
> >  drivers/gpu/drm/i915/gvt/mmio.c    |   5 +
> >  2 files changed, 178 insertions(+)
> 
> I've taken this backport for 5.10.y as well, because it is missing
> there.

Oops, nope, it breaks the build.

Please also provide a working backport for this as well, we can not have
users moving to a newer kernel version and have a regression for a known
issue.

thanks,

greg k-h