| Message ID | 1444242857-10349-1-git-send-email-wayne.boyer@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Oct 07, 2015 at 11:34:17AM -0700, Wayne Boyer wrote: > From: Chris Wilson <chris@chris-wilson.co.uk> > > A long time ago (before 3.14) we relied on a permanent pinning of the > ifbdev to lock the fb in place inside the GGTT. However, the > introduction of stealing the BIOS framebuffer and reusing its address in > the GGTT for the fbdev has muddied waters and we use an inherited fb. > However, the inherited fb is only pinned whilst it is active and we no > longer have an explicit pin for the info->system_base mmapping used by > the fbdev. The result is that after some aperture pressure the fbdev may > be evicted, but we continue to write the fbcon into the same GGTT > address - overwriting anything else that may be put into that offset. > The effect is most pronounced across suspend/resume as > intel_fbdev_set_suspend() does a full clear over the whole scanout. > > v2: rebased on latest nightly (Wayne) > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: "Goel, Akash" <akash.goel@intel.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Jesse Barnes <jbarnes@virtuousgeek.org> > Cc: stable@vger.kernel.org > Reviewed-by: Deepak S <deepak.s@linux.intel.com> > Signed-off-by: Wayne Boyer <wayne.boyer@intel.com> > --- > drivers/gpu/drm/i915/intel_fbdev.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c > index 6532912..c6aa4f9 100644 > --- a/drivers/gpu/drm/i915/intel_fbdev.c > +++ b/drivers/gpu/drm/i915/intel_fbdev.c > @@ -215,6 +215,16 @@ static int intelfb_create(struct drm_fb_helper *helper, > obj = intel_fb->obj; > size = obj->base.size; > > + /* The fb constructor will have already pinned us (or inherited a > + * GGTT region from the BIOS) suitable for a scanout, so > + * this should just be a no-op and increment the pin count for the > + * fbdev mmapping. It does have a useful side-effect of validating > + * the pin for fbdev's use via a GGTT mmapping. > + */ > + ret = i915_gem_object_ggtt_pin(obj, NULL, 0, PIN_MAPPABLE); This should be i915_gem_obj_ggtt_pin(obj, 0, PIN_MAPPABLE); At which point I just rage quit. -Chris
On 10/08/2015 02:07 AM, Chris Wilson wrote: > On Wed, Oct 07, 2015 at 11:34:17AM -0700, Wayne Boyer wrote: >> From: Chris Wilson <chris@chris-wilson.co.uk> >> >> A long time ago (before 3.14) we relied on a permanent pinning of the >> ifbdev to lock the fb in place inside the GGTT. However, the >> introduction of stealing the BIOS framebuffer and reusing its address in >> the GGTT for the fbdev has muddied waters and we use an inherited fb. >> However, the inherited fb is only pinned whilst it is active and we no >> longer have an explicit pin for the info->system_base mmapping used by >> the fbdev. The result is that after some aperture pressure the fbdev may >> be evicted, but we continue to write the fbcon into the same GGTT >> address - overwriting anything else that may be put into that offset. >> The effect is most pronounced across suspend/resume as >> intel_fbdev_set_suspend() does a full clear over the whole scanout. >> >> v2: rebased on latest nightly (Wayne) >> >> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> >> Cc: "Goel, Akash" <akash.goel@intel.com> >> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> >> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> >> Cc: stable@vger.kernel.org >> Reviewed-by: Deepak S <deepak.s@linux.intel.com> >> Signed-off-by: Wayne Boyer <wayne.boyer@intel.com> >> --- >> drivers/gpu/drm/i915/intel_fbdev.c | 15 +++++++++++++++ >> 1 file changed, 15 insertions(+) >> >> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c >> index 6532912..c6aa4f9 100644 >> --- a/drivers/gpu/drm/i915/intel_fbdev.c >> +++ b/drivers/gpu/drm/i915/intel_fbdev.c >> @@ -215,6 +215,16 @@ static int intelfb_create(struct drm_fb_helper *helper, >> obj = intel_fb->obj; >> size = obj->base.size; >> >> + /* The fb constructor will have already pinned us (or inherited a >> + * GGTT region from the BIOS) suitable for a scanout, so >> + * this should just be a no-op and increment the pin count for the >> + * fbdev mmapping. It does have a useful side-effect of validating >> + * the pin for fbdev's use via a GGTT mmapping. >> + */ >> + ret = i915_gem_object_ggtt_pin(obj, NULL, 0, PIN_MAPPABLE); > > This should be i915_gem_obj_ggtt_pin(obj, 0, PIN_MAPPABLE); > At which point I just rage quit. LOL GEM naming strikes again! Jesse
diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c index 6532912..c6aa4f9 100644 --- a/drivers/gpu/drm/i915/intel_fbdev.c +++ b/drivers/gpu/drm/i915/intel_fbdev.c @@ -215,6 +215,16 @@ static int intelfb_create(struct drm_fb_helper *helper, obj = intel_fb->obj; size = obj->base.size; + /* The fb constructor will have already pinned us (or inherited a + * GGTT region from the BIOS) suitable for a scanout, so + * this should just be a no-op and increment the pin count for the + * fbdev mmapping. It does have a useful side-effect of validating + * the pin for fbdev's use via a GGTT mmapping. + */ + ret = i915_gem_object_ggtt_pin(obj, NULL, 0, PIN_MAPPABLE); + if (ret) + goto out_unlock; + info = drm_fb_helper_alloc_fbi(helper); if (IS_ERR(info)) { ret = PTR_ERR(info); @@ -274,6 +284,9 @@ static int intelfb_create(struct drm_fb_helper *helper, out_destroy_fbi: drm_fb_helper_release_fbi(helper); out_unpin: + /* Once for info->screen_base mmaping... */ + i915_gem_object_ggtt_unpin(obj); + /* ...and once for the intel_fb */ i915_gem_object_ggtt_unpin(obj); drm_gem_object_unreference(&obj->base); out_unlock: @@ -514,6 +527,8 @@ static const struct drm_fb_helper_funcs intel_fb_helper_funcs = { static void intel_fbdev_destroy(struct drm_device *dev, struct intel_fbdev *ifbdev) { + /* Release the pinning for the info->screen_base mmaping. */ + i915_gem_object_ggtt_unpin(ifbdev->fb->obj); drm_fb_helper_unregister_fbi(&ifbdev->helper); drm_fb_helper_release_fbi(&ifbdev->helper);