| Message ID | 1412876816-2313-1-git-send-email-przanoni@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 2014-10-09 at 14:46 -0300, Paulo Zanoni wrote: > From: Paulo Zanoni <paulo.r.zanoni@intel.com> > > As far as I understand, intel_uncore_early_sanitize() was supposed to > be ran before any register access, but currently > intel_resume_prepare() is ran earlier, and it does register > access. I don't think it should be safe to be calling > I915_{READ,WRITE} without calling intel_uncore_early_sanitize() first. > > One of the problems we currently have is that when we suspend/resume > BDW, the FPGA_DBG_RM_NOCLAIM bit becomes 1, so we end up printing an > "unclaimed register" message on resume, but this message doesn't > really seem to have been triggered by our driver or user space, since > the bit was not there before suspending, and gets there just after > resuming, before any of our own register accesses. So calling > intel_uncore_early_sanitize() as a first thing will allow us to stop > printing the error message, fixing the "bug". One issue is that intel_uncore_early_sanitize() uses forcewake, which is enabled only in prepare resume for VLV (vlv_allow_gt_wake()). Maybe FPGA_DBG could be reset separately before the rest? > > Cc: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Imre Deak <imre.deak@intel.com> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83094 > Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> > --- > drivers/gpu/drm/i915/i915_drv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Maybe we need to move even more code up? > > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c > index a05a1d0..dffb173 100644 > --- a/drivers/gpu/drm/i915/i915_drv.c > +++ b/drivers/gpu/drm/i915/i915_drv.c > @@ -665,11 +665,11 @@ static int i915_drm_thaw_early(struct drm_device *dev) > struct drm_i915_private *dev_priv = dev->dev_private; > int ret; > > + intel_uncore_early_sanitize(dev, true); > ret = intel_resume_prepare(dev_priv, false); > if (ret) > DRM_ERROR("Resume prepare failed: %d,Continuing resume\n", ret); > > - intel_uncore_early_sanitize(dev, true); > intel_uncore_sanitize(dev); > intel_power_domains_init_hw(dev_priv); >
2014-10-10 8:25 GMT-03:00 Imre Deak <imre.deak@intel.com>: > On Thu, 2014-10-09 at 14:46 -0300, Paulo Zanoni wrote: >> From: Paulo Zanoni <paulo.r.zanoni@intel.com> >> >> As far as I understand, intel_uncore_early_sanitize() was supposed to >> be ran before any register access, but currently >> intel_resume_prepare() is ran earlier, and it does register >> access. I don't think it should be safe to be calling >> I915_{READ,WRITE} without calling intel_uncore_early_sanitize() first. >> >> One of the problems we currently have is that when we suspend/resume >> BDW, the FPGA_DBG_RM_NOCLAIM bit becomes 1, so we end up printing an >> "unclaimed register" message on resume, but this message doesn't >> really seem to have been triggered by our driver or user space, since >> the bit was not there before suspending, and gets there just after >> resuming, before any of our own register accesses. So calling >> intel_uncore_early_sanitize() as a first thing will allow us to stop >> printing the error message, fixing the "bug". > > One issue is that intel_uncore_early_sanitize() uses forcewake, which is > enabled only in prepare resume for VLV (vlv_allow_gt_wake()). Maybe > FPGA_DBG could be reset separately before the rest? It doesn't "use" forcewake, it calls intel_uncore_forcewake_reset(). Shouldn't we move the vlv code (e.g., vlv_allow_gt_wake()) to inside intel_uncore_forcewake_reset() instead? To my understanding, it doesn't make sense to call anything at all before intel_uncore_early_sanitize()... > >> >> Cc: Chris Wilson <chris@chris-wilson.co.uk> >> Cc: Imre Deak <imre.deak@intel.com> >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83094 >> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> >> --- >> drivers/gpu/drm/i915/i915_drv.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> Maybe we need to move even more code up? >> >> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c >> index a05a1d0..dffb173 100644 >> --- a/drivers/gpu/drm/i915/i915_drv.c >> +++ b/drivers/gpu/drm/i915/i915_drv.c >> @@ -665,11 +665,11 @@ static int i915_drm_thaw_early(struct drm_device *dev) >> struct drm_i915_private *dev_priv = dev->dev_private; >> int ret; >> >> + intel_uncore_early_sanitize(dev, true); >> ret = intel_resume_prepare(dev_priv, false); >> if (ret) >> DRM_ERROR("Resume prepare failed: %d,Continuing resume\n", ret); >> >> - intel_uncore_early_sanitize(dev, true); >> intel_uncore_sanitize(dev); >> intel_power_domains_init_hw(dev_priv); >> > >
On Wed, 2014-10-15 at 16:07 -0300, Paulo Zanoni wrote: > 2014-10-10 8:25 GMT-03:00 Imre Deak <imre.deak@intel.com>: > > On Thu, 2014-10-09 at 14:46 -0300, Paulo Zanoni wrote: > >> From: Paulo Zanoni <paulo.r.zanoni@intel.com> > >> > >> As far as I understand, intel_uncore_early_sanitize() was supposed to > >> be ran before any register access, but currently > >> intel_resume_prepare() is ran earlier, and it does register > >> access. I don't think it should be safe to be calling > >> I915_{READ,WRITE} without calling intel_uncore_early_sanitize() first. > >> > >> One of the problems we currently have is that when we suspend/resume > >> BDW, the FPGA_DBG_RM_NOCLAIM bit becomes 1, so we end up printing an > >> "unclaimed register" message on resume, but this message doesn't > >> really seem to have been triggered by our driver or user space, since > >> the bit was not there before suspending, and gets there just after > >> resuming, before any of our own register accesses. So calling > >> intel_uncore_early_sanitize() as a first thing will allow us to stop > >> printing the error message, fixing the "bug". > > > > One issue is that intel_uncore_early_sanitize() uses forcewake, which is > > enabled only in prepare resume for VLV (vlv_allow_gt_wake()). Maybe > > FPGA_DBG could be reset separately before the rest? > > It doesn't "use" forcewake, it calls intel_uncore_forcewake_reset(). Hm, right I only remembered that because of "drm/i915: check for GT faults during S3 resume and S4 restore too" on the mailing list, but it's not yet merged. > Shouldn't we move the vlv code (e.g., vlv_allow_gt_wake()) to inside > intel_uncore_forcewake_reset() instead? > > To my understanding, it doesn't make sense to call anything at all > before intel_uncore_early_sanitize()... On VLV we need to do the steps in the resume_prepare handler first. Also we don't want to call vlv_allow_gt_wake() during driver init. But yes, I see that for other platforms it makes sense to move intel_uncore_early_sanitize() earlier. One way would be to call it from resume_prepare for each platform at the proper place in case of system resume. > > > >> > >> Cc: Chris Wilson <chris@chris-wilson.co.uk> > >> Cc: Imre Deak <imre.deak@intel.com> > >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83094 > >> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> > >> --- > >> drivers/gpu/drm/i915/i915_drv.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> Maybe we need to move even more code up? > >> > >> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c > >> index a05a1d0..dffb173 100644 > >> --- a/drivers/gpu/drm/i915/i915_drv.c > >> +++ b/drivers/gpu/drm/i915/i915_drv.c > >> @@ -665,11 +665,11 @@ static int i915_drm_thaw_early(struct drm_device *dev) > >> struct drm_i915_private *dev_priv = dev->dev_private; > >> int ret; > >> > >> + intel_uncore_early_sanitize(dev, true); > >> ret = intel_resume_prepare(dev_priv, false); > >> if (ret) > >> DRM_ERROR("Resume prepare failed: %d,Continuing resume\n", ret); > >> > >> - intel_uncore_early_sanitize(dev, true); > >> intel_uncore_sanitize(dev); > >> intel_power_domains_init_hw(dev_priv); > >> > > > > > > >
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index a05a1d0..dffb173 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -665,11 +665,11 @@ static int i915_drm_thaw_early(struct drm_device *dev) struct drm_i915_private *dev_priv = dev->dev_private; int ret; + intel_uncore_early_sanitize(dev, true); ret = intel_resume_prepare(dev_priv, false); if (ret) DRM_ERROR("Resume prepare failed: %d,Continuing resume\n", ret); - intel_uncore_early_sanitize(dev, true); intel_uncore_sanitize(dev); intel_power_domains_init_hw(dev_priv);