On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
> Greg KH wrote:
> > On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
> >> Greg KH wrote:
> >>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
> >>>> Greg KH wrote:
> >>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
> >>>>>> Hi!
> >>>>>>
> >>>>>> Hopefully the right addressee.
> >>>>>>
> >>>>>> Encountered two bad backports which cause screen-flicker.
> >>>>>> dmesg shows:
> >>>>>>
> >>>>>> ...
> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
> >>>>>> ...
> >>>>>>
> >>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
> >>>>>>
> >>>>>> The backports are:
> >>>>>>
> >>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
> >>>>>> b/drivers/gpu/drm/i915/intel_pm.c
> >>>>>> index 49de476..277a802 100644
> >>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
> >>>>>> b/drivers/gpu/drm/i915/intel_drv.h
> >>>>>> index a19ec06..3ce9ba3 100644
> >>>>>>
> >>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
> >>>>>> else OK so far.
> >>>>>
> >>>>> So which commit was the one that caused the problem? I will be glad to
> >>>>> revert it.
> >>>>>
> >>>>> thanks,
> >>>>>
> >>>>> greg k-h
> >>>>>
> >>>>>
> >>>>
> >>>> I started by reverting the more complex one first ("index
> >>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
> >>>
> >>> What git commit id is that? I don't see those ids in the 4.9-stable
> >>> tree.
> >>>
> >>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
> >>>> kernel compiled just fine and the problems were gone (still are).
> >>>
> >>> Same here, what git commit id was this?
> >>>
> >>> thanks,
> >>>
> >>> greg k-h
> >>>
> >>
> >> OK, no mistake. IIRC, I took the patches (and the IDs) from the
> >> changelog for patch-4.9.62. I've attached both, so you can check yourself.
> >>
> >> I've also applied a freshly downloaded patch-4.9.62 to a freshly
> >> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
> >> reverted the two patches but I'm confident that after having done so the
> >> flicker will be gone. If not I'll let you know.
> >>
> >> As a good news: 4.14 is *not* affected. So to me it seems those two
> >> patches are part of sort of a package and can not be backported alone.
> >>
> >> So long!
> >> Rainer Fiebig
> >
> >> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> >> index 49de476..277a802 100644
> >> --- a/drivers/gpu/drm/i915/intel_pm.c
> >> +++ b/drivers/gpu/drm/i915/intel_pm.c
> >> @@ -27,6 +27,7 @@
> >>
> >> #include <linux/cpufreq.h>
> >> #include <drm/drm_plane_helper.h>
> >> +#include <drm/drm_atomic_helper.h>
> >> #include "i915_drv.h"
> >> #include "intel_drv.h"
> >> #include "../../../platform/x86/intel_ips.h"
> >> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
> >> const struct intel_crtc *intel_crtc,
> >> int level,
> >> struct intel_crtc_state *cstate,
> >> - struct intel_plane_state *pristate,
> >> - struct intel_plane_state *sprstate,
> >> - struct intel_plane_state *curstate,
> >> + const struct intel_plane_state *pristate,
> >> + const struct intel_plane_state *sprstate,
> >> + const struct intel_plane_state *curstate,
> >> struct intel_wm_level *result)
> >> {
> >> uint16_t pri_latency = dev_priv->wm.pri_latency[level];
> >> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >> struct intel_pipe_wm *pipe_wm;
> >> struct drm_device *dev = state->dev;
> >> const struct drm_i915_private *dev_priv = to_i915(dev);
> >> - struct intel_plane *intel_plane;
> >> - struct intel_plane_state *pristate = NULL;
> >> - struct intel_plane_state *sprstate = NULL;
> >> - struct intel_plane_state *curstate = NULL;
> >> + struct drm_plane *plane;
> >> + const struct drm_plane_state *plane_state;
> >> + const struct intel_plane_state *pristate = NULL;
> >> + const struct intel_plane_state *sprstate = NULL;
> >> + const struct intel_plane_state *curstate = NULL;
> >> int level, max_level = ilk_wm_max_level(dev), usable_level;
> >> struct ilk_wm_maximums max;
> >>
> >> pipe_wm = &cstate->wm.ilk.optimal;
> >>
> >> - for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> >> - struct intel_plane_state *ps;
> >> + drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
> >> + const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
> >>
> >> - ps = intel_atomic_get_existing_plane_state(state,
> >> - intel_plane);
> >> - if (!ps)
> >> - continue;
> >> -
> >> - if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
> >> + if (plane->type == DRM_PLANE_TYPE_PRIMARY)
> >> pristate = ps;
> >> - else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
> >> + else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
> >> sprstate = ps;
> >> - else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
> >> + else if (plane->type == DRM_PLANE_TYPE_CURSOR)
> >> curstate = ps;
> >> }
> >>
> >> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >> if (pipe_wm->sprites_scaled)
> >> usable_level = 0;
> >>
> >> - ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> >> - pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
> >> -
> >> memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
> >> - pipe_wm->wm[0] = pipe_wm->raw_wm[0];
> >> + ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> >> + pristate, sprstate, curstate, &pipe_wm->wm[0]);
> >>
> >> if (IS_HASWELL(dev) || IS_BROADWELL(dev))
> >> pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
> >> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >>
> >> ilk_compute_wm_reg_maximums(dev, 1, &max);
> >>
> >> - for (level = 1; level <= max_level; level++) {
> >> - struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
> >> + for (level = 1; level <= usable_level; level++) {
> >> + struct intel_wm_level *wm = &pipe_wm->wm[level];
> >>
> >> ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
> >> pristate, sprstate, curstate, wm);
> >> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >> * register maximums since such watermarks are
> >> * always invalid.
> >> */
> >> - if (level > usable_level)
> >> - continue;
> >> -
> >> - if (ilk_validate_wm_level(level, &max, wm))
> >> - pipe_wm->wm[level] = *wm;
> >> - else
> >> - usable_level = level;
> >> + if (!ilk_validate_wm_level(level, &max, wm)) {
> >> + memset(wm, 0, sizeof(*wm));
> >> + break;
> >> + }
> >> }
> >>
> >> return 0;
> >
> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >> index a19ec06..3ce9ba3 100644
> >> --- a/drivers/gpu/drm/i915/intel_drv.h
> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
> >>
> >> struct intel_pipe_wm {
> >> struct intel_wm_level wm[5];
> >> - struct intel_wm_level raw_wm[5];
> >> uint32_t linetime;
> >> bool fbc_wm_enabled;
> >> bool pipe_enabled;
> >
> > Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
> > upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
> > 4.9.62.
> >
> > I've cc:ed the authors of that patch now.
> >
> > Maarten, any hints? Should I revert this from 4.9-stable, or was there
> > a follow-on patch that resolved this issue in mainline?
> >
> > thanks,
> >
> > greg k-h
> >
>
> OK, after reverting the patches, the flicker *is* gone.
Thanks for confirming this.
> BTW (for the future): Was it the right way to address
> stable@xxxxxxxxxxxxxxx in this matter or would the bugreport at
> freedesktop.org have been enough? I'm a bit unsure about that.
I have no idea what the i915 developers want, but as far as I'm
concerned, sending this to stable@vger was fine with me, I have no
problem doing a bit of work in tracking down the specific patch before
bugging the developers involved.
thanks,
greg k-h