4.9.62: intermittent flicker after upgrade from 4.9.61
Greg KH
gregkh at linuxfoundation.org
Sun Nov 19 12:08:13 UTC 2017
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
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