[Intel-gfx] 4.9.62: intermittent flicker after upgrade from 4.9.61

Greg KH gregkh at linuxfoundation.org
Fri Nov 24 06:48:22 UTC 2017


On Thu, Nov 23, 2017 at 10:09:25PM +0100, Rainer Fiebig wrote:
> Rainer Fiebig wrote:
> > Maarten Lankhorst wrote:
> >> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
> >>> Jani Nikula wrote:
> >>>> On Sun, 19 Nov 2017, Greg KH <gregkh at linuxfoundation.org> wrote:
> >>>>> 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 at vger.kernel.org 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 at 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.
> >>>> Well, this one we wanted to be backported, and so indicated with cc:
> >>>> stable, but apparently it went south anyway. :(
> >>>>
> >>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
> >>>> the backport?
> >>>>
> >>>> Maarten?
> >>>>
> >>>> BR,
> >>>> Jani.
> >>>>
> >>>>
> >>> 4.14 is OK, no problems.
> >>>
> >>> So long!
> >>> Rainer Fiebig
> >>
> >> What happens when you apply both other backported patches on top?
> >>
> >> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
> >>
> > 
> > So I applied the 2 new patches on top of the orig. 4.9.62.
> > 
> > Better now but not yet completely OK:
> > 
> > ...
> > [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> > [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> > ...
> > 
> > No random flicker so far but flicker when I enter a character in an
> > x-terminal.
> > 
> > Seems your patches fixed only half of the pipes. ;)
> > 
> > So long!
> > Rainer Fiebig
> > 
> 
> There's also random flicker after a while.

Ok, I'm just going to revert this patch for the next release unless one
of the i915 developers has a better idea...

thanks,

greg k-h


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