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

Greg KH gregkh at linuxfoundation.org
Tue Nov 28 09:17:53 UTC 2017


On Fri, Nov 24, 2017 at 07:48:22AM +0100, Greg KH wrote:
> 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...

Now reverted.

thanks,

greg k-h


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