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

Rainer Fiebig jrf at mailbox.org
Thu Nov 23 21:09:25 UTC 2017


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.



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