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

Maarten Lankhorst maarten.lankhorst at linux.intel.com
Mon Nov 20 11:27:04 UTC 2017


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



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