Jani Nikula wrote:
> On Sun, 19 Nov 2017, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx 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@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