* [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
@ 2017-05-26 6:07 Quanxian Wang
2017-05-26 6:27 ` ✓ Fi.CI.BAT: success for " Patchwork
2017-05-26 8:31 ` [PATCH] " Jani Nikula
0 siblings, 2 replies; 9+ messages in thread
From: Quanxian Wang @ 2017-05-26 6:07 UTC (permalink / raw)
To: intel-gfx
According to the bspec, when set N/M, should disable
and enable transcoder which attaching DP audio. However
with that implementation will affect performance more.
But with current implementation, KBL could not work with defined N/M.
By default, KBL will use automatic N/M.
Signed-off-by: Quanxian Wang <quanxian.wang@intel.com>
Reviewed-by: Libin Yang <libin.yang@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
---
drivers/gpu/drm/i915/intel_audio.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index d805b6e..ba4994e 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -289,6 +289,10 @@ hsw_dp_audio_config_update(struct intel_crtc *intel_crtc, enum port port,
enum pipe pipe = intel_crtc->pipe;
u32 tmp;
+ /* It doesn't work on KBL and uses automatic N/M. */
+ if (IS_KABYLAKE(dev_priv))
+ nm = NULL;
+
if (nm)
DRM_DEBUG_KMS("using Maud %u, Naud %u\n", nm->m, nm->n);
else
--
2.5.0
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply related [flat|nested] 9+ messages in thread
* ✓ Fi.CI.BAT: success for Defined NM doesn't work on KBL and uses automatic N/M.
2017-05-26 6:07 [PATCH] Defined NM doesn't work on KBL and uses automatic N/M Quanxian Wang
@ 2017-05-26 6:27 ` Patchwork
2017-05-26 8:31 ` [PATCH] " Jani Nikula
1 sibling, 0 replies; 9+ messages in thread
From: Patchwork @ 2017-05-26 6:27 UTC (permalink / raw)
To: Quanxian Wang; +Cc: intel-gfx
== Series Details ==
Series: Defined NM doesn't work on KBL and uses automatic N/M.
URL : https://patchwork.freedesktop.org/series/24938/
State : success
== Summary ==
Series 24938v1 Defined NM doesn't work on KBL and uses automatic N/M.
https://patchwork.freedesktop.org/api/1.0/series/24938/revisions/1/mbox/
fi-bdw-5557u total:278 pass:267 dwarn:0 dfail:0 fail:0 skip:11 time:446s
fi-bdw-gvtdvm total:278 pass:256 dwarn:8 dfail:0 fail:0 skip:14 time:428s
fi-bsw-n3050 total:278 pass:242 dwarn:0 dfail:0 fail:0 skip:36 time:579s
fi-bxt-j4205 total:278 pass:259 dwarn:0 dfail:0 fail:0 skip:19 time:513s
fi-byt-j1900 total:278 pass:254 dwarn:0 dfail:0 fail:0 skip:24 time:485s
fi-byt-n2820 total:278 pass:250 dwarn:0 dfail:0 fail:0 skip:28 time:484s
fi-hsw-4770 total:278 pass:262 dwarn:0 dfail:0 fail:0 skip:16 time:421s
fi-hsw-4770r total:278 pass:262 dwarn:0 dfail:0 fail:0 skip:16 time:410s
fi-ilk-650 total:278 pass:228 dwarn:0 dfail:0 fail:0 skip:50 time:418s
fi-ivb-3520m total:278 pass:260 dwarn:0 dfail:0 fail:0 skip:18 time:484s
fi-ivb-3770 total:278 pass:260 dwarn:0 dfail:0 fail:0 skip:18 time:468s
fi-kbl-7500u total:278 pass:255 dwarn:5 dfail:0 fail:0 skip:18 time:462s
fi-kbl-7560u total:278 pass:263 dwarn:5 dfail:0 fail:0 skip:10 time:570s
fi-skl-6260u total:278 pass:268 dwarn:0 dfail:0 fail:0 skip:10 time:462s
fi-skl-6700hq total:278 pass:239 dwarn:0 dfail:1 fail:17 skip:21 time:438s
fi-skl-6700k total:278 pass:256 dwarn:4 dfail:0 fail:0 skip:18 time:464s
fi-skl-6770hq total:278 pass:268 dwarn:0 dfail:0 fail:0 skip:10 time:499s
fi-skl-gvtdvm total:278 pass:265 dwarn:0 dfail:0 fail:0 skip:13 time:440s
fi-snb-2520m total:278 pass:250 dwarn:0 dfail:0 fail:0 skip:28 time:541s
fi-snb-2600 total:278 pass:249 dwarn:0 dfail:0 fail:0 skip:29 time:398s
d47b71fd942d8a88da311863a6cfc2fd73ba1234 drm-tip: 2017y-05m-25d-20h-54m-23s UTC integration manifest
3784560 Defined NM doesn't work on KBL and uses automatic N/M.
== Logs ==
For more details see: https://intel-gfx-ci.01.org/CI/Patchwork_4815/
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
2017-05-26 6:07 [PATCH] Defined NM doesn't work on KBL and uses automatic N/M Quanxian Wang
2017-05-26 6:27 ` ✓ Fi.CI.BAT: success for " Patchwork
@ 2017-05-26 8:31 ` Jani Nikula
2017-05-26 9:52 ` Wang, Quanxian
1 sibling, 1 reply; 9+ messages in thread
From: Jani Nikula @ 2017-05-26 8:31 UTC (permalink / raw)
To: Quanxian Wang, intel-gfx
On Fri, 26 May 2017, Quanxian Wang <quanxian.wang@intel.com> wrote:
> According to the bspec, when set N/M, should disable
> and enable transcoder which attaching DP audio. However
> with that implementation will affect performance more.
>
> But with current implementation, KBL could not work with defined N/M.
> By default, KBL will use automatic N/M.
>
> Signed-off-by: Quanxian Wang <quanxian.wang@intel.com>
> Reviewed-by: Libin Yang <libin.yang@intel.com>
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
I have *NOT* reviewed this patch. Even if it's based on my suggestion in
[1], it does not automatically signify review.
The patch subject should start with "drm/i915/audio:".
The DP spec always expresses the values as M/N, more specifically
Maud/Naud, so it's confusing to see them expressed as N/M.
I still have trouble understanding the commit message. I am wondering if
something was fixed in Kabylake and beyond, since according to
6014ac122ed0 ("drm/i915/audio: set proper N/M in modeset") we need this
for certain modes. In particular, should the condition check for KBL ||
gen >= 10?
BR,
Jani.
[1] http://mid.mail-archive.com/87pogs1lz7.fsf@intel.com
> ---
> drivers/gpu/drm/i915/intel_audio.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
> index d805b6e..ba4994e 100644
> --- a/drivers/gpu/drm/i915/intel_audio.c
> +++ b/drivers/gpu/drm/i915/intel_audio.c
> @@ -289,6 +289,10 @@ hsw_dp_audio_config_update(struct intel_crtc *intel_crtc, enum port port,
> enum pipe pipe = intel_crtc->pipe;
> u32 tmp;
>
> + /* It doesn't work on KBL and uses automatic N/M. */
> + if (IS_KABYLAKE(dev_priv))
> + nm = NULL;
> +
> if (nm)
> DRM_DEBUG_KMS("using Maud %u, Naud %u\n", nm->m, nm->n);
> else
--
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
2017-05-26 8:31 ` [PATCH] " Jani Nikula
@ 2017-05-26 9:52 ` Wang, Quanxian
2017-05-26 11:00 ` Jani Nikula
0 siblings, 1 reply; 9+ messages in thread
From: Wang, Quanxian @ 2017-05-26 9:52 UTC (permalink / raw)
To: Jani Nikula, intel-gfx
Hi, Jani
Thanks for your comment. My comment below.
-----Original Message-----
From: Jani Nikula [mailto:jani.nikula@linux.intel.com]
Sent: Friday, May 26, 2017 4:31 PM
To: Wang, Quanxian <quanxian.wang@intel.com>; intel-gfx@lists.freedesktop.org
Cc: Yang, Libin <libin.yang@intel.com>; Wang, Quanxian <quanxian.wang@intel.com>
Subject: Re: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
On Fri, 26 May 2017, Quanxian Wang <quanxian.wang@intel.com> wrote:
> According to the bspec, when set N/M, should disable and enable
> transcoder which attaching DP audio. However with that implementation
> will affect performance more.
>
> But with current implementation, KBL could not work with defined N/M.
> By default, KBL will use automatic N/M.
>
> Signed-off-by: Quanxian Wang <quanxian.wang@intel.com>
> Reviewed-by: Libin Yang <libin.yang@intel.com>
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
I have *NOT* reviewed this patch. Even if it's based on my suggestion in [1], it does not automatically signify review.
[Wang, Quanxian] Sorry, I accept your suggestion. So in order to respect what you said, I input your name here.
The patch subject should start with "drm/i915/audio:".
[Wang, Quanxian] Ok.
The DP spec always expresses the values as M/N, more specifically Maud/Naud, so it's confusing to see them expressed as N/M.
[Wang, Quanxian] accept it.
I still have trouble understanding the commit message. I am wondering if something was fixed in Kabylake and beyond, since according to
[Wang, Quanxian] in Ubuntu 17.04, we do audio testing on KBL/SKL/APL and more, the audio doesn't work on KBL specially, and other platform works fine. Even if with latest upstream kernel, but it works on 4.8 kernel. Therefore It is a regression issue. After investigation, we found it is caused by commit "6014ac122ed081feca99217bc57b2e15c7fc1a51] drm/i915/audio: set proper N/M in modeset". Therefore I provided this patch.
After getting suggestion from you and Libin, we do more testing on 4K monitor for audio delay issue. Also talked with Libin why not use transcoder disable/enable process described in bspec, it will affect performance.
This is the whole story. You can check LCK number 3791 in Intel JIRA about that.
6014ac122ed0 ("drm/i915/audio: set proper N/M in modeset") we need this for certain modes. In particular, should the condition check for KBL || gen >= 10?
[Wang, Quanxian] Basically if upstream could provide a reasonable patch, it will appreciate since you are expert in this area.
Thanks for your understanding.
BR,
Jani.
[1] http://mid.mail-archive.com/87pogs1lz7.fsf@intel.com
> ---
> drivers/gpu/drm/i915/intel_audio.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_audio.c
> b/drivers/gpu/drm/i915/intel_audio.c
> index d805b6e..ba4994e 100644
> --- a/drivers/gpu/drm/i915/intel_audio.c
> +++ b/drivers/gpu/drm/i915/intel_audio.c
> @@ -289,6 +289,10 @@ hsw_dp_audio_config_update(struct intel_crtc *intel_crtc, enum port port,
> enum pipe pipe = intel_crtc->pipe;
> u32 tmp;
>
> + /* It doesn't work on KBL and uses automatic N/M. */
> + if (IS_KABYLAKE(dev_priv))
> + nm = NULL;
> +
> if (nm)
> DRM_DEBUG_KMS("using Maud %u, Naud %u\n", nm->m, nm->n);
> else
--
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
2017-05-26 9:52 ` Wang, Quanxian
@ 2017-05-26 11:00 ` Jani Nikula
2017-05-26 21:36 ` Wang, Quanxian
0 siblings, 1 reply; 9+ messages in thread
From: Jani Nikula @ 2017-05-26 11:00 UTC (permalink / raw)
To: Wang, Quanxian, intel-gfx
On Fri, 26 May 2017, "Wang, Quanxian" <quanxian.wang@intel.com> wrote:
> [Wang, Quanxian] in Ubuntu 17.04, we do audio testing on KBL/SKL/APL
> and more, the audio doesn't work on KBL specially, and other platform
> works fine. Even if with latest upstream kernel, but it works on 4.8
> kernel. Therefore It is a regression issue. After investigation, we
> found it is caused by commit
> "6014ac122ed081feca99217bc57b2e15c7fc1a51] drm/i915/audio: set proper
> N/M in modeset". Therefore I provided this patch.
If it's a regression, we need to backport the fix to stable kernels, and
the patch needs annotation:
Fixes: 6014ac122ed0 ("drm/i915/audio: set proper N/M in modeset")
Cc: <stable@vger.kernel.org> # v4.10+
> After getting suggestion from you and Libin, we do more testing on 4K
> monitor for audio delay issue. Also talked with Libin why not use
> transcoder disable/enable process described in bspec, it will affect
> performance.
>
> This is the whole story. You can check LCK number 3791 in Intel JIRA
> about that.
Actually, I can't. And the commit message needs to have the
explanation. I still do not know what the bug is specifically, or why
Kabylake, and only Kabylake, needs this.
> [Wang, Quanxian] Basically if upstream could provide a reasonable
> patch, it will appreciate since you are expert in this area.
> Thanks for your understanding.
The patch is probably fine. But I can't invent an explanation if I don't
know what the problem is.
BR,
Jani.
--
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
2017-05-26 11:00 ` Jani Nikula
@ 2017-05-26 21:36 ` Wang, Quanxian
2017-05-29 8:29 ` Jani Nikula
0 siblings, 1 reply; 9+ messages in thread
From: Wang, Quanxian @ 2017-05-26 21:36 UTC (permalink / raw)
To: Jani Nikula, intel-gfx
"The patch is probably fine. But I can't invent an explanation if I don't know what the problem is."
@Jani @libin, is it possible for you to help contact Intel graphics hardware design engineer to get the reason why M/N doesn't work as you implemented in kernel code in Kabylake platform? I don't find good reason in bspec. Thanks.
-----Original Message-----
From: Jani Nikula [mailto:jani.nikula@linux.intel.com]
Sent: Friday, May 26, 2017 7:01 PM
To: Wang, Quanxian <quanxian.wang@intel.com>; intel-gfx@lists.freedesktop.org
Cc: Yang, Libin <libin.yang@intel.com>
Subject: RE: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
On Fri, 26 May 2017, "Wang, Quanxian" <quanxian.wang@intel.com> wrote:
> [Wang, Quanxian] in Ubuntu 17.04, we do audio testing on KBL/SKL/APL
> and more, the audio doesn't work on KBL specially, and other platform
> works fine. Even if with latest upstream kernel, but it works on 4.8
> kernel. Therefore It is a regression issue. After investigation, we
> found it is caused by commit
> "6014ac122ed081feca99217bc57b2e15c7fc1a51] drm/i915/audio: set proper
> N/M in modeset". Therefore I provided this patch.
If it's a regression, we need to backport the fix to stable kernels, and the patch needs annotation:
Fixes: 6014ac122ed0 ("drm/i915/audio: set proper N/M in modeset")
Cc: <stable@vger.kernel.org> # v4.10+
> After getting suggestion from you and Libin, we do more testing on 4K
> monitor for audio delay issue. Also talked with Libin why not use
> transcoder disable/enable process described in bspec, it will affect
> performance.
>
> This is the whole story. You can check LCK number 3791 in Intel JIRA
> about that.
Actually, I can't. And the commit message needs to have the explanation. I still do not know what the bug is specifically, or why Kabylake, and only Kabylake, needs this.
> [Wang, Quanxian] Basically if upstream could provide a reasonable
> patch, it will appreciate since you are expert in this area.
> Thanks for your understanding.
The patch is probably fine. But I can't invent an explanation if I don't know what the problem is.
BR,
Jani.
--
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
2017-05-26 21:36 ` Wang, Quanxian
@ 2017-05-29 8:29 ` Jani Nikula
2017-05-31 3:20 ` Wang, Quanxian
0 siblings, 1 reply; 9+ messages in thread
From: Jani Nikula @ 2017-05-29 8:29 UTC (permalink / raw)
To: Wang, Quanxian, intel-gfx
On Fri, 26 May 2017, "Wang, Quanxian" <quanxian.wang@intel.com> wrote:
> "The patch is probably fine. But I can't invent an explanation if I
> don't know what the problem is."
>
> @Jani @libin, is it possible for you to help contact Intel graphics
> hardware design engineer to get the reason why M/N doesn't work as you
> implemented in kernel code in Kabylake platform? I don't find good
> reason in bspec. Thanks.
How did you come up with the patch then? What made you try this?
BR,
Jani.
>
> -----Original Message-----
> From: Jani Nikula [mailto:jani.nikula@linux.intel.com]
> Sent: Friday, May 26, 2017 7:01 PM
> To: Wang, Quanxian <quanxian.wang@intel.com>; intel-gfx@lists.freedesktop.org
> Cc: Yang, Libin <libin.yang@intel.com>
> Subject: RE: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
>
> On Fri, 26 May 2017, "Wang, Quanxian" <quanxian.wang@intel.com> wrote:
>> [Wang, Quanxian] in Ubuntu 17.04, we do audio testing on KBL/SKL/APL
>> and more, the audio doesn't work on KBL specially, and other platform
>> works fine. Even if with latest upstream kernel, but it works on 4.8
>> kernel. Therefore It is a regression issue. After investigation, we
>> found it is caused by commit
>> "6014ac122ed081feca99217bc57b2e15c7fc1a51] drm/i915/audio: set proper
>> N/M in modeset". Therefore I provided this patch.
>
> If it's a regression, we need to backport the fix to stable kernels, and the patch needs annotation:
>
> Fixes: 6014ac122ed0 ("drm/i915/audio: set proper N/M in modeset")
> Cc: <stable@vger.kernel.org> # v4.10+
>
>> After getting suggestion from you and Libin, we do more testing on 4K
>> monitor for audio delay issue. Also talked with Libin why not use
>> transcoder disable/enable process described in bspec, it will affect
>> performance.
>>
>> This is the whole story. You can check LCK number 3791 in Intel JIRA
>> about that.
>
> Actually, I can't. And the commit message needs to have the explanation. I still do not know what the bug is specifically, or why Kabylake, and only Kabylake, needs this.
>
>> [Wang, Quanxian] Basically if upstream could provide a reasonable
>> patch, it will appreciate since you are expert in this area.
>> Thanks for your understanding.
>
> The patch is probably fine. But I can't invent an explanation if I don't know what the problem is.
>
>
> BR,
> Jani.
>
> --
> Jani Nikula, Intel Open Source Technology Center
--
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
2017-05-29 8:29 ` Jani Nikula
@ 2017-05-31 3:20 ` Wang, Quanxian
2017-12-08 0:41 ` Wang, Quanxian
0 siblings, 1 reply; 9+ messages in thread
From: Wang, Quanxian @ 2017-05-31 3:20 UTC (permalink / raw)
To: Jani Nikula, intel-gfx
-----Original Message-----
From: Jani Nikula [mailto:jani.nikula@linux.intel.com]
Sent: Monday, May 29, 2017 4:29 PM
To: Wang, Quanxian <quanxian.wang@intel.com>; intel-gfx@lists.freedesktop.org
Cc: Yang, Libin <libin.yang@intel.com>
Subject: RE: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
On Fri, 26 May 2017, "Wang, Quanxian" <quanxian.wang@intel.com> wrote:
> "The patch is probably fine. But I can't invent an explanation if I
> don't know what the problem is."
>
> @Jani @libin, is it possible for you to help contact Intel graphics
> hardware design engineer to get the reason why M/N doesn't work as you
> implemented in kernel code in Kabylake platform? I don't find good
> reason in bspec. Thanks.
How did you come up with the patch then? What made you try this?
[Wang, Quanxian] I am from OSV enabling team and responsible for Ubuntu enabling. 17.04 (kernel 4.10) is released, we will do full testing for all Intel platforms including KBL/SKL... With audio testing, we found this regression issue on KBL and find patch caused this regression. Compared with previous implementation, we use automatic M/N to have a try. It works.
BR,
Jani.
>
> -----Original Message-----
> From: Jani Nikula [mailto:jani.nikula@linux.intel.com]
> Sent: Friday, May 26, 2017 7:01 PM
> To: Wang, Quanxian <quanxian.wang@intel.com>;
> intel-gfx@lists.freedesktop.org
> Cc: Yang, Libin <libin.yang@intel.com>
> Subject: RE: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
>
> On Fri, 26 May 2017, "Wang, Quanxian" <quanxian.wang@intel.com> wrote:
>> [Wang, Quanxian] in Ubuntu 17.04, we do audio testing on KBL/SKL/APL
>> and more, the audio doesn't work on KBL specially, and other platform
>> works fine. Even if with latest upstream kernel, but it works on 4.8
>> kernel. Therefore It is a regression issue. After investigation, we
>> found it is caused by commit
>> "6014ac122ed081feca99217bc57b2e15c7fc1a51] drm/i915/audio: set proper
>> N/M in modeset". Therefore I provided this patch.
>
> If it's a regression, we need to backport the fix to stable kernels, and the patch needs annotation:
>
> Fixes: 6014ac122ed0 ("drm/i915/audio: set proper N/M in modeset")
> Cc: <stable@vger.kernel.org> # v4.10+
>
>> After getting suggestion from you and Libin, we do more testing on 4K
>> monitor for audio delay issue. Also talked with Libin why not use
>> transcoder disable/enable process described in bspec, it will affect
>> performance.
>>
>> This is the whole story. You can check LCK number 3791 in Intel JIRA
>> about that.
>
> Actually, I can't. And the commit message needs to have the explanation. I still do not know what the bug is specifically, or why Kabylake, and only Kabylake, needs this.
>
>> [Wang, Quanxian] Basically if upstream could provide a reasonable
>> patch, it will appreciate since you are expert in this area.
>> Thanks for your understanding.
>
> The patch is probably fine. But I can't invent an explanation if I don't know what the problem is.
>
>
> BR,
> Jani.
>
> --
> Jani Nikula, Intel Open Source Technology Center
--
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
2017-05-31 3:20 ` Wang, Quanxian
@ 2017-12-08 0:41 ` Wang, Quanxian
0 siblings, 0 replies; 9+ messages in thread
From: Wang, Quanxian @ 2017-12-08 0:41 UTC (permalink / raw)
To: Jani Nikula, intel-gfx
Hi, Jani
I have created a Bugzilla in free desktop for tracking.
https://bugs.freedesktop.org/show_bug.cgi?id=104093
Appreciate find audio expert could help us address root cause.
Thank you.
Quanxian
-----Original Message-----
From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On Behalf Of Wang, Quanxian
Sent: Wednesday, May 31, 2017 11:21 AM
To: Jani Nikula <jani.nikula@linux.intel.com>; intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
-----Original Message-----
From: Jani Nikula [mailto:jani.nikula@linux.intel.com]
Sent: Monday, May 29, 2017 4:29 PM
To: Wang, Quanxian <quanxian.wang@intel.com>; intel-gfx@lists.freedesktop.org
Cc: Yang, Libin <libin.yang@intel.com>
Subject: RE: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
On Fri, 26 May 2017, "Wang, Quanxian" <quanxian.wang@intel.com> wrote:
> "The patch is probably fine. But I can't invent an explanation if I
> don't know what the problem is."
>
> @Jani @libin, is it possible for you to help contact Intel graphics
> hardware design engineer to get the reason why M/N doesn't work as you
> implemented in kernel code in Kabylake platform? I don't find good
> reason in bspec. Thanks.
How did you come up with the patch then? What made you try this?
[Wang, Quanxian] I am from OSV enabling team and responsible for Ubuntu enabling. 17.04 (kernel 4.10) is released, we will do full testing for all Intel platforms including KBL/SKL... With audio testing, we found this regression issue on KBL and find patch caused this regression. Compared with previous implementation, we use automatic M/N to have a try. It works.
BR,
Jani.
>
> -----Original Message-----
> From: Jani Nikula [mailto:jani.nikula@linux.intel.com]
> Sent: Friday, May 26, 2017 7:01 PM
> To: Wang, Quanxian <quanxian.wang@intel.com>;
> intel-gfx@lists.freedesktop.org
> Cc: Yang, Libin <libin.yang@intel.com>
> Subject: RE: [PATCH] Defined NM doesn't work on KBL and uses automatic N/M.
>
> On Fri, 26 May 2017, "Wang, Quanxian" <quanxian.wang@intel.com> wrote:
>> [Wang, Quanxian] in Ubuntu 17.04, we do audio testing on KBL/SKL/APL
>> and more, the audio doesn't work on KBL specially, and other platform
>> works fine. Even if with latest upstream kernel, but it works on 4.8
>> kernel. Therefore It is a regression issue. After investigation, we
>> found it is caused by commit
>> "6014ac122ed081feca99217bc57b2e15c7fc1a51] drm/i915/audio: set proper
>> N/M in modeset". Therefore I provided this patch.
>
> If it's a regression, we need to backport the fix to stable kernels, and the patch needs annotation:
>
> Fixes: 6014ac122ed0 ("drm/i915/audio: set proper N/M in modeset")
> Cc: <stable@vger.kernel.org> # v4.10+
>
>> After getting suggestion from you and Libin, we do more testing on 4K
>> monitor for audio delay issue. Also talked with Libin why not use
>> transcoder disable/enable process described in bspec, it will affect
>> performance.
>>
>> This is the whole story. You can check LCK number 3791 in Intel JIRA
>> about that.
>
> Actually, I can't. And the commit message needs to have the explanation. I still do not know what the bug is specifically, or why Kabylake, and only Kabylake, needs this.
>
>> [Wang, Quanxian] Basically if upstream could provide a reasonable
>> patch, it will appreciate since you are expert in this area.
>> Thanks for your understanding.
>
> The patch is probably fine. But I can't invent an explanation if I don't know what the problem is.
>
>
> BR,
> Jani.
>
> --
> Jani Nikula, Intel Open Source Technology Center
--
Jani Nikula, Intel Open Source Technology Center
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^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2017-12-08 0:50 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-05-26 6:07 [PATCH] Defined NM doesn't work on KBL and uses automatic N/M Quanxian Wang
2017-05-26 6:27 ` ✓ Fi.CI.BAT: success for " Patchwork
2017-05-26 8:31 ` [PATCH] " Jani Nikula
2017-05-26 9:52 ` Wang, Quanxian
2017-05-26 11:00 ` Jani Nikula
2017-05-26 21:36 ` Wang, Quanxian
2017-05-29 8:29 ` Jani Nikula
2017-05-31 3:20 ` Wang, Quanxian
2017-12-08 0:41 ` Wang, Quanxian
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