Skip to contentSkip to conversation

ALSA: hda - PCH HDA controller not controlled by i915 power

PATCH In review [email protected] 3 participants 10 messages Jun 9, 2015 – Jun 10, 2015 Sound

lore
Share & tools
lore

[email protected]

author
#0 lore raw

PATCH 1/1 ALSA: hda - PCH HDA controller not controlled by i915 power

From: Libin Yang <[email protected]>

On some Intel platforms, the HDMI codec is connected to PCH HDA controller. In this case, AZX_DCAPS_I915_POWERWELL is set and the i915 power well failure should not block the hda controller initialization.

Signed-off-by Libin Yang <[email protected]>
---
 sound/hda/hdac_i915.c     |  6 +++---
 sound/pci/hda/hda_intel.c | 11 +++++++++--
 2 files changed, 12 insertions(+), 5 deletions(-)
sound/hda/hdac_i915.c +3 -3
index cb78c25..4f4036a 100644
@@ -27,7 +27,7 @@ int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable)
 {
 	struct i915_audio_component *acomp = bus->audio_component;
 
-	if (!acomp->ops)
+	if (!acomp || !acomp->ops)
 		return -ENODEV;
 
 	if (!acomp->ops->codec_wake_override) {

@@ -49,7 +49,7 @@ int snd_hdac_display_power(struct hdac_bus *bus, bool enable)
 {
 	struct i915_audio_component *acomp = bus->audio_component;
 
-	if (!acomp->ops)
+	if (!acomp || !acomp->ops)
 		return -ENODEV;
 
 	dev_dbg(bus->dev, "display power %s\n",

@@ -72,7 +72,7 @@ int snd_hdac_get_display_clk(struct hdac_bus *bus)
 {
 	struct i915_audio_component *acomp = bus->audio_component;
 
-	if (!acomp->ops)
+	if (!acomp || !acomp->ops)
 		return -ENODEV;
 
 	return acomp->ops->get_cdclk_freq(acomp->dev);
sound/pci/hda/hda_intel.c +9 -2
index 7933fb0..775e020 100644
@@ -1986,14 +1986,21 @@ static int azx_probe_continue(struct azx *chip)
 			hda->need_i915_power = 1;
 
 		err = snd_hdac_i915_init(bus);
+		/* if controller is located in powerwell,
+		 * the initialization should be stopped.
+		 * if only codec is located in powerwell,
+		 * the hd audio is still ok for analog audio
+		 */
 		if (err < 0)
-			goto i915_power_fail;
+			if (hda->need_i915_power)
+				goto i915_power_fail;
 
 		err = snd_hdac_display_power(bus, true);
 		if (err < 0) {
 			dev_err(chip->card->dev,
 				"Cannot turn on display power on i915\n");
-			goto i915_power_fail;
+			if (hda->need_i915_power)
+				goto i915_power_fail;
 		}
 	}
Signature · 1 line
1.9.1
#1 lore raw

At Tue, 9 Jun 2015 14:05:18 +0800,

Quoted 9 lines · [email protected] wrote:

From: Libin Yang <[email protected]>

On some Intel platforms, the HDMI codec is connected to PCH HDA controller. In this case, AZX_DCAPS_I915_POWERWELL is set and the i915 power well failure should not block the hda controller initialization.

Signed-off-by Libin Yang <[email protected]>

Is this fix needed for 4.1, or it's only for 4.2?
I vaguely remember of a bug report. If there is any relevant bug report, please give the link, too.

Takashi

Quoted 67 lines
---
 sound/hda/hdac_i915.c     |  6 +++---
 sound/pci/hda/hda_intel.c | 11 +++++++++--
 2 files changed, 12 insertions(+), 5 deletions(-)
sound/hda/hdac_i915.c +3 -3
index cb78c25..4f4036a 100644
@@ -27,7 +27,7 @@ int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable)
 {
 	struct i915_audio_component *acomp = bus->audio_component;
 
-	if (!acomp->ops)
+	if (!acomp || !acomp->ops)
 		return -ENODEV;
 
 	if (!acomp->ops->codec_wake_override) {

@@ -49,7 +49,7 @@ int snd_hdac_display_power(struct hdac_bus *bus, bool enable)
 {
 	struct i915_audio_component *acomp = bus->audio_component;
 
-	if (!acomp->ops)
+	if (!acomp || !acomp->ops)
 		return -ENODEV;
 
 	dev_dbg(bus->dev, "display power %s\n",

@@ -72,7 +72,7 @@ int snd_hdac_get_display_clk(struct hdac_bus *bus)
 {
 	struct i915_audio_component *acomp = bus->audio_component;
 
-	if (!acomp->ops)
+	if (!acomp || !acomp->ops)
 		return -ENODEV;
 
 	return acomp->ops->get_cdclk_freq(acomp->dev);
sound/pci/hda/hda_intel.c +9 -2
index 7933fb0..775e020 100644
@@ -1986,14 +1986,21 @@ static int azx_probe_continue(struct azx *chip)
 			hda->need_i915_power = 1;
 
 		err = snd_hdac_i915_init(bus);
+		/* if controller is located in powerwell,
+		 * the initialization should be stopped.
+		 * if only codec is located in powerwell,
+		 * the hd audio is still ok for analog audio
+		 */
 		if (err < 0)
-			goto i915_power_fail;
+			if (hda->need_i915_power)
+				goto i915_power_fail;
 
 		err = snd_hdac_display_power(bus, true);
 		if (err < 0) {
 			dev_err(chip->card->dev,
 				"Cannot turn on display power on i915\n");
-			goto i915_power_fail;
+			if (hda->need_i915_power)
+				goto i915_power_fail;
 		}
 	}
Signature · 1 line
1.9.1
#2 lore raw
Quoted 5 lines · Takashi Iwai

At Tue, 9 Jun 2015 14:05:18 +0800,

Quoted 3 lines · [email protected] wrote:

From: Libin Yang <[email protected]>

Quoted 8 lines
Quoted 6 lines

On some Intel platforms, the HDMI codec is connected to PCH HDA controller. In this case, AZX_DCAPS_I915_POWERWELL is set and the i915 power well failure should not block the hda controller initialization.

Signed-off-by Libin Yang <[email protected]>

Is this fix needed for 4.1, or it's only for 4.2?

It's a bug fix, and as such should go to all kernels, even with cc to stable. That said, it mainly concerns Skylake, so kernels that don't support Skylake would not need a backport.

Quoted 2 lines

I vaguely remember of a bug report. If there is any relevant bug report, please give the link, too.

I think this was raised to Intel by us. The use case is when the integrated GPU is disabled and a discrete GPU is used. In this case the i915 module fails to load. If then the HDMI and analog codec are both on the same controller, the entire controller fails instead of just the HDMI codec.

I'll see if I can get the patch tested ASAP.

Quoted 76 lines

Takashi

Quoted 65 lines
---
  sound/hda/hdac_i915.c     |  6 +++---
  sound/pci/hda/hda_intel.c | 11 +++++++++--
  2 files changed, 12 insertions(+), 5 deletions(-)
sound/hda/hdac_i915.c +3 -3
index cb78c25..4f4036a 100644
@@ -27,7 +27,7 @@ int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable)
  {
  	struct i915_audio_component *acomp = bus->audio_component;
 
-	if (!acomp->ops)
+	if (!acomp || !acomp->ops)
  		return -ENODEV;
 
  	if (!acomp->ops->codec_wake_override) {

@@ -49,7 +49,7 @@ int snd_hdac_display_power(struct hdac_bus *bus, bool enable)
  {
  	struct i915_audio_component *acomp = bus->audio_component;
 
-	if (!acomp->ops)
+	if (!acomp || !acomp->ops)
  		return -ENODEV;
 
  	dev_dbg(bus->dev, "display power %s\n",

@@ -72,7 +72,7 @@ int snd_hdac_get_display_clk(struct hdac_bus *bus)
  {
  	struct i915_audio_component *acomp = bus->audio_component;
 
-	if (!acomp->ops)
+	if (!acomp || !acomp->ops)
  		return -ENODEV;
 
  	return acomp->ops->get_cdclk_freq(acomp->dev);
sound/pci/hda/hda_intel.c +9 -3
index 7933fb0..775e020 100644
@@ -1986,14 +1986,21 @@ static int azx_probe_continue(struct azx *chip)
  			hda->need_i915_power = 1;
 
  		err = snd_hdac_i915_init(bus);
+		/* if controller is located in powerwell,
+		 * the initialization should be stopped.
+		 * if only codec is located in powerwell,
+		 * the hd audio is still ok for analog audio
+		 */
  		if (err < 0)
-			goto i915_power_fail;
+			if (hda->need_i915_power)
+				goto i915_power_fail;
 
  		err = snd_hdac_display_power(bus, true);
  		if (err < 0) {
  			dev_err(chip->card->dev,
  				"Cannot turn on display power on i915\n");
-			goto i915_power_fail;
+			if (hda->need_i915_power)
+				goto i915_power_fail;
  		}
  	}
 
--
Quoted 2 lines

1.9.1

_______________________________________________
Alsa-devel mailing list
[email protected]
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

Signature · 2 lines
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic
#3 lore raw

At Tue, 09 Jun 2015 08:46:35 +0200,

Quoted 14 lines · David Henningsson
Quoted 10 lines · Takashi Iwai

At Tue, 9 Jun 2015 14:05:18 +0800,

Quoted 8 lines · [email protected] wrote:

From: Libin Yang <[email protected]>

On some Intel platforms, the HDMI codec is connected to PCH HDA controller. In this case, AZX_DCAPS_I915_POWERWELL is set and the i915 power well failure should not block the hda controller initialization.

Quoted 7 lines
Quoted 3 lines
Quoted 1 line
Signed-off-by Libin Yang <[email protected]>

Is this fix needed for 4.1, or it's only for 4.2?

It's a bug fix, and as such should go to all kernels, even with cc to stable. That said, it mainly concerns Skylake, so kernels that don't support Skylake would not need a backport.

The patch can't be applied even to 4.1 as is because of the code structure change. So, Cc to stable doesn't work, in anyway.

Quoted 10 lines
Quoted 2 lines

I vaguely remember of a bug report. If there is any relevant bug report, please give the link, too.

I think this was raised to Intel by us. The use case is when the integrated GPU is disabled and a discrete GPU is used. In this case the i915 module fails to load. If then the HDMI and analog codec are both on the same controller, the entire controller fails instead of just the HDMI codec.

I'll see if I can get the patch tested ASAP.

OK, the bug seems needed for 4.1 and earlier. But Libin's patch is only for 4.2. And even worse, backporting this isn't straightforward due to the lack of need_i915_power field. Hmm.

I think we can make it easier by just allowing to continue the probe. A totally untested patch for 4.1 is below.

thanks,

Takashi

---

sound/pci/hda/hda_intel.c +12 -2
index fea198c58196..3903a62ce1e8 100644
@@ -340,6 +340,11 @@ enum {
 #define use_vga_switcheroo(chip)	0
 #endif
 
+#define CONTROLLER_IN_GPU(pci) (((pci)->device == 0x0a0c) || \
+					((pci)->device == 0x0c0c) || \
+					((pci)->device == 0x0d0c) || \
+					((pci)->device == 0x160c))
+
 static char *driver_short_names[] = {
 	[AZX_DRIVER_ICH] = "HDA Intel",
 	[AZX_DRIVER_PCH] = "HDA Intel PCH",

@@ -1854,8 +1859,12 @@ static int azx_probe_continue(struct azx *chip)
 	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
 #ifdef CONFIG_SND_HDA_I915
 		err = hda_i915_init(hda);
-		if (err < 0)
-			goto out_free;
+		if (err < 0) {
+			if (CONTROLLER_IN_GPU(pci))
+				goto out_free;
+			else
+				goto skip_i915;
+		}
 		err = hda_display_power(hda, true);
 		if (err < 0) {
 			dev_err(chip->card->dev,

@@ -1865,6 +1874,7 @@ static int azx_probe_continue(struct azx *chip)
 #endif
 	}
 
+ skip_i915:
 	err = azx_first_init(chip);
 	if (err < 0)
 		goto out_free;
author
#4 lore raw

Hi Takashi,

Quoted 36 lines

-----Original Message-----
From: Takashi Iwai [mailto:[email protected]]
Sent: Tuesday, June 09, 2015 4:30 PM
To: David Henningsson
Cc: Yang, Libin; [email protected]
Subject: Re: [alsa-devel] [PATCH] ALSA: hda - PCH HDA controller not controlled by i915 power

At Tue, 09 Jun 2015 08:46:35 +0200,

Quoted 10 lines · David Henningsson
Quoted 6 lines · Takashi Iwai

At Tue, 9 Jun 2015 14:05:18 +0800,

Quoted 4 lines · [email protected] wrote:

From: Libin Yang <[email protected]>

On some Intel platforms, the HDMI codec is connected to PCH

HDA

Quoted 11 lines
Quoted 7 lines
Quoted 5 lines

controller. In this case, AZX_DCAPS_I915_POWERWELL is set and the i915 power well failure should not block the hda controller initialization.

Signed-off-by Libin Yang <[email protected]>

Is this fix needed for 4.1, or it's only for 4.2?

It's a bug fix, and as such should go to all kernels, even with cc to stable. That said, it mainly concerns Skylake, so kernels that don't support Skylake would not need a backport.

The patch can't be applied even to 4.1 as is because of the code structure change. So, Cc to stable doesn't work, in anyway.

Quoted 10 lines
Quoted 5 lines
Quoted 2 lines

I vaguely remember of a bug report. If there is any relevant bug report, please give the link, too.

I think this was raised to Intel by us. The use case is when the integrated GPU is disabled and a discrete GPU is used. In this case

the

Quoted 1 line

i915 module fails to load. If then the HDMI and analog codec are both

on

Quoted 2 lines

the same controller, the entire controller fails instead of just the HDMI codec.

I can't find the bug number, maybe David can help.

BTW: Not only SKL but also other platforms that controller is not in Powerwell while the controller connects with HDMI codec will meet such issue, like BSW.

Quoted 9 lines
Quoted 2 lines

I'll see if I can get the patch tested ASAP.

OK, the bug seems needed for 4.1 and earlier. But Libin's patch is only for 4.2. And even worse, backporting this isn't straightforward due to the lack of need_i915_power field. Hmm.

I think we can make it easier by just allowing to continue the probe. A totally untested patch for 4.1 is below.

Thanks for your help on this. So this patch will be merged or we will wait for 4.2 to merge the patch?

Quoted 48 lines

thanks,

Takashi

---

sound/pci/hda/hda_intel.c +11 -2
index fea198c58196..3903a62ce1e8 100644
@@ -340,6 +340,11 @@ enum {
 #define use_vga_switcheroo(chip)	0
 #endif
 
+#define CONTROLLER_IN_GPU(pci) (((pci)->device == 0x0a0c) || \
+					((pci)->device == 0x0c0c) || \
+					((pci)->device == 0x0d0c) || \
+					((pci)->device == 0x160c))
+
 static char *driver_short_names[] = {
 	[AZX_DRIVER_ICH] = "HDA Intel",
 	[AZX_DRIVER_PCH] = "HDA Intel PCH",

@@ -1854,8 +1859,12 @@ static int azx_probe_continue(struct azx
 *chip)
 	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
 #ifdef CONFIG_SND_HDA_I915
 		err = hda_i915_init(hda);
-		if (err < 0)
-			goto out_free;
+		if (err < 0) {
+			if (CONTROLLER_IN_GPU(pci))
+				goto out_free;
+			else
+				goto skip_i915;
+		}
 		err = hda_display_power(hda, true);
 		if (err < 0) {
sound/pci/hda/hda_intel.c +1 -0
 			dev_err(chip->card->dev,

@@ -1865,6 +1874,7 @@ static int azx_probe_continue(struct azx
 *chip)
 #endif
 	}
 
+ skip_i915:
 	err = azx_first_init(chip);
 	if (err < 0)

goto out_free;

#5 lore raw

At Tue, 9 Jun 2015 08:43:44 +0000,

Quoted 63 lines · Libin

Hi Takashi,

Quoted 36 lines

-----Original Message-----
From: Takashi Iwai [mailto:[email protected]]
Sent: Tuesday, June 09, 2015 4:30 PM
To: David Henningsson
Cc: Yang, Libin; [email protected]
Subject: Re: [alsa-devel] [PATCH] ALSA: hda - PCH HDA controller not controlled by i915 power

At Tue, 09 Jun 2015 08:46:35 +0200,

Quoted 10 lines · David Henningsson
Quoted 6 lines · Takashi Iwai

At Tue, 9 Jun 2015 14:05:18 +0800,

Quoted 4 lines · [email protected] wrote:

From: Libin Yang <[email protected]>

On some Intel platforms, the HDMI codec is connected to PCH

HDA

Quoted 11 lines
Quoted 7 lines
Quoted 5 lines

controller. In this case, AZX_DCAPS_I915_POWERWELL is set and the i915 power well failure should not block the hda controller initialization.

Signed-off-by Libin Yang <[email protected]>

Is this fix needed for 4.1, or it's only for 4.2?

It's a bug fix, and as such should go to all kernels, even with cc to stable. That said, it mainly concerns Skylake, so kernels that don't support Skylake would not need a backport.

The patch can't be applied even to 4.1 as is because of the code structure change. So, Cc to stable doesn't work, in anyway.

Quoted 10 lines
Quoted 5 lines
Quoted 2 lines

I vaguely remember of a bug report. If there is any relevant bug report, please give the link, too.

I think this was raised to Intel by us. The use case is when the integrated GPU is disabled and a discrete GPU is used. In this case

the

Quoted 1 line

i915 module fails to load. If then the HDMI and analog codec are both

on

Quoted 2 lines

the same controller, the entire controller fails instead of just the HDMI codec.

I can't find the bug number, maybe David can help.

BTW: Not only SKL but also other platforms that controller is not in Powerwell while the controller connects with HDMI codec will meet such issue, like BSW.

Quoted 7 lines
Quoted 2 lines

I'll see if I can get the patch tested ASAP.

OK, the bug seems needed for 4.1 and earlier. But Libin's patch is only for 4.2. And even worse, backporting this isn't straightforward due to the lack of need_i915_power field. Hmm.

Quoted 5 lines
Quoted 2 lines

I think we can make it easier by just allowing to continue the probe. A totally untested patch for 4.1 is below.

Thanks for your help on this. So this patch will be merged or we will wait for 4.2 to merge the patch?

Let's see whether it works as expected.
If this works for 4.1, we can merge back to 4.2 together with additional NULL checks in hdac_i915.c.

Takashi

#6 lore raw
In reply to Takashi Iwai
Quoted 36 lines · Takashi Iwai

At Tue, 09 Jun 2015 08:46:35 +0200,

Quoted 14 lines · David Henningsson
Quoted 10 lines · Takashi Iwai

At Tue, 9 Jun 2015 14:05:18 +0800,

Quoted 8 lines · [email protected] wrote:

From: Libin Yang <[email protected]>

On some Intel platforms, the HDMI codec is connected to PCH HDA controller. In this case, AZX_DCAPS_I915_POWERWELL is set and the i915 power well failure should not block the hda controller initialization.

Quoted 7 lines
Quoted 3 lines
Quoted 1 line
Signed-off-by Libin Yang <[email protected]>

Is this fix needed for 4.1, or it's only for 4.2?

It's a bug fix, and as such should go to all kernels, even with cc to stable. That said, it mainly concerns Skylake, so kernels that don't support Skylake would not need a backport.

The patch can't be applied even to 4.1 as is because of the code structure change. So, Cc to stable doesn't work, in anyway.

Quoted 9 lines
Quoted 2 lines

I vaguely remember of a bug report. If there is any relevant bug report, please give the link, too.

I think this was raised to Intel by us. The use case is when the integrated GPU is disabled and a discrete GPU is used. In this case the i915 module fails to load. If then the HDMI and analog codec are both on the same controller, the entire controller fails instead of just the HDMI codec.

Quoted 8 lines
Quoted 1 line

I'll see if I can get the patch tested ASAP.

OK, the bug seems needed for 4.1 and earlier. But Libin's patch is only for 4.2. And even worse, backporting this isn't straightforward due to the lack of need_i915_power field. Hmm.

I think we can make it easier by just allowing to continue the probe. A totally untested patch for 4.1 is below.

As part of the wider discussion, I think we could continue instead of failing also on Haswell and Broadwell. This is to some degree hypothetical, but if the i915 module does not load for some reason, then the i915 module would not turn the power well off either, so it remains on the entire time (and then audio could potentially work).

Signature · 2 lines
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic
#7 lore raw

At Tue, 09 Jun 2015 10:51:19 +0200,

Quoted 46 lines · David Henningsson
Quoted 42 lines · Takashi Iwai

At Tue, 09 Jun 2015 08:46:35 +0200,

Quoted 14 lines · David Henningsson
Quoted 10 lines · Takashi Iwai

At Tue, 9 Jun 2015 14:05:18 +0800,

Quoted 8 lines · [email protected] wrote:

From: Libin Yang <[email protected]>

On some Intel platforms, the HDMI codec is connected to PCH HDA controller. In this case, AZX_DCAPS_I915_POWERWELL is set and the i915 power well failure should not block the hda controller initialization.

Quoted 7 lines
Quoted 3 lines
Quoted 1 line
Signed-off-by Libin Yang <[email protected]>

Is this fix needed for 4.1, or it's only for 4.2?

It's a bug fix, and as such should go to all kernels, even with cc to stable. That said, it mainly concerns Skylake, so kernels that don't support Skylake would not need a backport.

The patch can't be applied even to 4.1 as is because of the code structure change. So, Cc to stable doesn't work, in anyway.

Quoted 10 lines
Quoted 2 lines

I vaguely remember of a bug report. If there is any relevant bug report, please give the link, too.

I think this was raised to Intel by us. The use case is when the integrated GPU is disabled and a discrete GPU is used. In this case the i915 module fails to load. If then the HDMI and analog codec are both on the same controller, the entire controller fails instead of just the HDMI codec.

I'll see if I can get the patch tested ASAP.

OK, the bug seems needed for 4.1 and earlier. But Libin's patch is only for 4.2. And even worse, backporting this isn't straightforward due to the lack of need_i915_power field. Hmm.

Quoted 8 lines
Quoted 2 lines

I think we can make it easier by just allowing to continue the probe. A totally untested patch for 4.1 is below.

As part of the wider discussion, I think we could continue instead of failing also on Haswell and Broadwell. This is to some degree hypothetical, but if the i915 module does not load for some reason, then the i915 module would not turn the power well off either, so it remains on the entire time (and then audio could potentially work).

Without graphics HDMI/DP never works, so practically it's useless. The problem can be reproduced easily by passing nomodeset boot option.

OTOH, it'd simplify the change, and this was indeed my initial patch before posting. Then I thought this might lead to a regression; a non-working HDMI/DP sound card appears while it wasn't before. So I added the check of HSW/BDW.

Meanwhile, nomodeset or failing i915 is a more or less special situation, so we might not consider about this behavior change so much, and take rather for the code simplicity.

Comments?

Takashi

author
#8 lore raw

+ Mengdong

Hi Takashi & David,

Quoted 80 lines

-----Original Message-----
From: Takashi Iwai [mailto:[email protected]]
Sent: Tuesday, June 09, 2015 5:06 PM
To: David Henningsson
Cc: Yang, Libin; [email protected]
Subject: Re: [alsa-devel] [PATCH] ALSA: hda - PCH HDA controller not controlled by i915 power

At Tue, 09 Jun 2015 10:51:19 +0200,

Quoted 9 lines · David Henningsson
Quoted 5 lines · Takashi Iwai

At Tue, 09 Jun 2015 08:46:35 +0200,

Quoted 3 lines · David Henningsson
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines · Takashi Iwai
Quoted 6 lines

At Tue, 9 Jun 2015 14:05:18 +0800,

Quoted 4 lines · [email protected] wrote:

From: Libin Yang <[email protected]>

On some Intel platforms, the HDMI codec is connected to PCH

HDA

Quoted 1 line
Quoted 1 line
Quoted 1 line
Quoted 1 line
Quoted 1 line

controller. In this case, AZX_DCAPS_I915_POWERWELL is set

and

Quoted 11 lines
Quoted 11 lines
Quoted 10 lines
Quoted 6 lines
Quoted 4 lines

the i915 power well failure should not block the hda controller initialization.

Signed-off-by Libin Yang <[email protected]>

Is this fix needed for 4.1, or it's only for 4.2?

It's a bug fix, and as such should go to all kernels, even with cc to stable. That said, it mainly concerns Skylake, so kernels that don't support Skylake would not need a backport.

Quoted 8 lines
Quoted 8 lines

The patch can't be applied even to 4.1 as is because of the code structure change. So, Cc to stable doesn't work, in anyway.

Quoted 5 lines
Quoted 2 lines

I vaguely remember of a bug report. If there is any relevant bug report, please give the link, too.

I think this was raised to Intel by us. The use case is when the integrated GPU is disabled and a discrete GPU is used. In this case

the

Quoted 1 line
Quoted 1 line
Quoted 1 line

i915 module fails to load. If then the HDMI and analog codec are

both on

Quoted 9 lines
Quoted 9 lines
Quoted 4 lines

the same controller, the entire controller fails instead of just the HDMI codec.

I'll see if I can get the patch tested ASAP.

OK, the bug seems needed for 4.1 and earlier. But Libin's patch is only for 4.2. And even worse, backporting this isn't straightforward due to the lack of need_i915_power field. Hmm.

Quoted 6 lines
Quoted 2 lines

I think we can make it easier by just allowing to continue the probe. A totally untested patch for 4.1 is below.

As part of the wider discussion, I think we could continue instead of failing also on Haswell and Broadwell. This is to some degree hypothetical, but if the i915 module does not load for some reason,

then

Quoted 1 line

the i915 module would not turn the power well off either, so it

remains

Quoted 1 line

on the entire time (and then audio could potentially work).

Without graphics HDMI/DP never works, so practically it's useless. The problem can be reproduced easily by passing nomodeset boot option.

OTOH, it'd simplify the change, and this was indeed my initial patch before posting. Then I thought this might lead to a regression; a non-working HDMI/DP sound card appears while it wasn't before. So I added the check of HSW/BDW.

Quoted 5 lines

Meanwhile, nomodeset or failing i915 is a more or less special situation, so we might not consider about this behavior change so much, and take rather for the code simplicity.

Comments?

Yes, HDMI/DP depends on gfx.

BDW/HSW has 2 controllers: one is in power well, the other is not. The one in powerwell connects HDMI/DP codec.
The one in PCH connects analog codec.

SKL/BSW/BYT has one controller and it connects both HDMI/DP codec and analog codec.

So we get the conclusion:
1. whatever power well is turned on, BDW/HSW PCH HDA controller will work.
2. If power well is turned off, BDW/HSW HDA controller in gfx will not work.
3. if power well is turned off, SKL/BSW/BYT controller will work (analog audio will use it), but HDMI/DP audio will not work.

Quoted 3 lines

Takashi

#9 lore raw
In reply to Takashi Iwai

At Tue, 09 Jun 2015 11:06:09 +0200,

Quoted 67 lines · Takashi Iwai

At Tue, 09 Jun 2015 10:51:19 +0200,

Quoted 46 lines · David Henningsson
Quoted 42 lines · Takashi Iwai

At Tue, 09 Jun 2015 08:46:35 +0200,

Quoted 14 lines · David Henningsson
Quoted 10 lines · Takashi Iwai

At Tue, 9 Jun 2015 14:05:18 +0800,

Quoted 8 lines · [email protected] wrote:

From: Libin Yang <[email protected]>

On some Intel platforms, the HDMI codec is connected to PCH HDA controller. In this case, AZX_DCAPS_I915_POWERWELL is set and the i915 power well failure should not block the hda controller initialization.

Quoted 7 lines
Quoted 3 lines
Quoted 1 line
Signed-off-by Libin Yang <[email protected]>

Is this fix needed for 4.1, or it's only for 4.2?

It's a bug fix, and as such should go to all kernels, even with cc to stable. That said, it mainly concerns Skylake, so kernels that don't support Skylake would not need a backport.

The patch can't be applied even to 4.1 as is because of the code structure change. So, Cc to stable doesn't work, in anyway.

Quoted 10 lines
Quoted 2 lines

I vaguely remember of a bug report. If there is any relevant bug report, please give the link, too.

I think this was raised to Intel by us. The use case is when the integrated GPU is disabled and a discrete GPU is used. In this case the i915 module fails to load. If then the HDMI and analog codec are both on the same controller, the entire controller fails instead of just the HDMI codec.

I'll see if I can get the patch tested ASAP.

OK, the bug seems needed for 4.1 and earlier. But Libin's patch is only for 4.2. And even worse, backporting this isn't straightforward due to the lack of need_i915_power field. Hmm.

Quoted 8 lines
Quoted 2 lines

I think we can make it easier by just allowing to continue the probe. A totally untested patch for 4.1 is below.

As part of the wider discussion, I think we could continue instead of failing also on Haswell and Broadwell. This is to some degree hypothetical, but if the i915 module does not load for some reason, then the i915 module would not turn the power well off either, so it remains on the entire time (and then audio could potentially work).

Without graphics HDMI/DP never works, so practically it's useless. The problem can be reproduced easily by passing nomodeset boot option.

OTOH, it'd simplify the change, and this was indeed my initial patch before posting. Then I thought this might lead to a regression; a non-working HDMI/DP sound card appears while it wasn't before. So I added the check of HSW/BDW.

Quoted 5 lines

Meanwhile, nomodeset or failing i915 is a more or less special situation, so we might not consider about this behavior change so much, and take rather for the code simplicity.

Comments?

After sleeping, I changed my mind: now I vote for simplicity.

I'm going to post a patch series, one for 4.1 and another for 4.2 in addition.

Takashi