Re: [PATCH 2/2 V4] ALSA: hda - Add power-welll support for haswell HDA

["Wang, Xingchao" <xingchao.wang@intel.com>]

> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai@suse.de]
> Sent: Tuesday, May 21, 2013 3:19 PM
> To: Wang Xingchao
> Cc: daniel@ffwll.ch; Girdwood, Liam R; david.henningsson@canonical.com; Lin,
> Mengdong; Li, Jocelyn; alsa-devel@alsa-project.org;
> intel-gfx@lists.freedesktop.org; Barnes, Jesse; Zanoni, Paulo R; Wang,
> Xingchao
> Subject: Re: [PATCH 2/2 V4] ALSA: hda - Add power-welll support for haswell
> HDA
> 
> At Mon, 20 May 2013 19:26:58 +0800,
> Wang Xingchao wrote:
> >
> > For Intel Haswell chip, HDA controller and codec have power well
> > dependency from GPU side. This patch added support to request/release
> > power well in audio driver. Power save feature should be enabled to
> > get runtime power saving.
> >
> > Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
> > ---
> >  sound/pci/hda/Kconfig     |   10 ++++++
> >  sound/pci/hda/Makefile    |    3 ++
> >  sound/pci/hda/hda_i915.c  |   75
> +++++++++++++++++++++++++++++++++++++++++++++
> >  sound/pci/hda/hda_i915.h  |   35 +++++++++++++++++++++
> >  sound/pci/hda/hda_intel.c |   41 +++++++++++++++++++++++--
> >  5 files changed, 161 insertions(+), 3 deletions(-)  create mode
> > 100644 sound/pci/hda/hda_i915.c  create mode 100644
> > sound/pci/hda/hda_i915.h
> >
> > diff --git a/sound/pci/hda/Kconfig b/sound/pci/hda/Kconfig index
> > 80a7d44..c5a872c 100644
> > --- a/sound/pci/hda/Kconfig
> > +++ b/sound/pci/hda/Kconfig
> > @@ -152,6 +152,16 @@ config SND_HDA_CODEC_HDMI
> >  	  snd-hda-codec-hdmi.
> >  	  This module is automatically loaded at probing.
> >
> > +config SND_HDA_I915
> > +	bool "Build Display HD-audio controller/codec power well support for i915
> cards"
> > +	depends on DRM_I915
> > +	help
> > +	  Say Y here to include full HDMI and DisplayPort HD-audio
> controller/codec
> > +	  power-well support for Intel Haswell graphics cards based on the i915
> driver.
> > +
> > +	  Note that this option must be enabled for Intel Haswell C+ stepping
> machines, otherwise
> > +	  the GPU audio controller/codecs will not be initialized or damaged when
> exit from S3 mode.
> > +
> >  config SND_HDA_CODEC_CIRRUS
> >  	bool "Build Cirrus Logic codec support"
> >  	default y
> > diff --git a/sound/pci/hda/Makefile b/sound/pci/hda/Makefile index
> > 24a2514..4b0a4bc 100644
> > --- a/sound/pci/hda/Makefile
> > +++ b/sound/pci/hda/Makefile
> > @@ -6,6 +6,9 @@ snd-hda-codec-$(CONFIG_PROC_FS) += hda_proc.o
> >  snd-hda-codec-$(CONFIG_SND_HDA_HWDEP) += hda_hwdep.o
> >  snd-hda-codec-$(CONFIG_SND_HDA_INPUT_BEEP) += hda_beep.o
> >
> > +# for haswell power well
> > +snd-hda-intel-$(CONFIG_SND_HDA_I915) +=	hda_i915.o
> > +
> >  # for trace-points
> >  CFLAGS_hda_codec.o := -I$(src)
> >  CFLAGS_hda_intel.o := -I$(src)
> > diff --git a/sound/pci/hda/hda_i915.c b/sound/pci/hda/hda_i915.c new
> > file mode 100644 index 0000000..76c13d5
> > --- /dev/null
> > +++ b/sound/pci/hda/hda_i915.c
> > @@ -0,0 +1,75 @@
> > +/*
> > + *  hda_i915.c - routines for Haswell HDA controller power well
> > +support
> > + *
> > + *  This program is free software; you can redistribute it and/or
> > +modify it
> > + *  under the terms of the GNU General Public License as published by
> > +the Free
> > + *  Software Foundation; either version 2 of the License, or (at your
> > +option)
> > + *  any later version.
> > + *
> > + *  This program is distributed in the hope that it will be useful,
> > +but
> > + *  WITHOUT ANY WARRANTY; without even the implied warranty of
> > +MERCHANTABILITY
> > + *  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
> > +License
> > + *  for more details.
> > + *
> > + *  You should have received a copy of the GNU General Public License
> > + *  along with this program; if not, write to the Free Software
> > +Foundation,
> > + *  Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
> > + */
> > +
> > +#include <linux/init.h>
> > +#include <linux/module.h>
> > +#include <sound/core.h>
> > +#include <drm/i915_powerwell.h>
> > +#include "hda_i915.h"
> > +
> > +static void (*get_power)(void);
> > +static void (*put_power)(void);
> > +
> > +void hda_display_power(bool enable)
> > +{
> > +	if (!get_power || !put_power)
> > +		return;
> > +
> > +	snd_printdd("HDA display power %s \n",
> > +			enable ? "Enable" : "Disable");
> > +	if (enable)
> > +		get_power();
> > +	else
> > +		put_power();
> > +}
> > +
> > +int hda_i915_init(void)
> > +{
> > +	int err = 0;
> > +
> > +	get_power = symbol_request(i915_request_power_well);
> > +	if (!get_power) {
> > +		snd_printk(KERN_WARNING "hda-i915: get_power symbol get
> fail\n");
> > +		return -ENODEV;
> > +	}
> > +
> > +	put_power = symbol_request(i915_release_power_well);
> > +	if (!put_power) {
> > +		symbol_put(i915_request_power_well);
> > +		get_power = NULL;
> > +		return -ENODEV;
> > +	}
> > +
> > +	snd_printd("HDA driver get symbol successfully from i915 module\n");
> > +
> > +	return err;
> > +}
> > +
> > +int hda_i915_exit(void)
> > +{
> > +	if (get_power) {
> > +		symbol_put(i915_request_power_well);
> > +		get_power = NULL;
> > +	}
> > +	if (put_power) {
> > +		symbol_put(i915_release_power_well);
> > +		put_power = NULL;
> > +	}
> > +
> > +	return 0;
> > +}
> > diff --git a/sound/pci/hda/hda_i915.h b/sound/pci/hda/hda_i915.h new
> > file mode 100644 index 0000000..5a63da2
> > --- /dev/null
> > +++ b/sound/pci/hda/hda_i915.h
> > @@ -0,0 +1,35 @@
> > +/*
> > + *  This program is free software; you can redistribute it and/or
> > +modify it
> > + *  under the terms of the GNU General Public License as published by
> > +the Free
> > + *  Software Foundation; either version 2 of the License, or (at your
> > +option)
> > + *  any later version.
> > + *
> > + *  This program is distributed in the hope that it will be useful,
> > +but WITHOUT
> > + *  ANY WARRANTY; without even the implied warranty of
> > +MERCHANTABILITY or
> > + *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
> > +License for
> > + *  more details.
> > + *
> > + *  You should have received a copy of the GNU General Public License
> > +along with
> > + *  this program; if not, write to the Free Software Foundation,
> > +Inc., 59
> > + *  Temple Place - Suite 330, Boston, MA  02111-1307, USA.
> > + */
> > +#ifndef __SOUND_HDA_I915_H
> > +#define __SOUND_HDA_I915_H
> > +
> > +#ifdef CONFIG_SND_HDA_I915
> > +void hda_display_power(bool enable);
> > +int hda_i915_init(void);
> > +int hda_i915_exit(void);
> > +#else
> > +static inline void hda_display_power(bool enable) {} static inline
> > +int hda_i915_init(void) {
> > +	return -ENODEV;
> > +}
> > +static inline int hda_i915_exit(void) {
> > +	return 0;
> > +}
> > +#endif
> > +
> > +#endif
> > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> > index 418bfc0..bf27693 100644
> > --- a/sound/pci/hda/hda_intel.c
> > +++ b/sound/pci/hda/hda_intel.c
> > @@ -62,6 +62,7 @@
> >  #include <linux/vga_switcheroo.h>
> >  #include <linux/firmware.h>
> >  #include "hda_codec.h"
> > +#include "hda_i915.h"
> >
> >
> >  static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; @@ -594,6 +595,7
> > @@ enum {
> >  #define AZX_DCAPS_4K_BDLE_BOUNDARY (1 << 23)	/* BDLE in 4k
> boundary */
> >  #define AZX_DCAPS_COUNT_LPIB_DELAY  (1 << 25)	/* Take LPIB as
> delay */
> >  #define AZX_DCAPS_PM_RUNTIME	(1 << 26)	/* runtime PM support */
> > +#define AZX_DCAPS_I915_POWERWELL (1 << 27)	/* HSW i915 power well
> support */
> >
> >  /* quirks for Intel PCH */
> >  #define AZX_DCAPS_INTEL_PCH_NOPM \
> > @@ -2869,6 +2871,8 @@ static int azx_suspend(struct device *dev)
> >  	pci_disable_device(pci);
> >  	pci_save_state(pci);
> >  	pci_set_power_state(pci, PCI_D3hot);
> > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL)
> > +		hda_display_power(false);
> >  	return 0;
> >  }
> >
> > @@ -2881,6 +2885,8 @@ static int azx_resume(struct device *dev)
> >  	if (chip->disabled)
> >  		return 0;
> >
> > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL)
> > +		hda_display_power(true);
> >  	pci_set_power_state(pci, PCI_D0);
> >  	pci_restore_state(pci);
> >  	if (pci_enable_device(pci) < 0) {
> > @@ -2913,6 +2919,8 @@ static int azx_runtime_suspend(struct device
> > *dev)
> >
> >  	azx_stop_chip(chip);
> >  	azx_clear_irq_pending(chip);
> > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL)
> > +		hda_display_power(false);
> >  	return 0;
> >  }
> >
> > @@ -2921,6 +2929,8 @@ static int azx_runtime_resume(struct device *dev)
> >  	struct snd_card *card = dev_get_drvdata(dev);
> >  	struct azx *chip = card->private_data;
> >
> > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL)
> > +		hda_display_power(true);
> >  	azx_init_pci(chip);
> >  	azx_init_chip(chip, 1);
> >  	return 0;
> > @@ -3144,6 +3154,10 @@ static int azx_free(struct azx *chip)
> >  	if (chip->fw)
> >  		release_firmware(chip->fw);
> >  #endif
> > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
> > +		hda_display_power(false);
> > +		hda_i915_exit();
> > +	}
> >  	kfree(chip);
> >
> >  	return 0;
> > @@ -3700,6 +3714,19 @@ static int azx_probe(struct pci_dev *pci,
> >  		chip->disabled = true;
> >  	}
> >
> > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { #ifdef
> > +CONFIG_SND_HDA_I915
> > +		err = hda_i915_init();
> > +		if (err < 0) {
> > +			snd_printk(KERN_ERR SFX "Error request power-well from
> i915\n");
> > +			goto out_free;
> > +		}
> > +		hda_display_power(true);
> > +#else
> > +		snd_printk(KERN_ERR SFX "Haswell must build in
> > +CONFIG_SND_HDA_I915\n"); #endif
> > +	}
> > +
> >  	probe_now = !chip->disabled;
> >  	if (probe_now) {
> >  		err = azx_first_init(chip);
> > @@ -3799,6 +3826,7 @@ out_free:
> >  static void azx_remove(struct pci_dev *pci)  {
> >  	struct snd_card *card = pci_get_drvdata(pci);
> > +	struct azx *chip = card->private_data;
> >
> >  	if (pci_dev_run_wake(pci))
> >  		pm_runtime_get_noresume(&pci->dev);
> > @@ -3806,6 +3834,10 @@ static void azx_remove(struct pci_dev *pci)
> >  	if (card)
> >  		snd_card_free(card);
> >  	pci_set_drvdata(pci, NULL);
> > +	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
> > +		hda_display_power(false);
> > +		hda_i915_exit();
> > +	}
> 
> As mentioned in the previous post, you can't refer to chip instance at this point.
> It's been already freed in snd_card_free().

Oh sorry I misunderstand your point, the code should be put before snd_card_free():
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index eb25888..e6a07f9 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -3837,13 +3837,14 @@ static void azx_remove(struct pci_dev *pci)
        if (pci_dev_run_wake(pci))
                pm_runtime_get_noresume(&pci->dev);

-       if (card)
-               snd_card_free(card);
-       pci_set_drvdata(pci, NULL);
        if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
                hda_display_power(false);
                hda_i915_exit();
        }
+
+       if (card)
+               snd_card_free(card);
+       pci_set_drvdata(pci, NULL);
 }

 /* PCI IDs */

But I'm thinking it can be removed totally as azx_dev_free() always do that.

Thanks
--xingchao

> 
> 
> Takashi
> 
> 
> >  }
> >
> >  /* PCI IDs */
> > @@ -3835,11 +3867,14 @@ static DEFINE_PCI_DEVICE_TABLE(azx_ids) = {
> >  	  .driver_data = AZX_DRIVER_PCH | AZX_DCAPS_INTEL_PCH },
> >  	/* Haswell */
> >  	{ PCI_DEVICE(0x8086, 0x0a0c),
> > -	  .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH },
> > +	  .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH |
> > +	  AZX_DCAPS_I915_POWERWELL },
> >  	{ PCI_DEVICE(0x8086, 0x0c0c),
> > -	  .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH },
> > +	  .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH |
> > +	  AZX_DCAPS_I915_POWERWELL },
> >  	{ PCI_DEVICE(0x8086, 0x0d0c),
> > -	  .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH },
> > +	  .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH |
> > +	  AZX_DCAPS_I915_POWERWELL },
> >  	/* 5 Series/3400 */
> >  	{ PCI_DEVICE(0x8086, 0x3b56),
> >  	  .driver_data = AZX_DRIVER_SCH | AZX_DCAPS_INTEL_PCH_NOPM },
> > --
> > 1.7.9.5
> >