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

At Tue, 14 May 2013 19:44:19 +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 | 8 ++++ sound/pci/hda/Makefile | 3 ++ sound/pci/hda/hda_i915.c | 92 +++++++++++++++++++++++++++++++++++++++++++++ sound/pci/hda/hda_i915.h | 35 +++++++++++++++++ sound/pci/hda/hda_intel.c | 33 ++++++++++++++-- 5 files changed, 168 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..d9e71e4 100644 --- a/sound/pci/hda/Kconfig +++ b/sound/pci/hda/Kconfig @@ -152,6 +152,14 @@ 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
• default y
• help

•  Say Y here to include full HDMI and DisplayPort HD-audio controller/codec
  

•  support for Intel Haswell graphics cards based on the i915 driver.
  

Do we need to make this selectable? If you have i915 driver, this can be always set.

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..96ca9e7 --- /dev/null +++ b/sound/pci/hda/hda_i915.c @@ -0,0 +1,92 @@ +/*

• • 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 const char *module_name = "i915"; +static struct module *i915; +static void (*get_power)(void); +static void (*put_power)(void);

+void hda_display_power(bool enable) +{

• if (!get_power || !put_power)

• return;
  

• snd_printk(KERN_DEBUG "HDA display power %s \n",

• 	enable ? "Enable" : "Disable");
  

Use snd_printdd() for such a frequent debug message. We don't want to see this message at each time you open/close the audio stream.

• if (enable)

• get_power();
  

• else

• put_power();
  

+}

+/* in case i915 not loaded, try load i915 first */ +static int load_i915(void) +{

• int err;
• mutex_lock(&module_mutex);
• i915 = find_module(module_name);
• mutex_unlock(&module_mutex);
• if (!i915) {

• err = request_module(module_name);
  

• if (err < 0)
  

• 	return -ENODEV;
  

Why not passing the returned error code?

Also, you need to get i915 module again after the successful request_module(). request_module() doesn't give the module reference.

Also, we can skip the whole load_i915() if i915 driver is built-in, i.e.

#ifdef CONFIG_DRM_i915_MODULE static int load_i915(void) { .... } #else #define load_i915(void) (-ENODEV) #endif

• }
• return 0;

+}

+int hda_i915_init(void) +{

• get_power = symbol_get(i915_request_power_well);
• if (!get_power) {

• snd_printk(KERN_WARNING "hda-i915: get symbol fail, try again!\n");
  

Doesn't make sense to give a warning at this point. The fact that no symbol is taken at this point is no real error. The error should be reported when the module load failed or the symbol_get() failed twice.

• if (load_i915() < 0)
  

• 	return -ENODEV;
  

• get_power = symbol_get(i915_request_power_well);
  

• if (!get_power)
  

• 	return -ENODEV;
  

The i915 module should be unreferenced in the error path.

• }
• put_power = symbol_get(i915_release_power_well);
• if (!put_power)

• return -ENODEV;
  

Ditto.

• snd_printk(KERN_INFO "HDA driver get symbol successfully from i915 module\n");

Use snd_printd() as a debug message, if any.

• return 0;

+}

+int hda_i915_exit(void) +{

• if (get_power)

• symbol_put(i915_request_power_well);
  

• if (put_power)

• symbol_put(i915_release_power_well);
  

i915 module should be unreferenced at exit, too.

• return 0;

+} diff --git a/sound/pci/hda/hda_i915.h b/sound/pci/hda/hda_i915.h new file mode 100644 index 0000000..cad4971 --- /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 0;

+} +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..6854a7e 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;

@@ -3700,6 +3710,15 @@ static int azx_probe(struct pci_dev *pci, chip->disabled = true; }

• if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {

• err = hda_i915_init();
  

• if (err < 0) {
  

• 	snd_printk(KERN_ERR "Error request power-well from i915\n");
  

• 	goto out_free;
  

• }
  

• hda_display_power(true);
  

• }
• probe_now = !chip->disabled; if (probe_now) { err = azx_first_init(chip);

Missing hda_display_power(false) and hda_i915_exit() in the error path.

@@ -3799,6 +3818,7 @@ 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 +3826,10 @@ 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();
  

• }

}

/* PCI IDs */ @@ -3835,11 +3859,14 @@ 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},
  

Try to follow the indentation / spacing of the original code.

thanks,

Takashi