Re: [PATCH 2/5] ALSA: hda - Add external module hda-i915 for power well

[Takashi Iwai <tiwai@suse.de>]

At Mon, 13 May 2013 15:37:25 +0800,
Wang Xingchao wrote:
> 
> This new added external module hda_i915 only built in when
> gfx i915 module built in. It includes hda_display_power()
> api implementation for hda controller driver, which will
> ask gfx driver for reqeust/release power well on Intel Haswell.

As David suggested, there is no merit to split a module just for
this.  If this was intended for solving the module dependency, this
should be resolved via dynamic symbol lookup.


Takashi

> 
> Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
> ---
>  sound/pci/hda/Kconfig    |   13 +++++++++++++
>  sound/pci/hda/Makefile   |    6 ++++++
>  sound/pci/hda/hda_i915.c |   37 +++++++++++++++++++++++++++++++++++++
>  sound/pci/hda/hda_i915.h |   10 ++++++++++
>  4 files changed, 66 insertions(+)
>  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..8347325 100644
> --- a/sound/pci/hda/Kconfig
> +++ b/sound/pci/hda/Kconfig
> @@ -152,6 +152,19 @@ 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.
> +
> +	  When the HD-audio driver is built as a module, the controller/codec
> +	  support code is also built as another module,
> +	  snd-hda-i915.
> +	  This module is automatically loaded at probing.
> +
>  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..00768dd 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-$(CONFIG_SND_HDA_INPUT_BEEP) += hda_beep.o
>  
> +# for haswell power well
> +snd-hda-i915-objs :=	hda_i915.o
> +
>  # for trace-points
>  CFLAGS_hda_codec.o := -I$(src)
>  CFLAGS_hda_intel.o := -I$(src)
> @@ -59,6 +62,9 @@ endif
>  ifdef CONFIG_SND_HDA_CODEC_HDMI
>  obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-hdmi.o
>  endif
> +ifdef CONFIG_SND_HDA_I915
> +obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-i915.o
> +endif
>  
>  # this must be the last entry after codec drivers;
>  # otherwise the codec patches won't be hooked before the PCI probe
> diff --git a/sound/pci/hda/hda_i915.c b/sound/pci/hda/hda_i915.c
> new file mode 100644
> index 0000000..7e8ddaa
> --- /dev/null
> +++ b/sound/pci/hda/hda_i915.c
> @@ -0,0 +1,37 @@
> +/*
> + *  patch_hdmi_i915.c - routines for Haswell HDMI/DisplayPort power well
> + *
> + *  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"
> +
> +/* Power well has impact on Haswell controller and codecs */
> +void hda_display_power(bool enable)
> +{
> +	snd_printk(KERN_INFO "HDA display power %d \n", enable);
> +	if (enable)
> +		i915_request_power_well("hda");
> +	else
> +		i915_release_power_well("hda");
> +}
> +EXPORT_SYMBOL(hda_display_power);
> +
> +MODULE_DESCRIPTION("HDA power well");
> +MODULE_LICENSE("GPL");
> diff --git a/sound/pci/hda/hda_i915.h b/sound/pci/hda/hda_i915.h
> new file mode 100644
> index 0000000..a7e5324
> --- /dev/null
> +++ b/sound/pci/hda/hda_i915.h
> @@ -0,0 +1,10 @@
> +#ifndef __SOUND_HDA_I915_H
> +#define __SOUND_HDA_I915_H
> +
> +#ifdef CONFIG_SND_HDA_I915
> +void hda_display_power(bool enable);
> +#else
> +void hda_display_power(bool enable) {}
> +#endif
> +
> +#endif
> -- 
> 1.7.9.5
> 
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