forked from Minki/linux
9e4d59ada4
This is a fix for Linux 4.10-rc1.
In C language specification, a bit-field is interpreted as a signed or
unsigned integer type consisting of the specified number of bits.
In GCC manual, the range of a signed bit field of N bits is from
-(2^N) / 2 to ((2^N) / 2) - 1
https://www.gnu.org/software/gnu-c-manual/gnu-c-manual.html#Bit-Fields
Therefore, when defined as 1 bit-field with signed type, variables can
represents -1 and 0.
The snd-soc-hdmi-codec module includes a structure which has signed type
members with bit-fields. Codes of this module assign 0 and 1 to the
members. This seems to result in implementation-dependent behaviours.
As of v4.10-rc1 merge window, outside of sound subsystem, this structure
is referred by below GPU modules.
- tda998x
- sti-drm
- mediatek-drm-hdmi
- msm
As long as I review their codes relevant to the structure, the structure
members are used just for condition statements and printk formats.
My proposal of change is a bit intrusive to the printk formats but this
may be acceptable.
Totally, it's reasonable to use unsigned type for the structure members.
This bug is detected by Sparse, static code analyzer with below warnings.
./include/sound/hdmi-codec.h:39:26: error: dubious one-bit signed bitfield
./include/sound/hdmi-codec.h:40:28: error: dubious one-bit signed bitfield
./include/sound/hdmi-codec.h:41:29: error: dubious one-bit signed bitfield
./include/sound/hdmi-codec.h:42:31: error: dubious one-bit signed bitfield
Fixes: 09184118a8 ("ASoC: hdmi-codec: Add hdmi-codec for external HDMI-encoders")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
CC: stable@vger.kernel.org
104 lines
2.2 KiB
C
104 lines
2.2 KiB
C
/*
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* hdmi-codec.h - HDMI Codec driver API
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*
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* Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com
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*
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* Author: Jyri Sarha <jsarha@ti.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#ifndef __HDMI_CODEC_H__
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#define __HDMI_CODEC_H__
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#include <linux/hdmi.h>
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#include <drm/drm_edid.h>
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#include <sound/asoundef.h>
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#include <uapi/sound/asound.h>
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/*
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* Protocol between ASoC cpu-dai and HDMI-encoder
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*/
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struct hdmi_codec_daifmt {
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enum {
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HDMI_I2S,
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HDMI_RIGHT_J,
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HDMI_LEFT_J,
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HDMI_DSP_A,
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HDMI_DSP_B,
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HDMI_AC97,
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HDMI_SPDIF,
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} fmt;
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unsigned int bit_clk_inv:1;
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unsigned int frame_clk_inv:1;
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unsigned int bit_clk_master:1;
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unsigned int frame_clk_master:1;
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};
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/*
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* HDMI audio parameters
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*/
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struct hdmi_codec_params {
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struct hdmi_audio_infoframe cea;
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struct snd_aes_iec958 iec;
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int sample_rate;
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int sample_width;
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int channels;
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};
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struct hdmi_codec_pdata;
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struct hdmi_codec_ops {
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/*
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* Called when ASoC starts an audio stream setup.
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* Optional
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*/
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int (*audio_startup)(struct device *dev, void *data);
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/*
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* Configures HDMI-encoder for audio stream.
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* Mandatory
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*/
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int (*hw_params)(struct device *dev, void *data,
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struct hdmi_codec_daifmt *fmt,
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struct hdmi_codec_params *hparms);
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/*
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* Shuts down the audio stream.
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* Mandatory
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*/
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void (*audio_shutdown)(struct device *dev, void *data);
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/*
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* Mute/unmute HDMI audio stream.
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* Optional
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*/
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int (*digital_mute)(struct device *dev, void *data, bool enable);
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/*
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* Provides EDID-Like-Data from connected HDMI device.
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* Optional
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*/
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int (*get_eld)(struct device *dev, void *data,
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uint8_t *buf, size_t len);
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};
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/* HDMI codec initalization data */
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struct hdmi_codec_pdata {
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const struct hdmi_codec_ops *ops;
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uint i2s:1;
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uint spdif:1;
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int max_i2s_channels;
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void *data;
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};
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#define HDMI_CODEC_DRV_NAME "hdmi-audio-codec"
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#endif /* __HDMI_CODEC_H__ */
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