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linux-next/sound/hda/ext/hdac_ext_bus.c
Kai Vehmanen 163cd1059a
ASoC: hdac: make SOF HDA codec driver probe deterministic
To provide backward compatibility to older systems, the SOF HDA driver
allows user to specify which HDMI codec driver to use at runtime via
kernel parameter. This mechanism has a subtle flaw in that it assumes
the codec drivers not to be loaded when the SOF PCI driver is loaded.

The problem is rooted in use of the hdev->type field.
snd_hdac_ext_bus_device_init() initializes this field to HDA_DEV_ASOC.
This signals the HDA core that ASoC drivers should be considered in
driver matching (hda_bus_match()). The SOF and SST drivers continue by
overriding this field to HDA_DEV_LEGACY and proceeding to load driver
modules with request_module(). Correct drivers will get loaded and
attached.

If however the codec drivers are already loaded when
snd_hdac_ext_bus_device_init() is called, the matching will not work as
expected as device type is still set to HDA_DEV_ASOC. Specifically if
hdac-hdmi is attached when machine driver is configured to use hdac-hda,
this leads to out-of-bounds memory access in
hda_dsp_hdmi_build_controls().

Fix the issue by adding codec type as a parameter to
snd_hdac_ext_bus_device_init() and ensuring type is set correctly from
the start.

Fixes: 139c7febad ("ASoC: SOF: Intel: add support for snd-hda-codec-hdmi")
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200921100841.2882662-1-kai.vehmanen@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-09-21 23:57:24 +01:00

196 lines
4.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* hdac-ext-bus.c - HD-audio extended core bus functions.
*
* Copyright (C) 2014-2015 Intel Corp
* Author: Jeeja KP <jeeja.kp@intel.com>
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <sound/hdaudio_ext.h>
MODULE_DESCRIPTION("HDA extended core");
MODULE_LICENSE("GPL v2");
/**
* snd_hdac_ext_bus_init - initialize a HD-audio extended bus
* @bus: the pointer to HDAC bus object
* @dev: device pointer
* @ops: bus verb operators
* @ext_ops: operators used for ASoC HDA codec drivers
*
* Returns 0 if successful, or a negative error code.
*/
int snd_hdac_ext_bus_init(struct hdac_bus *bus, struct device *dev,
const struct hdac_bus_ops *ops,
const struct hdac_ext_bus_ops *ext_ops)
{
int ret;
ret = snd_hdac_bus_init(bus, dev, ops);
if (ret < 0)
return ret;
bus->ext_ops = ext_ops;
/* FIXME:
* Currently only one bus is supported, if there is device with more
* buses, bus->idx should be greater than 0, but there needs to be a
* reliable way to always assign same number.
*/
bus->idx = 0;
bus->cmd_dma_state = true;
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_init);
/**
* snd_hdac_ext_bus_exit - clean up a HD-audio extended bus
* @bus: the pointer to HDAC bus object
*/
void snd_hdac_ext_bus_exit(struct hdac_bus *bus)
{
snd_hdac_bus_exit(bus);
WARN_ON(!list_empty(&bus->hlink_list));
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_exit);
static void default_release(struct device *dev)
{
snd_hdac_ext_bus_device_exit(dev_to_hdac_dev(dev));
}
/**
* snd_hdac_ext_bus_device_init - initialize the HDA extended codec base device
* @bus: hdac bus to attach to
* @addr: codec address
* @hdev: hdac device to init
* @type: codec type (HDAC_DEV_*) to use for this device
*
* Returns zero for success or a negative error code.
*/
int snd_hdac_ext_bus_device_init(struct hdac_bus *bus, int addr,
struct hdac_device *hdev, int type)
{
char name[15];
int ret;
hdev->bus = bus;
snprintf(name, sizeof(name), "ehdaudio%dD%d", bus->idx, addr);
ret = snd_hdac_device_init(hdev, bus, name, addr);
if (ret < 0) {
dev_err(bus->dev, "device init failed for hdac device\n");
return ret;
}
hdev->type = type;
hdev->dev.release = default_release;
ret = snd_hdac_device_register(hdev);
if (ret) {
dev_err(bus->dev, "failed to register hdac device\n");
snd_hdac_ext_bus_device_exit(hdev);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_device_init);
/**
* snd_hdac_ext_bus_device_exit - clean up a HD-audio extended codec base device
* @hdev: hdac device to clean up
*/
void snd_hdac_ext_bus_device_exit(struct hdac_device *hdev)
{
snd_hdac_device_exit(hdev);
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_device_exit);
/**
* snd_hdac_ext_bus_device_remove - remove HD-audio extended codec base devices
*
* @bus: the pointer to HDAC bus object
*/
void snd_hdac_ext_bus_device_remove(struct hdac_bus *bus)
{
struct hdac_device *codec, *__codec;
/*
* we need to remove all the codec devices objects created in the
* snd_hdac_ext_bus_device_init
*/
list_for_each_entry_safe(codec, __codec, &bus->codec_list, list) {
snd_hdac_device_unregister(codec);
put_device(&codec->dev);
}
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_device_remove);
#define dev_to_hdac(dev) (container_of((dev), \
struct hdac_device, dev))
static inline struct hdac_driver *get_hdrv(struct device *dev)
{
struct hdac_driver *hdrv = drv_to_hdac_driver(dev->driver);
return hdrv;
}
static inline struct hdac_device *get_hdev(struct device *dev)
{
struct hdac_device *hdev = dev_to_hdac_dev(dev);
return hdev;
}
static int hda_ext_drv_probe(struct device *dev)
{
return (get_hdrv(dev))->probe(get_hdev(dev));
}
static int hdac_ext_drv_remove(struct device *dev)
{
return (get_hdrv(dev))->remove(get_hdev(dev));
}
static void hdac_ext_drv_shutdown(struct device *dev)
{
return (get_hdrv(dev))->shutdown(get_hdev(dev));
}
/**
* snd_hda_ext_driver_register - register a driver for ext hda devices
*
* @drv: ext hda driver structure
*/
int snd_hda_ext_driver_register(struct hdac_driver *drv)
{
drv->type = HDA_DEV_ASOC;
drv->driver.bus = &snd_hda_bus_type;
/* we use default match */
if (drv->probe)
drv->driver.probe = hda_ext_drv_probe;
if (drv->remove)
drv->driver.remove = hdac_ext_drv_remove;
if (drv->shutdown)
drv->driver.shutdown = hdac_ext_drv_shutdown;
return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(snd_hda_ext_driver_register);
/**
* snd_hda_ext_driver_unregister - unregister a driver for ext hda devices
*
* @drv: ext hda driver structure
*/
void snd_hda_ext_driver_unregister(struct hdac_driver *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(snd_hda_ext_driver_unregister);