linux_dsm_epyc7002/sound/hda/hdac_component.c
Takashi Iwai 4bdc42094d ALSA: hda: Fix racy display power access
snd_hdac_display_power() doesn't handle the concurrent calls carefully
enough, and it may lead to the doubly get_power or put_power calls,
when a runtime PM and an async work get called in racy way.

This patch addresses it by reusing the bus->lock mutex that has been
used for protecting the link state change in ext bus code, so that it
can protect against racy display state changes.  The initialization of
bus->lock was moved from snd_hdac_ext_bus_init() to
snd_hdac_bus_init() as well accordingly.

Testcase: igt/i915_pm_rpm/module-reload #glk-dsi
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/s5h8swiunph.wl-tiwai@suse.de
2019-04-10 14:13:47 +01:00

351 lines
9.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
// hdac_component.c - routines for sync between HD-A core and DRM driver
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/component.h>
#include <sound/core.h>
#include <sound/hdaudio.h>
#include <sound/hda_component.h>
#include <sound/hda_register.h>
static void hdac_acomp_release(struct device *dev, void *res)
{
}
static struct drm_audio_component *hdac_get_acomp(struct device *dev)
{
return devres_find(dev, hdac_acomp_release, NULL, NULL);
}
/**
* snd_hdac_set_codec_wakeup - Enable / disable HDMI/DP codec wakeup
* @bus: HDA core bus
* @enable: enable or disable the wakeup
*
* This function is supposed to be used only by a HD-audio controller
* driver that needs the interaction with graphics driver.
*
* This function should be called during the chip reset, also called at
* resume for updating STATESTS register read.
*
* Returns zero for success or a negative error code.
*/
int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable)
{
struct drm_audio_component *acomp = bus->audio_component;
if (!acomp || !acomp->ops)
return -ENODEV;
if (!acomp->ops->codec_wake_override)
return 0;
dev_dbg(bus->dev, "%s codec wakeup\n",
enable ? "enable" : "disable");
acomp->ops->codec_wake_override(acomp->dev, enable);
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_set_codec_wakeup);
/**
* snd_hdac_display_power - Power up / down the power refcount
* @bus: HDA core bus
* @idx: HDA codec address, pass HDA_CODEC_IDX_CONTROLLER for controller
* @enable: power up or down
*
* This function is used by either HD-audio controller or codec driver that
* needs the interaction with graphics driver.
*
* This function updates the power status, and calls the get_power() and
* put_power() ops accordingly, toggling the codec wakeup, too.
*/
void snd_hdac_display_power(struct hdac_bus *bus, unsigned int idx, bool enable)
{
struct drm_audio_component *acomp = bus->audio_component;
dev_dbg(bus->dev, "display power %s\n",
enable ? "enable" : "disable");
mutex_lock(&bus->lock);
if (enable)
set_bit(idx, &bus->display_power_status);
else
clear_bit(idx, &bus->display_power_status);
if (!acomp || !acomp->ops)
goto unlock;
if (bus->display_power_status) {
if (!bus->display_power_active) {
unsigned long cookie = -1;
if (acomp->ops->get_power)
cookie = acomp->ops->get_power(acomp->dev);
snd_hdac_set_codec_wakeup(bus, true);
snd_hdac_set_codec_wakeup(bus, false);
bus->display_power_active = cookie;
}
} else {
if (bus->display_power_active) {
unsigned long cookie = bus->display_power_active;
if (acomp->ops->put_power)
acomp->ops->put_power(acomp->dev, cookie);
bus->display_power_active = 0;
}
}
unlock:
mutex_unlock(&bus->lock);
}
EXPORT_SYMBOL_GPL(snd_hdac_display_power);
/**
* snd_hdac_sync_audio_rate - Set N/CTS based on the sample rate
* @codec: HDA codec
* @nid: the pin widget NID
* @dev_id: device identifier
* @rate: the sample rate to set
*
* This function is supposed to be used only by a HD-audio controller
* driver that needs the interaction with graphics driver.
*
* This function sets N/CTS value based on the given sample rate.
* Returns zero for success, or a negative error code.
*/
int snd_hdac_sync_audio_rate(struct hdac_device *codec, hda_nid_t nid,
int dev_id, int rate)
{
struct hdac_bus *bus = codec->bus;
struct drm_audio_component *acomp = bus->audio_component;
int port, pipe;
if (!acomp || !acomp->ops || !acomp->ops->sync_audio_rate)
return -ENODEV;
port = nid;
if (acomp->audio_ops && acomp->audio_ops->pin2port) {
port = acomp->audio_ops->pin2port(codec, nid);
if (port < 0)
return -EINVAL;
}
pipe = dev_id;
return acomp->ops->sync_audio_rate(acomp->dev, port, pipe, rate);
}
EXPORT_SYMBOL_GPL(snd_hdac_sync_audio_rate);
/**
* snd_hdac_acomp_get_eld - Get the audio state and ELD via component
* @codec: HDA codec
* @nid: the pin widget NID
* @dev_id: device identifier
* @audio_enabled: the pointer to store the current audio state
* @buffer: the buffer pointer to store ELD bytes
* @max_bytes: the max bytes to be stored on @buffer
*
* This function is supposed to be used only by a HD-audio controller
* driver that needs the interaction with graphics driver.
*
* This function queries the current state of the audio on the given
* digital port and fetches the ELD bytes onto the given buffer.
* It returns the number of bytes for the total ELD data, zero for
* invalid ELD, or a negative error code.
*
* The return size is the total bytes required for the whole ELD bytes,
* thus it may be over @max_bytes. If it's over @max_bytes, it implies
* that only a part of ELD bytes have been fetched.
*/
int snd_hdac_acomp_get_eld(struct hdac_device *codec, hda_nid_t nid, int dev_id,
bool *audio_enabled, char *buffer, int max_bytes)
{
struct hdac_bus *bus = codec->bus;
struct drm_audio_component *acomp = bus->audio_component;
int port, pipe;
if (!acomp || !acomp->ops || !acomp->ops->get_eld)
return -ENODEV;
port = nid;
if (acomp->audio_ops && acomp->audio_ops->pin2port) {
port = acomp->audio_ops->pin2port(codec, nid);
if (port < 0)
return -EINVAL;
}
pipe = dev_id;
return acomp->ops->get_eld(acomp->dev, port, pipe, audio_enabled,
buffer, max_bytes);
}
EXPORT_SYMBOL_GPL(snd_hdac_acomp_get_eld);
static int hdac_component_master_bind(struct device *dev)
{
struct drm_audio_component *acomp = hdac_get_acomp(dev);
int ret;
if (WARN_ON(!acomp))
return -EINVAL;
ret = component_bind_all(dev, acomp);
if (ret < 0)
return ret;
if (WARN_ON(!(acomp->dev && acomp->ops))) {
ret = -EINVAL;
goto out_unbind;
}
/* pin the module to avoid dynamic unbinding, but only if given */
if (!try_module_get(acomp->ops->owner)) {
ret = -ENODEV;
goto out_unbind;
}
if (acomp->audio_ops && acomp->audio_ops->master_bind) {
ret = acomp->audio_ops->master_bind(dev, acomp);
if (ret < 0)
goto module_put;
}
return 0;
module_put:
module_put(acomp->ops->owner);
out_unbind:
component_unbind_all(dev, acomp);
return ret;
}
static void hdac_component_master_unbind(struct device *dev)
{
struct drm_audio_component *acomp = hdac_get_acomp(dev);
if (acomp->audio_ops && acomp->audio_ops->master_unbind)
acomp->audio_ops->master_unbind(dev, acomp);
module_put(acomp->ops->owner);
component_unbind_all(dev, acomp);
WARN_ON(acomp->ops || acomp->dev);
}
static const struct component_master_ops hdac_component_master_ops = {
.bind = hdac_component_master_bind,
.unbind = hdac_component_master_unbind,
};
/**
* snd_hdac_acomp_register_notifier - Register audio component ops
* @bus: HDA core bus
* @aops: audio component ops
*
* This function is supposed to be used only by a HD-audio controller
* driver that needs the interaction with graphics driver.
*
* This function sets the given ops to be called by the graphics driver.
*
* Returns zero for success or a negative error code.
*/
int snd_hdac_acomp_register_notifier(struct hdac_bus *bus,
const struct drm_audio_component_audio_ops *aops)
{
if (!bus->audio_component)
return -ENODEV;
bus->audio_component->audio_ops = aops;
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_acomp_register_notifier);
/**
* snd_hdac_acomp_init - Initialize audio component
* @bus: HDA core bus
* @match_master: match function for finding components
* @extra_size: Extra bytes to allocate
*
* This function is supposed to be used only by a HD-audio controller
* driver that needs the interaction with graphics driver.
*
* This function initializes and sets up the audio component to communicate
* with graphics driver.
*
* Unlike snd_hdac_i915_init(), this function doesn't synchronize with the
* binding with the DRM component. Each caller needs to sync via master_bind
* audio_ops.
*
* Returns zero for success or a negative error code.
*/
int snd_hdac_acomp_init(struct hdac_bus *bus,
const struct drm_audio_component_audio_ops *aops,
int (*match_master)(struct device *, int, void *),
size_t extra_size)
{
struct component_match *match = NULL;
struct device *dev = bus->dev;
struct drm_audio_component *acomp;
int ret;
if (WARN_ON(hdac_get_acomp(dev)))
return -EBUSY;
acomp = devres_alloc(hdac_acomp_release, sizeof(*acomp) + extra_size,
GFP_KERNEL);
if (!acomp)
return -ENOMEM;
acomp->audio_ops = aops;
bus->audio_component = acomp;
devres_add(dev, acomp);
component_match_add_typed(dev, &match, match_master, bus);
ret = component_master_add_with_match(dev, &hdac_component_master_ops,
match);
if (ret < 0)
goto out_err;
return 0;
out_err:
bus->audio_component = NULL;
devres_destroy(dev, hdac_acomp_release, NULL, NULL);
dev_info(dev, "failed to add audio component master (%d)\n", ret);
return ret;
}
EXPORT_SYMBOL_GPL(snd_hdac_acomp_init);
/**
* snd_hdac_acomp_exit - Finalize audio component
* @bus: HDA core bus
*
* This function is supposed to be used only by a HD-audio controller
* driver that needs the interaction with graphics driver.
*
* This function releases the audio component that has been used.
*
* Returns zero for success or a negative error code.
*/
int snd_hdac_acomp_exit(struct hdac_bus *bus)
{
struct device *dev = bus->dev;
struct drm_audio_component *acomp = bus->audio_component;
if (!acomp)
return 0;
if (WARN_ON(bus->display_power_active) && acomp->ops)
acomp->ops->put_power(acomp->dev, bus->display_power_active);
bus->display_power_active = 0;
bus->display_power_status = 0;
component_master_del(dev, &hdac_component_master_ops);
bus->audio_component = NULL;
devres_destroy(dev, hdac_acomp_release, NULL, NULL);
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_acomp_exit);