staging: bcm2835-audio: Disconnect and free vchi_instance on module_exit()

In the current implementation, vchi_instance is inited during the first
call of bcm2835_audio_open_connection(), and is never freed. It causes a
memory leak when the module `snd_bcm2835` is removed.

Here is how this commit fixes it:

* the VCHI context (including vchi_instance) is created once in the
  platform's devres
* the VCHI context is allocated and connected once during module_init()
* all created bcm2835_chips have a pointer to this VCHI context
* bcm2835_audio_open_connection() can access the VCHI context through the
  associated bcm2835_chip
* the VCHI context is disconnected and freed once during module_exit()

After this commit is applied, I don't see other issues with the module's
init/exit, so I also remove the associated TODO task.

Steps to reproduce the memory leak before this commit:

~~~~
root@raspberrypi:/home/pi# aplay test0.wav
Playing WAVE 'test0.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Ster
^CAborted by signal Interrupt...
root@raspberrypi:/home/pi# rmmod snd_bcm2835
root@raspberrypi:/home/pi# modprobe snd_bcm2835
root@raspberrypi:/home/pi# aplay test0.wav
Playing WAVE 'test0.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Ster
^CAborted by signal Interrupt...
root@raspberrypi:/home/pi# echo scan > /sys/kernel/debug/kmemleak
root@raspberrypi:/home/pi# cat /sys/kernel/debug/kmemleak
unreferenced object 0xb6794c00 (size 128):
  comm "aplay", pid 406, jiffies 36870 (age 116.650s)
  hex dump (first 32 bytes):
    08 a5 82 81 01 00 00 00 08 4c 79 b6 08 4c 79 b6  .........Ly..Ly.
    00 00 00 00 00 00 00 00 ad 4e ad de ff ff ff ff  .........N......
  backtrace:
    [<802af5e0>] kmem_cache_alloc_trace+0x294/0x3d0
    [<806ce620>] vchiq_initialise+0x98/0x1b0
    [<806d0b34>] vchi_initialise+0x24/0x34
    [<7f1311ec>] 0x7f1311ec
    [<7f1303bc>] 0x7f1303bc
    [<7f130590>] 0x7f130590
    [<7f111fd8>] snd_pcm_open_substream+0x68/0xc4 [snd_pcm]
    [<7f112108>] snd_pcm_open+0xd4/0x248 [snd_pcm]
    [<7f112334>] snd_pcm_playback_open+0x4c/0x6c [snd_pcm]
    [<7f0e250c>] snd_open+0xa8/0x14c [snd]
    [<802ce590>] chrdev_open+0xac/0x188
    [<802c57b4>] do_dentry_open+0x10c/0x314
    [<802c6ba8>] vfs_open+0x5c/0x88
    [<802d9a68>] path_openat+0x368/0x944
    [<802dacd4>] do_filp_open+0x70/0xc4
    [<802c6f70>] do_sys_open+0x110/0x1d4
~~~~

Signed-off-by: Kirill Marinushkin <k.marinushkin@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: devel@driverdev.osuosl.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index a4a48f31f1a33c71944bf19f311565509441e4c6..f0cefa1b7b0f5b53caa747b50ea072acbfc463ac 100644 (file)
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -22,7 +22,6 @@
 
 /* ---- Include Files -------------------------------------------------------- */
 
-#include "interface/vchi/vchi.h"
 #include "vc_vchi_audioserv_defs.h"
 
 /* ---- Private Constants and Types ------------------------------------------ */
@@ -360,14 +359,46 @@ static int vc_vchi_audio_deinit(struct bcm2835_audio_instance *instance)
        return 0;
 }
 
+int bcm2835_new_vchi_ctx(struct bcm2835_vchi_ctx *vchi_ctx)
+{
+       int ret;
+
+       /* Initialize and create a VCHI connection */
+       ret = vchi_initialise(&vchi_ctx->vchi_instance);
+       if (ret) {
+               LOG_ERR("%s: failed to initialise VCHI instance (ret=%d)\n",
+                       __func__, ret);
+
+               return -EIO;
+       }
+
+       ret = vchi_connect(NULL, 0, vchi_ctx->vchi_instance);
+       if (ret) {
+               LOG_ERR("%s: failed to connect VCHI instance (ret=%d)\n",
+                       __func__, ret);
+
+               kfree(vchi_ctx->vchi_instance);
+               vchi_ctx->vchi_instance = NULL;
+
+               return -EIO;
+       }
+
+       return 0;
+}
+
+void bcm2835_free_vchi_ctx(struct bcm2835_vchi_ctx *vchi_ctx)
+{
+       /* Close the VCHI connection - it will also free vchi_instance */
+       WARN_ON(vchi_disconnect(vchi_ctx->vchi_instance));
+
+       vchi_ctx->vchi_instance = NULL;
+}
+
 static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream)
 {
-       static VCHI_INSTANCE_T vchi_instance;
-       static VCHI_CONNECTION_T *vchi_connection;
-       static int initted;
        struct bcm2835_audio_instance *instance =
                (struct bcm2835_audio_instance *)alsa_stream->instance;
-       int ret;
+       struct bcm2835_vchi_ctx *vhci_ctx = alsa_stream->chip->vchi_ctx;
 
        LOG_INFO("%s: start\n", __func__);
        BUG_ON(instance);
@@ -379,28 +410,9 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
                return 0;
        }
 
-       /* Initialize and create a VCHI connection */
-       if (!initted) {
-               ret = vchi_initialise(&vchi_instance);
-               if (ret) {
-                       LOG_ERR("%s: failed to initialise VCHI instance (ret=%d)\n",
-                               __func__, ret);
-
-                       return -EIO;
-               }
-               ret = vchi_connect(NULL, 0, vchi_instance);
-               if (ret) {
-                       LOG_ERR("%s: failed to connect VCHI instance (ret=%d)\n",
-                               __func__, ret);
-
-                       kfree(vchi_instance);
-                       return -EIO;
-               }
-               initted = 1;
-       }
-
        /* Initialize an instance of the audio service */
-       instance = vc_vchi_audio_init(vchi_instance, &vchi_connection, 1);
+       instance = vc_vchi_audio_init(vhci_ctx->vchi_instance,
+                                     &vhci_ctx->vchi_connection, 1);
 
        if (IS_ERR(instance)) {
                LOG_ERR("%s: failed to initialize audio service\n", __func__);

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
index 0ed21dd08170eb3c2c4697d01cb37b58b4af6325..da0fa34501faddaeca0039aa73897d2b0dd08f9f 100644 (file)
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c
@@ -54,6 +54,36 @@ static int snd_devm_add_child(struct device *dev, struct device *child)
        return 0;
 }
 
+static void bcm2835_devm_free_vchi_ctx(struct device *dev, void *res)
+{
+       struct bcm2835_vchi_ctx *vchi_ctx = res;
+
+       bcm2835_free_vchi_ctx(vchi_ctx);
+}
+
+static int bcm2835_devm_add_vchi_ctx(struct device *dev)
+{
+       struct bcm2835_vchi_ctx *vchi_ctx;
+       int ret;
+
+       vchi_ctx = devres_alloc(bcm2835_devm_free_vchi_ctx, sizeof(*vchi_ctx),
+                               GFP_KERNEL);
+       if (!vchi_ctx)
+               return -ENOMEM;
+
+       memset(vchi_ctx, 0, sizeof(*vchi_ctx));
+
+       ret = bcm2835_new_vchi_ctx(vchi_ctx);
+       if (ret) {
+               devres_free(vchi_ctx);
+               return ret;
+       }
+
+       devres_add(dev, vchi_ctx);
+
+       return 0;
+}
+
 static void snd_bcm2835_release(struct device *dev)
 {
        struct bcm2835_chip *chip = dev_get_drvdata(dev);
@@ -95,8 +125,6 @@ static int snd_bcm2835_dev_free(struct snd_device *device)
        struct bcm2835_chip *chip = device->device_data;
        struct snd_card *card = chip->card;
 
-       /* TODO: free pcm, ctl */
-
        snd_device_free(card, chip);
 
        return 0;
@@ -122,6 +150,13 @@ static int snd_bcm2835_create(struct snd_card *card,
 
        chip->card = card;
 
+       chip->vchi_ctx = devres_find(card->dev->parent,
+                                    bcm2835_devm_free_vchi_ctx, NULL, NULL);
+       if (!chip->vchi_ctx) {
+               kfree(chip);
+               return -ENODEV;
+       }
+
        err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
        if (err) {
                kfree(chip);
@@ -392,6 +427,10 @@ static int snd_bcm2835_alsa_probe_dt(struct platform_device *pdev)
                         numchans);
        }
 
+       err = bcm2835_devm_add_vchi_ctx(dev);
+       if (err)
+               return err;
+
        err = snd_add_child_devices(dev, numchans);
        if (err)
                return err;

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h
index dc6ec915f9f585c60e21ddb18869339a1d49ff7d..5dc427240a1d759b2df64a8560ebf5eba59f5454 100644 (file)
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h
@@ -15,6 +15,8 @@
 #include <sound/pcm-indirect.h>
 #include <linux/workqueue.h>
 
+#include "interface/vchi/vchi.h"
+
 /*
  * #define AUDIO_DEBUG_ENABLE
  * #define AUDIO_VERBOSE_DEBUG_ENABLE
@@ -86,6 +88,11 @@ enum snd_bcm2835_ctrl {
        PCM_PLAYBACK_DEVICE,
 };
 
+struct bcm2835_vchi_ctx {
+       VCHI_INSTANCE_T vchi_instance;
+       VCHI_CONNECTION_T *vchi_connection;
+};
+
 /* definition of the chip-specific record */
 struct bcm2835_chip {
        struct snd_card *card;
@@ -104,6 +111,8 @@ struct bcm2835_chip {
        unsigned int opened;
        unsigned int spdif_status;
        struct mutex audio_mutex;
+
+       struct bcm2835_vchi_ctx *vchi_ctx;
 };
 
 struct bcm2835_alsa_stream {
@@ -142,6 +151,9 @@ int snd_bcm2835_new_simple_pcm(struct bcm2835_chip *chip,
 int snd_bcm2835_new_hdmi_ctl(struct bcm2835_chip *chip);
 int snd_bcm2835_new_headphones_ctl(struct bcm2835_chip *chip);
 
+int bcm2835_new_vchi_ctx(struct bcm2835_vchi_ctx *vchi_ctx);
+void bcm2835_free_vchi_ctx(struct bcm2835_vchi_ctx *vchi_ctx);
+
 int bcm2835_audio_open(struct bcm2835_alsa_stream *alsa_stream);
 int bcm2835_audio_close(struct bcm2835_alsa_stream *alsa_stream);
 int bcm2835_audio_set_params(struct bcm2835_alsa_stream *alsa_stream,