ALSA: caiaq: Use snd_card_free_when_closed() at disconnection

[ Upstream commit b04dcbb7f7b1908806b7dc22671cdbe78ff2b82c ]

The USB disconnect callback is supposed to be short and not too-long
waiting.  OTOH, the current code uses snd_card_free() at
disconnection, but this waits for the close of all used fds, hence it
can take long.  It eventually blocks the upper layer USB ioctls, which
may trigger a soft lockup.

An easy workaround is to replace snd_card_free() with
snd_card_free_when_closed().  This variant returns immediately while
the release of resources is done asynchronously by the card device
release at the last close.

This patch also splits the code to the disconnect and the free phases;
the former is called immediately at the USB disconnect callback while
the latter is called from the card destructor.

Fixes: 523f1dce3743 ("[ALSA] Add Native Instrument usb audio device support")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20241113111042.15058-5-tiwai@suse.de
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/sound/usb/caiaq/audio.c b/sound/usb/caiaq/audio.c
index c6108a3d7f8f8d50e68fc446121155806d0e87fe..9c6a2295d45af916f86f3add3c64521cfb8cba1b 100644 (file)
--- a/sound/usb/caiaq/audio.c
+++ b/sound/usb/caiaq/audio.c
@@ -890,14 +890,20 @@ int snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *cdev)
        return 0;
 }
 
-void snd_usb_caiaq_audio_free(struct snd_usb_caiaqdev *cdev)
+void snd_usb_caiaq_audio_disconnect(struct snd_usb_caiaqdev *cdev)
 {
        struct device *dev = caiaqdev_to_dev(cdev);
 
        dev_dbg(dev, "%s(%p)\n", __func__, cdev);
        stream_stop(cdev);
+}
+
+void snd_usb_caiaq_audio_free(struct snd_usb_caiaqdev *cdev)
+{
+       struct device *dev = caiaqdev_to_dev(cdev);
+
+       dev_dbg(dev, "%s(%p)\n", __func__, cdev);
        free_urbs(cdev->data_urbs_in);
        free_urbs(cdev->data_urbs_out);
        kfree(cdev->data_cb_info);
 }
-

diff --git a/sound/usb/caiaq/audio.h b/sound/usb/caiaq/audio.h
index 869bf6264d6a097fc6c7ab637d8ef55c1c099f74..07f5d064456cf730b4862ad59fb089d1dcc1420d 100644 (file)
--- a/sound/usb/caiaq/audio.h
+++ b/sound/usb/caiaq/audio.h
@@ -3,6 +3,7 @@
 #define CAIAQ_AUDIO_H
 
 int snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *cdev);
+void snd_usb_caiaq_audio_disconnect(struct snd_usb_caiaqdev *cdev);
 void snd_usb_caiaq_audio_free(struct snd_usb_caiaqdev *cdev);
 
 #endif /* CAIAQ_AUDIO_H */

diff --git a/sound/usb/caiaq/device.c b/sound/usb/caiaq/device.c
index d55ca48de3ea3ae7b8c04fad5b3c288e76d7ae27..4df7f37aa670bf2f295c8806e5ce47fc993129db 100644 (file)
--- a/sound/usb/caiaq/device.c
+++ b/sound/usb/caiaq/device.c
@@ -402,6 +402,17 @@ static void setup_card(struct snd_usb_caiaqdev *cdev)
                dev_err(dev, "Unable to set up control system (ret=%d)\n", ret);
 }
 
+static void card_free(struct snd_card *card)
+{
+       struct snd_usb_caiaqdev *cdev = caiaqdev(card);
+
+#ifdef CONFIG_SND_USB_CAIAQ_INPUT
+       snd_usb_caiaq_input_free(cdev);
+#endif
+       snd_usb_caiaq_audio_free(cdev);
+       usb_reset_device(cdev->chip.dev);
+}
+
 static int create_card(struct usb_device *usb_dev,
                       struct usb_interface *intf,
                       struct snd_card **cardp)
@@ -515,6 +526,7 @@ static int init_card(struct snd_usb_caiaqdev *cdev)
                       cdev->vendor_name, cdev->product_name, usbpath);
 
        setup_card(cdev);
+       card->private_free = card_free;
        return 0;
 
  err_kill_urb:
@@ -560,15 +572,14 @@ static void snd_disconnect(struct usb_interface *intf)
        snd_card_disconnect(card);
 
 #ifdef CONFIG_SND_USB_CAIAQ_INPUT
-       snd_usb_caiaq_input_free(cdev);
+       snd_usb_caiaq_input_disconnect(cdev);
 #endif
-       snd_usb_caiaq_audio_free(cdev);
+       snd_usb_caiaq_audio_disconnect(cdev);
 
        usb_kill_urb(&cdev->ep1_in_urb);
        usb_kill_urb(&cdev->midi_out_urb);
 
-       snd_card_free(card);
-       usb_reset_device(interface_to_usbdev(intf));
+       snd_card_free_when_closed(card);
 }
 
 

diff --git a/sound/usb/caiaq/input.c b/sound/usb/caiaq/input.c
index 19951e1dbbb019c767ab8db247d274637507c840..a01a242f5c99562770e272a7be9071f3e7ebfee6 100644 (file)
--- a/sound/usb/caiaq/input.c
+++ b/sound/usb/caiaq/input.c
@@ -842,15 +842,21 @@ exit_free_idev:
        return ret;
 }
 
-void snd_usb_caiaq_input_free(struct snd_usb_caiaqdev *cdev)
+void snd_usb_caiaq_input_disconnect(struct snd_usb_caiaqdev *cdev)
 {
        if (!cdev || !cdev->input_dev)
                return;
 
        usb_kill_urb(cdev->ep4_in_urb);
+       input_unregister_device(cdev->input_dev);
+}
+
+void snd_usb_caiaq_input_free(struct snd_usb_caiaqdev *cdev)
+{
+       if (!cdev || !cdev->input_dev)
+               return;
+
        usb_free_urb(cdev->ep4_in_urb);
        cdev->ep4_in_urb = NULL;
-
-       input_unregister_device(cdev->input_dev);
        cdev->input_dev = NULL;
 }

diff --git a/sound/usb/caiaq/input.h b/sound/usb/caiaq/input.h
index c42891e7be884d9c734df6438120c3136690d7c8..fbe267f85d025fbe0dc4d042fc1c86557305eebf 100644 (file)
--- a/sound/usb/caiaq/input.h
+++ b/sound/usb/caiaq/input.h
@@ -4,6 +4,7 @@
 
 void snd_usb_caiaq_input_dispatch(struct snd_usb_caiaqdev *cdev, char *buf, unsigned int len);
 int snd_usb_caiaq_input_init(struct snd_usb_caiaqdev *cdev);
+void snd_usb_caiaq_input_disconnect(struct snd_usb_caiaqdev *cdev);
 void snd_usb_caiaq_input_free(struct snd_usb_caiaqdev *cdev);
 
 #endif