snd_usb_select_mode_quirk(), snd_usb_set_interface_quirk() and snd_usb_ctl_msg_quirk() are never called in atomic context. They call mdelay() to busily wait, which is not necessary. mdelay() can be replaced with msleep() and usleep_range().

This is found by a static analysis tool named DCNS written by myself.

Signed-off-by: Jia-Ju Bai baijiaju1990@gmail.com --- sound/usb/quirks.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index acbeb52f6fd6..9eed650c54d4 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -1181,7 +1181,7 @@ int snd_usb_select_mode_quirk(struct snd_usb_substream *subs, if (err < 0) return err;

- mdelay(20); /* Delay needed after setting the interface */ + msleep(20); /* Delay needed after setting the interface */

/* Vendor mode switch cmd is required. */ if (fmt->formats & SNDRV_PCM_FMTBIT_DSD_U32_BE) { @@ -1202,7 +1202,7 @@ int snd_usb_select_mode_quirk(struct snd_usb_substream *subs, return err;

} - mdelay(20); + msleep(20); } return 0; } @@ -1249,7 +1249,7 @@ void snd_usb_set_interface_quirk(struct usb_device *dev) switch (USB_ID_VENDOR(chip->usb_id)) { case 0x23ba: /* Playback Design */ case 0x0644: /* TEAC Corp. */ - mdelay(50); + msleep(50); break; } } @@ -1269,7 +1269,7 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe, */ if (USB_ID_VENDOR(chip->usb_id) == 0x23ba && (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS) - mdelay(20); + msleep(20);

/* * "TEAC Corp." products need a 20ms delay after each @@ -1277,14 +1277,14 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe, */ if (USB_ID_VENDOR(chip->usb_id) == 0x0644 && (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS) - mdelay(20); + msleep(20);

/* ITF-USB DSD based DACs functionality need a delay * after each class compliant request */ if (is_itf_usb_dsd_dac(chip->usb_id) && (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS) - mdelay(20); + msleep(20);

/* Zoom R16/24, Logitech H650e, Jabra 550a needs a tiny delay here, * otherwise requests like get/set frequency return as failed despite @@ -1294,7 +1294,7 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe, chip->usb_id == USB_ID(0x046d, 0x0a46) || chip->usb_id == USB_ID(0x0b0e, 0x0349)) && (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS) - mdelay(1); + usleep_range(1000, 2000); }

/*