At Fri, 05 Sep 2014 16:37:13 +0200, Jurgen Kramer wrote:
On Fri, 2014-09-05 at 16:27 +0200, Takashi Iwai wrote:
At Fri, 05 Sep 2014 15:58:39 +0200, Jurgen Kramer wrote:
On Fri, 2014-09-05 at 15:36 +0200, Takashi Iwai wrote:
At Fri, 5 Sep 2014 14:24:57 +0200, Jurgen Kramer wrote:
Add quirks for XMOS based DACs for native DSD playback support using the new DSD_U32_LE sample format.
This version adds native DSD support for:
- iFi Audio micro iDSD/nano iDSD (they use the same prod. id)
- DIYINHK USB to I2S/DSD converter
Changes from v1:
- use specific product id and alt setting per XMOS based device
Signed-off-by: Jurgen Kramer gtmkramer@xs4all.nl
sound/usb/quirks.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index 19a921e..5ae0536 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -1174,5 +1174,20 @@ u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip, } }
- /* XMOS based USB DACs */
- if (le16_to_cpu(chip->dev->descriptor.idVendor) == 0x20b1) {
switch (le16_to_cpu(chip->dev->descriptor.idProduct)) {/* iFi Audio micro/nano iDSD */case 0x3008:if (fp->altsetting == 2)return SNDRV_PCM_FMTBIT_DSD_U32_LE;Missing break?
It is already returning. Where would the break go?
What if fp->altsetting == 3 with 20b1:3008 chip? Then it falls down to below, and return SNDRV_PCM_FMTBIT_DSD_U32_LE. Is this expected?
With fp->altsetting == 3 for 20b1:3008 I do not see it returning SNDRV_PCM_FMTBIT_DSD_U32_LE, it falls through to 'return 0'.
Well, read your C text book carefully again :)
The tricky part of switch/case behavior is that it falls through to the next case, not going out of switch block.
However, would this be more appropriate/readable?:
case 0x3008: if (fp->altsetting == 2) return SNDRV_PCM_FMTBIT_DSD_U32_LE; else break;
Just put break. The standard form of switch/case is like:
switch (cond) { case xxx: if (something) return abc; break; case yyy: if (another) return def; break; default: break; }
return 0;
Takashi
or even:
case 0x3008: if (fp->altsetting == 2) return SNDRV_PCM_FMTBIT_DSD_U32_LE; else return 0;
/* DIYINHK DSD DXD 384kHz USB to I2S/DSD */case 0x2009:if (fp->altsetting == 3)return SNDRV_PCM_FMTBIT_DSD_U32_LE;Ditto.
See above.
If the fallthrough is intentional, you *must* put a comment it's really a fallthrough.
Jurgen