Re: [alsa-devel] [PATCH 06/10] ALSA: usb-audio: UAC2: do clock validity check earlier

At Sun, 31 Mar 2013 17:52:28 +0200, Eldad Zack wrote:

Move the check that parse_audio_format_rates_v2() do after receiving the clock source entity ID directly into the find function and add a validation flag to the function.

This patch does not introduce any logic flow change.

Please give a few more words why this change is introduced.

thanks,

Takashi

Signed-off-by: Eldad Zack eldad@fogrefinery.com

sound/usb/clock.c | 35 +++++++++++++++++++---------------- sound/usb/clock.h | 3 ++- sound/usb/format.c | 2 +- 3 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/sound/usb/clock.c b/sound/usb/clock.c index 47b601d..08fa345 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -131,7 +131,8 @@ static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id) }

static int __uac_clock_find_source(struct snd_usb_audio *chip,

• 		   int entity_id, unsigned long *visited)
  

• 		   int entity_id, unsigned long *visited,
  

• 		   bool validate)
  

{ struct uac_clock_source_descriptor *source; struct uac_clock_selector_descriptor *selector; @@ -148,8 +149,15 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip,

/* first, see if the ID we're looking for is a clock source already */ source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);

• if (source)

• return source->bClockID;
  

• if (source) {

• entity_id = source->bClockID;
  

• if (validate && !uac_clock_source_is_valid(chip, entity_id)) {
  

• 	snd_printk(KERN_ERR "usb-audio:%d: clock source %d is not valid, cannot use\n",
  

• 		   chip->dev->devnum, entity_id);
  

• 	return -ENXIO;
  

• }
  

• return entity_id;
  

• }

  selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id); if (selector) {

@@ -164,7 +172,7 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip, /* Selector values are one-based */

if (ret > selector->bNrInPins || ret < 1) {

• 	printk(KERN_ERR
  

• 	snd_printk(KERN_ERR
  	"%s(): selector reported illegal value, id %d, ret %d\n",
  	__func__, selector->bClockID, ret);
  
  

@@ -172,14 +180,14 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip, }

return __uac_clock_find_source(chip, selector->baCSourceID[ret-1],

• 			       visited);
  

• 			       visited, validate);
  

  }

  /* FIXME: multipliers only act as pass-thru element for now */ multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id); if (multiplier) return __uac_clock_find_source(chip, multiplier->bCSourceID,

• 				visited);
  

• 				visited, validate);
  
  

  return -EINVAL;

} @@ -195,11 +203,12 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip,

• Returns the clock source UnitID (>=0) on success, or an error.

*/ -int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id) +int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id,

• 	      bool validate)
  

{ DECLARE_BITMAP(visited, 256); memset(visited, 0, sizeof(visited));

• return __uac_clock_find_source(chip, entity_id, visited);

• return __uac_clock_find_source(chip, entity_id, visited, validate);

}

static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface, @@ -254,18 +263,12 @@ static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface, struct usb_device *dev = chip->dev; u32 data; int err, crate;

• int clock = snd_usb_clock_find_source(chip, fmt->clock);

• int clock;

• clock = snd_usb_clock_find_source(chip, fmt->clock, true); if (clock < 0) return clock;

• if (!uac_clock_source_is_valid(chip, clock)) {

• /* TODO: should we try to find valid clock setups by ourself? */
  

• snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
  

• 	   dev->devnum, iface, fmt->altsetting, clock);
  

• return -ENXIO;
  

• }
• data = cpu_to_le32(rate); if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR, USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,

diff --git a/sound/usb/clock.h b/sound/usb/clock.h index 4663093..d592e4a 100644 --- a/sound/usb/clock.h +++ b/sound/usb/clock.h @@ -5,6 +5,7 @@ int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface, struct usb_host_interface *alts, struct audioformat *fmt, int rate);

-int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id); +int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id,

• 	     bool validate);
  
  

#endif /* __USBAUDIO_CLOCK_H */ diff --git a/sound/usb/format.c b/sound/usb/format.c index e831ee4..1086b87 100644 --- a/sound/usb/format.c +++ b/sound/usb/format.c @@ -277,7 +277,7 @@ static int parse_audio_format_rates_v2(struct snd_usb_audio *chip, struct usb_device *dev = chip->dev; unsigned char tmp[2], *data; int nr_triplets, data_size, ret = 0;

• int clock = snd_usb_clock_find_source(chip, fp->clock);

• int clock = snd_usb_clock_find_source(chip, fp->clock, false);

  if (clock < 0) { snd_printk(KERN_ERR "%s(): unable to find clock source (clock %d)\n",

-- 1.8.1.5