From bc4e94aa8e72e79598e63a0b73febdcd8aeb541f Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 23 Nov 2020 09:53:07 +0100 Subject: ALSA: usb-audio: Handle discrete rates properly in hw constraints In the current code, when the device provides the discrete sample rate tables with unusual sample rates, the driver tries to gather the whole values from the audioformat entries and create a hw-constraint rule to restrict with this single rate list. This is rather inefficient and may overlook the rates that are associated only with the certain audioformat entries. This patch improves the hw constraint setup by rewriting the existing hw_rule_rate(). The discrete sample rates (identified by rate_table and nr_rates of format entry) are checked in the existing hw_rule_rate() instead of extra rules; in the case of discrete rates, the function compares with each rate table entry and calculates the min/max values from there. For the contiguous rates, the behavior doesn't change. Along with it, snd_usb_pcm_check_knot() and snb_usb_substream rate_list field become superfluous, thus those are dropped. Tested-by: Keith Milner Tested-by: Dylan Robinson Link: https://lore.kernel.org/r/20201123085347.19667-2-tiwai@suse.de Signed-off-by: Takashi Iwai --- sound/usb/card.h | 1 - 1 file changed, 1 deletion(-) (limited to 'sound/usb/card.h') diff --git a/sound/usb/card.h b/sound/usb/card.h index 5351d7183b1b..3cc668f98f43 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -157,7 +157,6 @@ struct snd_usb_substream { u64 formats; /* format bitmasks (all or'ed) */ unsigned int num_formats; /* number of supported audio formats (list) */ struct list_head fmt_list; /* format list */ - struct snd_pcm_hw_constraint_list rate_list; /* limited rates */ spinlock_t lock; int last_frame_number; /* stored frame number */ -- cgit v1.2.3