ALSA: Fix the default suffix string with high card number (8edbb198) · Commits · 戴 / test

ALSA core tries to add a suffix as "_1" automatically when the given id string conflicts. The current code assumes implicitly that the max card number is 16 so that the single hex "_X" suffix can be put. However, with the dynamic device management, the card can be at most 32, so it can put even a non-hex character there. Also, when the max card number is increased in future, this would result in worse. This patch rewrites the code to add the suffix string in a simpler (thus cleaner) way. It can support up to three digits, so it should suffice for most requirements. Signed-off-by:

Takashi Iwai <tiwai@suse.de>

sound/core/init.c

+13 −17

Original line number	Diff line number	Diff line
		@@ -549,7 +549,6 @@ static void snd_card_set_id_no_lock(struct snd_card card, const char src,
		const char *nid)
		{
		int len, loops;
		bool with_suffix;
		bool is_default = false;
		char *id;

		@@ -565,26 +564,23 @@ static void snd_card_set_id_no_lock(struct snd_card card, const char src,
		is_default = true;
		}

		with_suffix = false;
		len = strlen(id);
		for (loops = 0; loops < SNDRV_CARDS; loops++) {
		char *spos;
		char sfxstr[5]; /* "_012" */
		int sfxlen;

		if (card_id_ok(card, id))
		return; /* OK */

		len = strlen(id);
		if (!with_suffix) {
		/* add the "_X" suffix */
		char *spos = id + len;
		if (len > sizeof(card->id) - 3)
		spos = id + sizeof(card->id) - 3;
		strcpy(spos, "_1");
		with_suffix = true;
		} else {
		/* modify the existing suffix */
		if (id[len - 1] != '9')
		id[len - 1]++;
		/* Add _XYZ suffix */
		sprintf(sfxstr, "_%X", loops + 1);
		sfxlen = strlen(sfxstr);
		if (len + sfxlen >= sizeof(card->id))
		spos = id + sizeof(card->id) - sfxlen - 1;
		else
		id[len - 1] = 'A';
		}
		spos = id + len;
		strcpy(spos, sfxstr);
		}
		/* fallback to the default id */
		if (!is_default) {

Admin message