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ALSA: Update description of snd_card_create() in documents 

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2008-12-28 16:45:34 +01:00 committed by Takashi Iwai
parent bd7dd77c2a
commit d453379bc5
1 changed files with 25 additions and 19 deletions
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44
Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
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@ -492,9 +492,9 @@
}
/* (2) */
card = snd_card_new(index[dev], id[dev], THIS_MODULE, 0);
if (card == NULL)
return -ENOMEM;
err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card);
if (err < 0)
return err;
/* (3) */
err = snd_mychip_create(card, pci, &chip);
@ -590,8 +590,9 @@
<programlisting>
<![CDATA[
struct snd_card *card;
int err;
....
card = snd_card_new(index[dev], id[dev], THIS_MODULE, 0);
err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card);
]]>
</programlisting>
</informalexample>
@ -809,26 +810,28 @@
<para>
As mentioned above, to create a card instance, call
<function>snd_card_new()</function>.
<function>snd_card_create()</function>.
<informalexample>
<programlisting>
<![CDATA[
struct snd_card *card;
card = snd_card_new(index, id, module, extra_size);
int err;
err = snd_card_create(index, id, module, extra_size, &card);
]]>
</programlisting>
</informalexample>
</para>
<para>
The function takes four arguments, the card-index number, the
The function takes five arguments, the card-index number, the
id string, the module pointer (usually
<constant>THIS_MODULE</constant>),
and the size of extra-data space. The last argument is used to
the size of extra-data space, and the pointer to return the
card instance. The extra_size argument is used to
allocate card-&gt;private_data for the
chip-specific data. Note that these data
are allocated by <function>snd_card_new()</function>.
are allocated by <function>snd_card_create()</function>.
</para>
</section>
@ -915,15 +918,16 @@
</para>
<section id="card-management-chip-specific-snd-card-new">
<title>1. Allocating via <function>snd_card_new()</function>.</title>
<title>1. Allocating via <function>snd_card_create()</function>.</title>
<para>
As mentioned above, you can pass the extra-data-length
to the 4th argument of <function>snd_card_new()</function>, i.e.
to the 4th argument of <function>snd_card_create()</function>, i.e.
<informalexample>
<programlisting>
<![CDATA[
card = snd_card_new(index[dev], id[dev], THIS_MODULE, sizeof(struct mychip));
err = snd_card_create(index[dev], id[dev], THIS_MODULE,
sizeof(struct mychip), &card);
]]>
</programlisting>
</informalexample>
@ -952,8 +956,8 @@
<para>
After allocating a card instance via
<function>snd_card_new()</function> (with
<constant>NULL</constant> on the 4th arg), call
<function>snd_card_create()</function> (with
<constant>0</constant> on the 4th arg), call
<function>kzalloc()</function>.
<informalexample>
@ -961,7 +965,7 @@
<![CDATA[
struct snd_card *card;
struct mychip *chip;
card = snd_card_new(index[dev], id[dev], THIS_MODULE, NULL);
err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card);
.....
chip = kzalloc(sizeof(*chip), GFP_KERNEL);
]]>
@ -5750,8 +5754,9 @@ struct _snd_pcm_runtime {
....
struct snd_card *card;
struct mychip *chip;
int err;
....
card = snd_card_new(index[dev], id[dev], THIS_MODULE, NULL);
err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card);
....
chip = kzalloc(sizeof(*chip), GFP_KERNEL);
....
@ -5763,7 +5768,7 @@ struct _snd_pcm_runtime {
</informalexample>
When you created the chip data with
<function>snd_card_new()</function>, it's anyway accessible
<function>snd_card_create()</function>, it's anyway accessible
via <structfield>private_data</structfield> field.
<informalexample>
@ -5775,9 +5780,10 @@ struct _snd_pcm_runtime {
....
struct snd_card *card;
struct mychip *chip;
int err;
....
card = snd_card_new(index[dev], id[dev], THIS_MODULE,
sizeof(struct mychip));
err = snd_card_create(index[dev], id[dev], THIS_MODULE,
sizeof(struct mychip), &card);
....
chip = card->private_data;
....