[alsa-devel] [PATCH 1/2] ALSA: usb-audio: Refactor clock finder helpers
Takashi Iwai
tiwai at suse.de
Tue Apr 3 20:02:45 CEST 2018
On Tue, 03 Apr 2018 19:13:51 +0200,
Andrew Chant wrote:
>
> On Tue, Apr 3, 2018 at 8:48 AM, Takashi Iwai <tiwai at suse.de> wrote:
> >
> > There are lots of open-coded functions to find a clock source,
> > selector and multiplier. Now there are both v2 and v3, so six
> > variants.
> >
> > This patch refactors the code to use a common helper for the main
> > loop, and define each validator function for each target.
> > There is no functional change.
> >
> > Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support")
> > Signed-off-by: Takashi Iwai <tiwai at suse.de>
> > ---
> > sound/usb/clock.c | 127 +++++++++++++++++++++++-------------------------------
> > 1 file changed, 53 insertions(+), 74 deletions(-)
> >
> > diff --git a/sound/usb/clock.c b/sound/usb/clock.c
> > index ab39ccb974c6..c5f0cf532c0c 100644
> > --- a/sound/usb/clock.c
> > +++ b/sound/usb/clock.c
> > @@ -35,105 +35,84 @@
> > #include "clock.h"
> > #include "quirks.h"
> >
> > -static struct uac_clock_source_descriptor *
> > - snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
> > - int clock_id)
> > +static void *find_descriptor(struct usb_host_interface *iface, int id,
> > + bool (*validator)(void *, int), u8 type)
>
> this comment isn't very important, and might be wrong:
> find_descriptor is a very generic name, it might make grepping a
> little confusing.
> Could you use find_clock_descriptor? find_uac_clock_descriptor?
Makes sense. Now I renamed it with a bit shorter one,
find_uac_clock_desc(). The revised patch is below.
thanks,
Takashi
-- 8< --
From: Takashi Iwai <tiwai at suse.de>
Subject: [PATCH v2 1/2] ALSA: usb-audio: Refactor clock finder helpers
There are lots of open-coded functions to find a clock source,
selector and multiplier. Now there are both v2 and v3, so six
variants.
This patch refactors the code to use a common helper for the main
loop, and define each validator function for each target.
There is no functional change.
Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support")
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
v1->v2: rename find_descriptor() with find_uac_clock_desc()
sound/usb/clock.c | 127 +++++++++++++++++++++++-------------------------------
1 file changed, 53 insertions(+), 74 deletions(-)
diff --git a/sound/usb/clock.c b/sound/usb/clock.c
index ab39ccb974c6..27c2275a2505 100644
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -35,105 +35,84 @@
#include "clock.h"
#include "quirks.h"
-static struct uac_clock_source_descriptor *
- snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
- int clock_id)
+static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
+ bool (*validator)(void *, int), u8 type)
{
- struct uac_clock_source_descriptor *cs = NULL;
+ void *cs = NULL;
- while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
- ctrl_iface->extralen,
- cs, UAC2_CLOCK_SOURCE))) {
- if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)
+ while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
+ cs, type))) {
+ if (validator(cs, id))
return cs;
}
return NULL;
}
-static struct uac3_clock_source_descriptor *
- snd_usb_find_clock_source_v3(struct usb_host_interface *ctrl_iface,
- int clock_id)
+static bool validate_clock_source_v2(void *p, int id)
{
- struct uac3_clock_source_descriptor *cs = NULL;
-
- while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
- ctrl_iface->extralen,
- cs, UAC3_CLOCK_SOURCE))) {
- if (cs->bClockID == clock_id)
- return cs;
- }
-
- return NULL;
+ struct uac_clock_source_descriptor *cs = p;
+ return cs->bLength >= sizeof(*cs) && cs->bClockID == id;
}
-static struct uac_clock_selector_descriptor *
- snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
- int clock_id)
+static bool validate_clock_source_v3(void *p, int id)
{
- struct uac_clock_selector_descriptor *cs = NULL;
-
- while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
- ctrl_iface->extralen,
- cs, UAC2_CLOCK_SELECTOR))) {
- if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id) {
- if (cs->bLength < 5 + cs->bNrInPins)
- return NULL;
- return cs;
- }
- }
-
- return NULL;
+ struct uac3_clock_source_descriptor *cs = p;
+ return cs->bClockID == id;
}
-static struct uac3_clock_selector_descriptor *
- snd_usb_find_clock_selector_v3(struct usb_host_interface *ctrl_iface,
- int clock_id)
+static bool validate_clock_selector_v2(void *p, int id)
{
- struct uac3_clock_selector_descriptor *cs = NULL;
-
- while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
- ctrl_iface->extralen,
- cs, UAC3_CLOCK_SELECTOR))) {
- if (cs->bClockID == clock_id)
- return cs;
- }
-
- return NULL;
+ struct uac_clock_selector_descriptor *cs = p;
+ return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&
+ cs->bLength >= 5 + cs->bNrInPins;
}
-static struct uac_clock_multiplier_descriptor *
- snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
- int clock_id)
+static bool validate_clock_selector_v3(void *p, int id)
{
- struct uac_clock_multiplier_descriptor *cs = NULL;
-
- while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
- ctrl_iface->extralen,
- cs, UAC2_CLOCK_MULTIPLIER))) {
- if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)
- return cs;
- }
-
- return NULL;
+ struct uac3_clock_selector_descriptor *cs = p;
+ return cs->bClockID == id;
}
-static struct uac3_clock_multiplier_descriptor *
- snd_usb_find_clock_multiplier_v3(struct usb_host_interface *ctrl_iface,
- int clock_id)
+static bool validate_clock_multiplier_v2(void *p, int id)
{
- struct uac3_clock_multiplier_descriptor *cs = NULL;
+ struct uac_clock_multiplier_descriptor *cs = p;
+ return cs->bLength >= sizeof(*cs) && cs->bClockID == id;
+}
- while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
- ctrl_iface->extralen,
- cs, UAC3_CLOCK_MULTIPLIER))) {
- if (cs->bClockID == clock_id)
- return cs;
- }
+static bool validate_clock_multiplier_v3(void *p, int id)
+{
+ struct uac3_clock_multiplier_descriptor *cs = p;
+ return cs->bClockID == id;
+}
- return NULL;
+#define DEFINE_FIND_HELPER(name, obj, validator, type) \
+static obj *name(struct usb_host_interface *iface, int id) \
+{ \
+ return find_uac_clock_desc(iface, id, validator, type); \
}
+DEFINE_FIND_HELPER(snd_usb_find_clock_source,
+ struct uac_clock_source_descriptor,
+ validate_clock_source_v2, UAC2_CLOCK_SOURCE);
+DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
+ struct uac3_clock_source_descriptor,
+ validate_clock_source_v3, UAC3_CLOCK_SOURCE);
+
+DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
+ struct uac_clock_selector_descriptor,
+ validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
+DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
+ struct uac3_clock_selector_descriptor,
+ validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
+
+DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
+ struct uac_clock_multiplier_descriptor,
+ validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
+DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
+ struct uac3_clock_multiplier_descriptor,
+ validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
+
static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
{
unsigned char buf;
--
2.16.2
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