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authorTakashi Sakamoto <o-takashi@sakamocchi.jp>2017-08-03 20:20:43 +0900
committerTakashi Iwai <tiwai@suse.de>2017-08-04 16:50:56 +0200
commit450296f305f139ccb363657efcea439afa4e762a (patch)
tree588a6b7d4625b445d98221c9dd776a75ea9f2255 /sound/core
parent30d8340b5857550007ab6fe9744e4384dfa6e55c (diff)
ALSA: control: code refactoring TLV ioctl handler
In a design of ALSA control core, execution path bifurcates depending on target element. When a set with the target element has a handler, it's called. Else, registered buffer is copied to user space. These two operations are apparently different. In current implementation, they're on the same function with a condition statement. This makes it a bit hard to understand conditions of each case. This commit splits codes for these two cases. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
-rw-r--r--sound/core/control.c132
1 files changed, 91 insertions, 41 deletions
diff --git a/sound/core/control.c b/sound/core/control.c
index 989292fe33c2..92389000f0df 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1394,65 +1394,115 @@ static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
return 0;
}
+static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
+ struct snd_kcontrol *kctl,
+ struct snd_ctl_elem_id *id,
+ unsigned int __user *buf, unsigned int size)
+{
+ static const struct {
+ int op;
+ int perm;
+ } pairs[] = {
+ {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
+ {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
+ {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
+ };
+ struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
+ int i;
+ int err;
+
+ /* Check support of the request for this element. */
+ for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
+ if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
+ break;
+ }
+ if (i == ARRAY_SIZE(pairs))
+ return -ENXIO;
+
+ if (kctl->tlv.c == NULL)
+ return -ENXIO;
+
+ /* When locked, this is unavailable. */
+ if (vd->owner != NULL && vd->owner != file)
+ return -EPERM;
+
+ err = kctl->tlv.c(kctl, op_flag, size, buf);
+ if (err < 0)
+ return err;
+
+ if (err > 0)
+ snd_ctl_notify(file->card, SNDRV_CTL_EVENT_MASK_TLV, id);
+
+ return 0;
+}
+
+static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
+ unsigned int __user *buf, unsigned int size)
+{
+ struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
+ unsigned int len;
+
+ if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
+ return -ENXIO;
+
+ if (kctl->tlv.p == NULL)
+ return -ENXIO;
+
+ len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
+ if (size < len)
+ return -ENOMEM;
+
+ if (copy_to_user(buf, kctl->tlv.p, len))
+ return -EFAULT;
+
+ return 0;
+}
+
static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
- struct snd_ctl_tlv __user *_tlv,
+ struct snd_ctl_tlv __user *buf,
int op_flag)
{
- struct snd_card *card = file->card;
- struct snd_ctl_tlv tlv;
+ struct snd_ctl_tlv header;
+ unsigned int *container;
+ unsigned int container_size;
struct snd_kcontrol *kctl;
+ struct snd_ctl_elem_id id;
struct snd_kcontrol_volatile *vd;
- unsigned int len;
- if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
+ if (copy_from_user(&header, buf, sizeof(header)))
return -EFAULT;
- if (tlv.length < sizeof(unsigned int) * 2)
+
+ /* In design of control core, numerical ID starts at 1. */
+ if (header.numid == 0)
return -EINVAL;
- if (!tlv.numid)
+
+ /* At least, container should include type and length fields. */
+ if (header.length < sizeof(unsigned int) * 2)
return -EINVAL;
+ container_size = header.length;
+ container = buf->tlv;
- kctl = snd_ctl_find_numid(card, tlv.numid);
+ kctl = snd_ctl_find_numid(file->card, header.numid);
if (kctl == NULL)
return -ENOENT;
- if (kctl->tlv.p == NULL)
- return -ENXIO;
-
- vd = &kctl->vd[tlv.numid - kctl->id.numid];
- if ((op_flag == SNDRV_CTL_TLV_OP_READ &&
- (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
- (op_flag == SNDRV_CTL_TLV_OP_WRITE &&
- (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
- (op_flag == SNDRV_CTL_TLV_OP_CMD &&
- (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0))
- return -ENXIO;
+ /* Calculate index of the element in this set. */
+ id = kctl->id;
+ snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
+ vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
- int err;
-
- if (vd->owner != NULL && vd->owner != file)
- return -EPERM;
-
- err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
- if (err < 0)
- return err;
- if (err > 0) {
- struct snd_ctl_elem_id id = kctl->id;
- snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
- }
+ return call_tlv_handler(file, op_flag, kctl, &id, container,
+ container_size);
} else {
- if (op_flag != SNDRV_CTL_TLV_OP_READ)
- return -ENXIO;
-
- len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
- if (tlv.length < len)
- return -ENOMEM;
-
- if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
- return -EFAULT;
+ if (op_flag == SNDRV_CTL_TLV_OP_READ) {
+ return read_tlv_buf(kctl, &id, container,
+ container_size);
+ }
}
- return 0;
+ /* Not supported. */
+ return -ENXIO;
}
static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)