[alsa-devel] Removal of indirect access in control API

[Takashi Iwai]

Hi,

ALSA control elements have "indirect" flag, which is supposed to allow
the indirect access via pointer.  But, as far as I know, this feature
has never been used nor implemented, and unsupported via 32/64bit
compat layer.

So, I'd like to get rid of this now.  The clean-up patch is below.

If you have objections, please let me know.


thanks,

Takashi

---

diff -r 34e3c66d7a5c core/control.c
--- a/core/control.c	Mon Nov 12 18:04:54 2007 +0100
+++ b/core/control.c	Mon Nov 12 18:05:16 2007 +0100
@@ -232,8 +232,6 @@ struct snd_kcontrol *snd_ctl_new1(const 
 	access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 		 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 				      SNDRV_CTL_ELEM_ACCESS_INACTIVE|
-		 		      SNDRV_CTL_ELEM_ACCESS_DINDIRECT|
-		 		      SNDRV_CTL_ELEM_ACCESS_INDIRECT|
 		 		      SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 		 		      SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 	kctl.info = ncontrol->info;
@@ -692,7 +690,7 @@ int snd_ctl_elem_read(struct snd_card *c
 	struct snd_kcontrol *kctl;
 	struct snd_kcontrol_volatile *vd;
 	unsigned int index_offset;
-	int result, indirect;
+	int result;
 
 	down_read(&card->controls_rwsem);
 	kctl = snd_ctl_find_id(card, &control->id);
@@ -701,17 +699,12 @@ int snd_ctl_elem_read(struct snd_card *c
 	} else {
 		index_offset = snd_ctl_get_ioff(kctl, &control->id);
 		vd = &kctl->vd[index_offset];
-		indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
-		if (control->indirect != indirect) {
-			result = -EACCES;
-		} else {
-			if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
-				snd_ctl_build_ioff(&control->id, kctl, index_offset);
-				result = kctl->get(kctl, control);
-			} else {
-				result = -EPERM;
-			}
-		}
+		if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
+		    kctl->get != NULL) {
+			snd_ctl_build_ioff(&control->id, kctl, index_offset);
+			result = kctl->get(kctl, control);
+		} else
+			result = -EPERM;
 	}
 	up_read(&card->controls_rwsem);
 	return result;
@@ -748,7 +741,7 @@ int snd_ctl_elem_write(struct snd_card *
 	struct snd_kcontrol *kctl;
 	struct snd_kcontrol_volatile *vd;
 	unsigned int index_offset;
-	int result, indirect;
+	int result;
 
 	down_read(&card->controls_rwsem);
 	kctl = snd_ctl_find_id(card, &control->id);
@@ -757,23 +750,19 @@ int snd_ctl_elem_write(struct snd_card *
 	} else {
 		index_offset = snd_ctl_get_ioff(kctl, &control->id);
 		vd = &kctl->vd[index_offset];
-		indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
-		if (control->indirect != indirect) {
-			result = -EACCES;
+		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
+		    kctl->put == NULL ||
+		    (file && vd->owner && vd->owner != file)) {
+			result = -EPERM;
 		} else {
-			if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
-			    kctl->put == NULL ||
-			    (file && vd->owner != NULL && vd->owner != file)) {
-				result = -EPERM;
-			} else {
-				snd_ctl_build_ioff(&control->id, kctl, index_offset);
-				result = kctl->put(kctl, control);
-			}
-			if (result > 0) {
-				up_read(&card->controls_rwsem);
-				snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
-				return 0;
-			}
+			snd_ctl_build_ioff(&control->id, kctl, index_offset);
+			result = kctl->put(kctl, control);
+		}
+		if (result > 0) {
+			up_read(&card->controls_rwsem);
+			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
+				       &control->id);
+			return 0;
 		}
 	}
 	up_read(&card->controls_rwsem);
diff -r 34e3c66d7a5c include/asound.h
--- a/include/asound.h	Mon Nov 12 18:04:54 2007 +0100
+++ b/include/asound.h	Mon Nov 12 18:05:16 2007 +0100
@@ -738,8 +738,7 @@ typedef int __bitwise snd_ctl_elem_iface
 #define SNDRV_CTL_ELEM_ACCESS_OWNER		(1<<10)	/* write lock owner */
 #define SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK	(1<<28)	/* kernel use a TLV callback */ 
 #define SNDRV_CTL_ELEM_ACCESS_USER		(1<<29) /* user space element */
-#define SNDRV_CTL_ELEM_ACCESS_DINDIRECT		(1<<30)	/* indirect access for matrix dimensions in the info structure */
-#define SNDRV_CTL_ELEM_ACCESS_INDIRECT		(1<<31)	/* indirect access for element value in the value structure */
+/* bits 30 and 31 are obsoleted (for indirect access) */
 
 /* for further details see the ACPI and PCI power management specification */
 #define SNDRV_CTL_POWER_D0		0x0000	/* full On */
@@ -793,30 +792,25 @@ struct snd_ctl_elem_info {
 	} value;
 	union {
 		unsigned short d[4];		/* dimensions */
-		unsigned short *d_ptr;		/* indirect */
 	} dimen;
 	unsigned char reserved[64-4*sizeof(unsigned short)];
 };
 
 struct snd_ctl_elem_value {
 	struct snd_ctl_elem_id id;	/* W: element ID */
-	unsigned int indirect: 1;	/* W: use indirect pointer (xxx_ptr member) */
+	unsigned int indirect: 1;	/* W: indirect access - obsoleted */
         union {
 		union {
 			long value[128];
-			long *value_ptr;
 		} integer;
 		union {
 			long long value[64];
-			long long *value_ptr;
 		} integer64;
 		union {
 			unsigned int item[128];
-			unsigned int *item_ptr;
 		} enumerated;
 		union {
 			unsigned char data[512];
-			unsigned char *data_ptr;
 		} bytes;
 		struct snd_aes_iec958 iec958;
         } value;                /* RO */