From 36c0ec31f502c373aa3860518fa82ed931115f66 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 28 Mar 2006 17:58:28 +0200
Subject: [PATCH] --- yaml --- r: 25262 b: refs/heads/master c:
 14790f1c73cfa4d4a22ac10b4501b4831380683c h: refs/heads/master v: v3

---
 [refs]                     |  2 +-
 trunk/sound/usb/usbmixer.c | 37 ++++++++++++++++++++++++++++++++++---
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index 909eeb9dd490..f3891ab1486a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0b2dcd5d6a9a3e27fdd67053e526388f9f2ea33b
+refs/heads/master: 14790f1c73cfa4d4a22ac10b4501b4831380683c
diff --git a/trunk/sound/usb/usbmixer.c b/trunk/sound/usb/usbmixer.c
index 8d08b34a1cb5..ce86283ee0fa 100644
--- a/trunk/sound/usb/usbmixer.c
+++ b/trunk/sound/usb/usbmixer.c
@@ -306,8 +306,8 @@ static int get_relative_value(struct usb_mixer_elem_info *cval, int val)
 		cval->res = 1;
 	if (val < cval->min)
 		return 0;
-	else if (val > cval->max)
-		return (cval->max - cval->min) / cval->res;
+	else if (val >= cval->max)
+		return (cval->max - cval->min + cval->res - 1) / cval->res;
 	else
 		return (val - cval->min) / cval->res;
 }
@@ -670,6 +670,36 @@ static int get_min_max(struct usb_mixer_elem_info *cval, int default_min)
 		}
 		if (cval->res == 0)
 			cval->res = 1;
+
+		/* Additional checks for the proper resolution
+		 *
+		 * Some devices report smaller resolutions than actually
+		 * reacting.  They don't return errors but simply clip
+		 * to the lower aligned value.
+		 */
+		if (cval->min + cval->res < cval->max) {
+			int last_valid_res = cval->res;
+			int saved, test, check;
+			get_cur_mix_value(cval, minchn, &saved);
+			for (;;) {
+				test = saved;
+				if (test < cval->max)
+					test += cval->res;
+				else
+					test -= cval->res;
+				if (test < cval->min || test > cval->max ||
+				    set_cur_mix_value(cval, minchn, test) ||
+				    get_cur_mix_value(cval, minchn, &check)) {
+					cval->res = last_valid_res;
+					break;
+				}
+				if (test == check)
+					break;
+				cval->res *= 2;
+			}
+			set_cur_mix_value(cval, minchn, saved);
+		}
+
 		cval->initialized = 1;
 	}
 	return 0;
@@ -695,7 +725,8 @@ static int mixer_ctl_feature_info(struct snd_kcontrol *kcontrol, struct snd_ctl_
 		if (! cval->initialized)
 			get_min_max(cval,  0);
 		uinfo->value.integer.min = 0;
-		uinfo->value.integer.max = (cval->max - cval->min) / cval->res;
+		uinfo->value.integer.max =
+			(cval->max - cval->min + cval->res - 1) / cval->res;
 	}
 	return 0;
 }