diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 02298c9..4414050 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -1326,7 +1326,7 @@ static ssize_t snd_pcm_oss_write2(struct snd_pcm_substream *substream, const cha
 static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const char __user *buf, size_t bytes)
 {
 	size_t xfer = 0;
-	ssize_t tmp;
+	ssize_t tmp = 0;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 
 	if (atomic_read(&substream->mmap_count))
@@ -1433,7 +1433,7 @@ static ssize_t snd_pcm_oss_read2(struct snd_pcm_substream *substream, char *buf,
 static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __user *buf, size_t bytes)
 {
 	size_t xfer = 0;
-	ssize_t tmp;
+	ssize_t tmp = 0;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 
 	if (atomic_read(&substream->mmap_count))
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 77ba50d..d18b398 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3422,7 +3422,7 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream,
 					 area,
 					 substream->runtime->dma_area,
 					 substream->runtime->dma_addr,
-					 area->vm_end - area->vm_start);
+					 substream->runtime->dma_bytes);
 #endif /* CONFIG_X86 */
 	/* mmap with fault handler */
 	area->vm_ops = &snd_pcm_vm_ops_data_fault;
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index ea8f3de..794224e 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -1171,6 +1171,7 @@ static bool is_teac_dsd_dac(unsigned int id)
 	switch (id) {
 	case USB_ID(0x0644, 0x8043): /* TEAC UD-501/UD-503/NT-503 */
 	case USB_ID(0x0644, 0x8044): /* Esoteric D-05X */
+	case USB_ID(0x0644, 0x804a): /* TEAC UD-301 */
 		return true;
 	}
 	return false;