修改led为gpio

hc

2024-10-12 a5969cabbb4660eab42b6ef0412cbbd1200cf14d

 kernel/sound/core/pcm_memory.c
..
..
@@ -31,20 +31,51 @@
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 module_param(max_alloc_per_card, ulong, 0644);
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 MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");
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+static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
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+{
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+	card->total_pcm_alloc_bytes += bytes;
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+}
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+
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+static void update_allocated_size(struct snd_card *card, ssize_t bytes)
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+{
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+	mutex_lock(&card->memory_mutex);
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+	__update_allocated_size(card, bytes);
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+	mutex_unlock(&card->memory_mutex);
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+}
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+
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+static void decrease_allocated_size(struct snd_card *card, size_t bytes)
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+{
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+	mutex_lock(&card->memory_mutex);
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+	WARN_ON(card->total_pcm_alloc_bytes < bytes);
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+	__update_allocated_size(card, -(ssize_t)bytes);
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+	mutex_unlock(&card->memory_mutex);
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+}
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+
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 static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
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 			  size_t size, struct snd_dma_buffer *dmab)
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 {
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 	int err;
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+	/* check and reserve the requested size */
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+	mutex_lock(&card->memory_mutex);
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 	if (max_alloc_per_card &&
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-	    card->total_pcm_alloc_bytes + size > max_alloc_per_card)
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+	    card->total_pcm_alloc_bytes + size > max_alloc_per_card) {
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+		mutex_unlock(&card->memory_mutex);
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 		return -ENOMEM;
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+	}
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+	__update_allocated_size(card, size);
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+	mutex_unlock(&card->memory_mutex);
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 	err = snd_dma_alloc_pages(type, dev, size, dmab);
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 	if (!err) {
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-		mutex_lock(&card->memory_mutex);
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-		card->total_pcm_alloc_bytes += dmab->bytes;
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-		mutex_unlock(&card->memory_mutex);
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+		/* the actual allocation size might be bigger than requested,
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+		 * and we need to correct the account
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+		 */
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+		if (dmab->bytes != size)
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+			update_allocated_size(card, dmab->bytes - size);
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+	} else {
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+		/* take back on allocation failure */
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+		decrease_allocated_size(card, size);
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 	}
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 	return err;
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 }
..
..
@@ -53,10 +84,7 @@
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 {
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 	if (!dmab->area)
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 		return;
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-	mutex_lock(&card->memory_mutex);
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-	WARN_ON(card->total_pcm_alloc_bytes < dmab->bytes);
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-	card->total_pcm_alloc_bytes -= dmab->bytes;
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-	mutex_unlock(&card->memory_mutex);
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+	decrease_allocated_size(card, dmab->bytes);
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 	snd_dma_free_pages(dmab);
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 	dmab->area = NULL;
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 }