Commit 84973249 authored by John Keeping's avatar John Keeping Committed by Takashi Iwai
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ALSA: serial-generic: remove shared static buffer 



If multiple instances of this driver are instantiated and try to send
concurrently then the single static buffer snd_serial_generic_tx_work()
will cause corruption in the data output.

Move the buffer into the per-instance driver data to avoid this.

Signed-off-by: default avatarJohn Keeping <jkeeping@inmusicbrands.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent c29287bb

sound/drivers/serial-generic.c

+7 −5
Original line number Diff line number Diff line
@@ -37,6 +37,8 @@ MODULE_LICENSE("GPL"); 
#define SERIAL_TX_STATE_ACTIVE	1

#define SERIAL_TX_STATE_WAKEUP	2



#define INTERNAL_BUF_SIZE 256



struct snd_serial_generic {

	struct serdev_device *serdev;
@@ -51,6 +53,7 @@ struct snd_serial_generic { 
	struct work_struct tx_work;

	unsigned long tx_state;



	char tx_buf[INTERNAL_BUF_SIZE];

};



static void snd_serial_generic_tx_wakeup(struct snd_serial_generic *drvdata)
@@ -61,11 +64,8 @@ static void snd_serial_generic_tx_wakeup(struct snd_serial_generic *drvdata) 
	schedule_work(&drvdata->tx_work);

}



#define INTERNAL_BUF_SIZE 256



static void snd_serial_generic_tx_work(struct work_struct *work)

{

	static char buf[INTERNAL_BUF_SIZE];

	int num_bytes;

	struct snd_serial_generic *drvdata = container_of(work, struct snd_serial_generic,

						   tx_work);
@@ -78,8 +78,10 @@ static void snd_serial_generic_tx_work(struct work_struct *work) 
		if (!test_bit(SERIAL_MODE_OUTPUT_OPEN, &drvdata->filemode))

			break;



		num_bytes = snd_rawmidi_transmit_peek(substream, buf, INTERNAL_BUF_SIZE);

		num_bytes = serdev_device_write_buf(drvdata->serdev, buf, num_bytes);

		num_bytes = snd_rawmidi_transmit_peek(substream, drvdata->tx_buf,

						      INTERNAL_BUF_SIZE);

		num_bytes = serdev_device_write_buf(drvdata->serdev, drvdata->tx_buf,

						    num_bytes);



		if (!num_bytes)

			break;