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/*
 * Linux driver for TerraTec DMX 6Fire USB
 *
 * Author:	Torsten Schenk <torsten.schenk@zoho.com>
 * Created:	Jan 01, 2011
 * Copyright:	(C) Torsten Schenk
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */
#ifndef USB6FIRE_COMM_H
#define USB6FIRE_COMM_H

#include "common.h"

enum /* settings for comm */
{
	COMM_RECEIVER_BUFSIZE = 64,
};

struct comm_runtime {
	struct sfire_chip *chip;

	struct urb receiver;
	u8 *receiver_buffer;

	u8 serial; /* urb serial */

	void (*init_urb)(struct comm_runtime *rt, struct urb *urb, u8 *buffer,
			void *context, void(*handler)(struct urb *urb));
	/* writes control data to the device */
	int (*write8)(struct comm_runtime *rt, u8 request, u8 reg, u8 value);
	int (*write16)(struct comm_runtime *rt, u8 request, u8 reg,
			u8 vh, u8 vl);
};

int usb6fire_comm_init(struct sfire_chip *chip);
void usb6fire_comm_abort(struct sfire_chip *chip);
void usb6fire_comm_destroy(struct sfire_chip *chip);
#endif /* USB6FIRE_COMM_H */

abal.eu/eba/) reported the following double-lock bug: Double lock: 1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236; 2. call to function `pl330_release_channel' immediately after; 3. call to function `dma_pl330_rqcb' in line 1753; 4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505. I have fixed it as suggested by Marek Szyprowski. First, I have replaced `pch->lock' with `pl330->lock' in functions `pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids the double-lock by acquiring a different lock than `dma_pl330_rqcb'. NOTE that, as a result, `pl330_free_chan_resources' executes `list_splice_tail_init' on `pch->work_list' under lock `pl330->lock', whereas in the rest of the code `pch->work_list' is protected by `pch->lock'. I don't know if this may cause race conditions. Similarly `pch->cyclic' is written by `pl330_alloc_chan_resources' under `pl330->lock' but read by `pl330_tx_submit' under `pch->lock'. Second, I have removed locking from `pl330_request_channel' and `pl330_release_channel' functions. Function `pl330_request_channel' is only called from `pl330_alloc_chan_resources', so the lock is already held. Function `pl330_release_channel' is called from `pl330_free_chan_resources', which already holds the lock, and from `pl330_del'. Function `pl330_del' is called in an error path of `pl330_probe' and at the end of `pl330_remove', but I assume that there cannot be concurrent accesses to the protected data at those points. Signed-off-by: Iago Abal <mail@iagoabal.eu> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'sound/usb/bcd2000/Makefile')