summaryrefslogtreecommitdiff
path: root/sound/usb/usx2y/usb_stream.h
blob: 90369001eab6612ba4cd1a0a774387042ccfd462 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
#ifndef __USB_STREAM_H
#define __USB_STREAM_H

#include <uapi/sound/usb_stream.h>

#define USB_STREAM_NURBS 4
#define USB_STREAM_URBDEPTH 4

struct usb_stream_kernel {
	struct usb_stream *s;

	void *write_page;

	unsigned n_o_ps;

	struct urb *inurb[USB_STREAM_NURBS];
	struct urb *idle_inurb;
	struct urb *completed_inurb;
	struct urb *outurb[USB_STREAM_NURBS];
	struct urb *idle_outurb;
	struct urb *completed_outurb;
	struct urb *i_urb;

	int iso_frame_balance;

	wait_queue_head_t sleep;

	unsigned out_phase;
	unsigned out_phase_peeked;
	unsigned freqn;
};

struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
				  struct usb_device *dev,
				  unsigned in_endpoint, unsigned out_endpoint,
				  unsigned sample_rate, unsigned use_packsize,
				  unsigned period_frames, unsigned frame_size);
void usb_stream_free(struct usb_stream_kernel *);
int usb_stream_start(struct usb_stream_kernel *);
void usb_stream_stop(struct usb_stream_kernel *);

#endif /* __USB_STREAM_H */
6323c675a44cb1a1f9dbd'>diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'tools/perf/arch/powerpc/util')