media video cx23888 driver: ported to new kfifo API
Fix the cx23888 driver to use the new kfifo API. Using kfifo_reset()
may result in a possible race conditions. This patch fixes it by using
a spinlock around the kfifo_reset() function.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Reviewed-by: Andy Walls <awalls@radix.net>
Acked-by: Andy Walls <awalls@radix.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/media/video/cx23885/cx23888-ir.c b/drivers/media/video/cx23885/cx23888-ir.c
index 3ccc8af..2bf57a4 100644
--- a/drivers/media/video/cx23885/cx23888-ir.c
+++ b/drivers/media/video/cx23885/cx23888-ir.c
@@ -124,15 +124,12 @@
atomic_t rxclk_divider;
atomic_t rx_invert;
- struct kfifo *rx_kfifo;
+ struct kfifo rx_kfifo;
spinlock_t rx_kfifo_lock;
struct v4l2_subdev_ir_parameters tx_params;
struct mutex tx_params_lock;
atomic_t txclk_divider;
-
- struct kfifo *tx_kfifo;
- spinlock_t tx_kfifo_lock;
};
static inline struct cx23888_ir_state *to_state(struct v4l2_subdev *sd)
@@ -522,6 +519,7 @@
{
struct cx23888_ir_state *state = to_state(sd);
struct cx23885_dev *dev = state->dev;
+ unsigned long flags;
u32 cntrl = cx23888_ir_read4(dev, CX23888_IR_CNTRL_REG);
u32 irqen = cx23888_ir_read4(dev, CX23888_IR_IRQEN_REG);
@@ -594,8 +592,9 @@
if (i == 0)
break;
j = i * sizeof(u32);
- k = kfifo_put(state->rx_kfifo,
- (unsigned char *) rx_data, j);
+ k = kfifo_in_locked(&state->rx_kfifo,
+ (unsigned char *) rx_data, j,
+ &state->rx_kfifo_lock);
if (k != j)
kror++; /* rx_kfifo over run */
}
@@ -631,8 +630,11 @@
cx23888_ir_write4(dev, CX23888_IR_CNTRL_REG, cntrl);
*handled = true;
}
- if (kfifo_len(state->rx_kfifo) >= CX23888_IR_RX_KFIFO_SIZE / 2)
+
+ spin_lock_irqsave(&state->rx_kfifo_lock, flags);
+ if (kfifo_len(&state->rx_kfifo) >= CX23888_IR_RX_KFIFO_SIZE / 2)
events |= V4L2_SUBDEV_IR_RX_FIFO_SERVICE_REQ;
+ spin_unlock_irqrestore(&state->rx_kfifo_lock, flags);
if (events)
v4l2_subdev_notify(sd, V4L2_SUBDEV_IR_RX_NOTIFY, &events);
@@ -657,7 +659,7 @@
return 0;
}
- n = kfifo_get(state->rx_kfifo, buf, n);
+ n = kfifo_out_locked(&state->rx_kfifo, buf, n, &state->rx_kfifo_lock);
n /= sizeof(u32);
*num = n * sizeof(u32);
@@ -785,7 +787,12 @@
o->interrupt_enable = p->interrupt_enable;
o->enable = p->enable;
if (p->enable) {
- kfifo_reset(state->rx_kfifo);
+ unsigned long flags;
+
+ spin_lock_irqsave(&state->rx_kfifo_lock, flags);
+ kfifo_reset(&state->rx_kfifo);
+ /* reset tx_fifo too if there is one... */
+ spin_unlock_irqrestore(&state->rx_kfifo_lock, flags);
if (p->interrupt_enable)
irqenable_rx(dev, IRQEN_RSE | IRQEN_RTE | IRQEN_ROE);
control_rx_enable(dev, p->enable);
@@ -892,7 +899,6 @@
o->interrupt_enable = p->interrupt_enable;
o->enable = p->enable;
if (p->enable) {
- kfifo_reset(state->tx_kfifo);
if (p->interrupt_enable)
irqenable_tx(dev, IRQEN_TSE);
control_tx_enable(dev, p->enable);
@@ -1168,19 +1174,9 @@
return -ENOMEM;
spin_lock_init(&state->rx_kfifo_lock);
- state->rx_kfifo = kfifo_alloc(CX23888_IR_RX_KFIFO_SIZE, GFP_KERNEL,
- &state->rx_kfifo_lock);
- if (state->rx_kfifo == NULL)
+ if (kfifo_alloc(&state->rx_kfifo, CX23888_IR_RX_KFIFO_SIZE, GFP_KERNEL))
return -ENOMEM;
- spin_lock_init(&state->tx_kfifo_lock);
- state->tx_kfifo = kfifo_alloc(CX23888_IR_TX_KFIFO_SIZE, GFP_KERNEL,
- &state->tx_kfifo_lock);
- if (state->tx_kfifo == NULL) {
- kfifo_free(state->rx_kfifo);
- return -ENOMEM;
- }
-
state->dev = dev;
state->id = V4L2_IDENT_CX23888_IR;
state->rev = 0;
@@ -1211,8 +1207,7 @@
sizeof(struct v4l2_subdev_ir_parameters));
v4l2_subdev_call(sd, ir, tx_s_parameters, &default_params);
} else {
- kfifo_free(state->rx_kfifo);
- kfifo_free(state->tx_kfifo);
+ kfifo_free(&state->rx_kfifo);
}
return ret;
}
@@ -1231,8 +1226,7 @@
state = to_state(sd);
v4l2_device_unregister_subdev(sd);
- kfifo_free(state->rx_kfifo);
- kfifo_free(state->tx_kfifo);
+ kfifo_free(&state->rx_kfifo);
kfree(state);
/* Nothing more to free() as state held the actual v4l2_subdev object */
return 0;