* [patch] media video cx23888 driver: fix possible races using new kfifo_API kfifo_reset()
@ 2009-12-18 22:21 Stefani Seibold
2009-12-18 23:43 ` Andy Walls
0 siblings, 1 reply; 3+ messages in thread
From: Stefani Seibold @ 2009-12-18 22:21 UTC (permalink / raw)
To: linux-kernel, Andrew Morton, Mauro Carvalho Chehab, Andy Walls,
Linux Media Mailing List
Fix the cx23888 driver to use the new kfifo API. Using kfifo_reset() may
result in a possible race conditions. This patch fix it by using
spinlock around the kfifo_reset() function.
The patch-set is against mm tree from 11-Dec-2009
Greetings,
Stefani
Signed-off-by: Stefani Seibold <stefani@seibold.net>
---
cx23888-ir.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- mmotm.orig/drivers/media/video/cx23885/cx23888-ir.c 2009-12-18 22:57:13.588337402 +0100
+++ mmotm/drivers/media/video/cx23885/cx23888-ir.c 2009-12-18 23:15:14.651365720 +0100
@@ -519,6 +519,7 @@ static int cx23888_ir_irq_handler(struct
{
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);
@@ -629,8 +630,11 @@ static int cx23888_ir_irq_handler(struct
cx23888_ir_write4(dev, CX23888_IR_CNTRL_REG, cntrl);
*handled = true;
}
+
+ 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);
@@ -783,7 +787,12 @@ static int cx23888_ir_rx_s_parameters(st
o->interrupt_enable = p->interrupt_enable;
o->enable = p->enable;
if (p->enable) {
+ 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);
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [patch] media video cx23888 driver: fix possible races using new kfifo_API kfifo_reset()
2009-12-18 22:21 [patch] media video cx23888 driver: fix possible races using new kfifo_API kfifo_reset() Stefani Seibold
@ 2009-12-18 23:43 ` Andy Walls
2009-12-19 10:15 ` Mauro Carvalho Chehab
0 siblings, 1 reply; 3+ messages in thread
From: Andy Walls @ 2009-12-18 23:43 UTC (permalink / raw)
To: Stefani Seibold
Cc: linux-kernel, Andrew Morton, Mauro Carvalho Chehab,
Linux Media Mailing List
On Fri, 2009-12-18 at 23:21 +0100, Stefani Seibold wrote:
> Fix the cx23888 driver to use the new kfifo API. Using kfifo_reset() may
> result in a possible race conditions. This patch fix it by using
> spinlock around the kfifo_reset() function.
>
> The patch-set is against mm tree from 11-Dec-2009
>
> Greetings,
> Stefani
>
> Signed-off-by: Stefani Seibold <stefani@seibold.net>
For both this patch together with your previous patch:
Reviewed-by: Andy Walls <awalls@radix.net>
Acked-by: Andy Walls <awalls@radix.net>
Thanks Stefani.
Regards,
Andy
> ---
> cx23888-ir.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> --- mmotm.orig/drivers/media/video/cx23885/cx23888-ir.c 2009-12-18 22:57:13.588337402 +0100
> +++ mmotm/drivers/media/video/cx23885/cx23888-ir.c 2009-12-18 23:15:14.651365720 +0100
> @@ -519,6 +519,7 @@ static int cx23888_ir_irq_handler(struct
> {
> 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);
> @@ -629,8 +630,11 @@ static int cx23888_ir_irq_handler(struct
> cx23888_ir_write4(dev, CX23888_IR_CNTRL_REG, cntrl);
> *handled = true;
> }
> +
> + 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);
> @@ -783,7 +787,12 @@ static int cx23888_ir_rx_s_parameters(st
> o->interrupt_enable = p->interrupt_enable;
> o->enable = p->enable;
> if (p->enable) {
> + 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);
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [patch] media video cx23888 driver: fix possible races using new kfifo_API kfifo_reset()
2009-12-18 23:43 ` Andy Walls
@ 2009-12-19 10:15 ` Mauro Carvalho Chehab
0 siblings, 0 replies; 3+ messages in thread
From: Mauro Carvalho Chehab @ 2009-12-19 10:15 UTC (permalink / raw)
To: Andy Walls
Cc: Stefani Seibold, linux-kernel, Andrew Morton, Linux Media Mailing List
Em 18-12-2009 21:43, Andy Walls escreveu:
> On Fri, 2009-12-18 at 23:21 +0100, Stefani Seibold wrote:
>> Fix the cx23888 driver to use the new kfifo API. Using kfifo_reset() may
>> result in a possible race conditions. This patch fix it by using
>> spinlock around the kfifo_reset() function.
>>
>> The patch-set is against mm tree from 11-Dec-2009
>>
>> Greetings,
>> Stefani
>>
>> Signed-off-by: Stefani Seibold <stefani@seibold.net>
>
> For both this patch together with your previous patch:
>
> Reviewed-by: Andy Walls <awalls@radix.net>
> Acked-by: Andy Walls <awalls@radix.net>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
>
> Thanks Stefani.
>
> Regards,
> Andy
>
>> ---
>> cx23888-ir.c | 9 +++++++++
>> 1 file changed, 9 insertions(+)
>>
>> --- mmotm.orig/drivers/media/video/cx23885/cx23888-ir.c 2009-12-18 22:57:13.588337402 +0100
>> +++ mmotm/drivers/media/video/cx23885/cx23888-ir.c 2009-12-18 23:15:14.651365720 +0100
>> @@ -519,6 +519,7 @@ static int cx23888_ir_irq_handler(struct
>> {
>> 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);
>> @@ -629,8 +630,11 @@ static int cx23888_ir_irq_handler(struct
>> cx23888_ir_write4(dev, CX23888_IR_CNTRL_REG, cntrl);
>> *handled = true;
>> }
>> +
>> + 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);
>> @@ -783,7 +787,12 @@ static int cx23888_ir_rx_s_parameters(st
>> o->interrupt_enable = p->interrupt_enable;
>> o->enable = p->enable;
>> if (p->enable) {
>> + 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);
>>
>>
>
> --
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^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2009-12-19 10:16 UTC | newest]
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2009-12-18 22:21 [patch] media video cx23888 driver: fix possible races using new kfifo_API kfifo_reset() Stefani Seibold
2009-12-18 23:43 ` Andy Walls
2009-12-19 10:15 ` Mauro Carvalho Chehab
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