diff mbox series

[v2,2/4] media: chips-media: wave5: Avoid race condition for interrupt handling

Message ID 20241217045125.58-3-jackson.lee@chipsnmedia.com (mailing list archive)
State New
Headers show
Series Fix critical bugs | expand

Commit Message

jackson.lee Dec. 17, 2024, 4:51 a.m. UTC 
In case of multi instance, interrupts can occur for other instances as
soon as interrupt is cleared. If driver reads the instance_info after
clearing the interrupt, it is not guaranteed that the instance_info is
valid for the current interrupt.

Read the instance_info register for each interrupt before clearing the
interrupt.

Signed-off-by: Jackson.lee <jackson.lee@chipsnmedia.com>
Signed-off-by: Nas Chung <nas.chung@chipsnmedia.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
---
 drivers/media/platform/chips-media/wave5/wave5-vpu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Nicolas Dufresne Dec. 17, 2024, 2:04 p.m. UTC | #1 
Le mardi 17 décembre 2024 à 13:51 +0900, Jackson.lee a écrit :
> In case of multi instance, interrupts can occur for other instances as
> soon as interrupt is cleared. If driver reads the instance_info after
> clearing the interrupt, it is not guaranteed that the instance_info is
> valid for the current interrupt.
> 
> Read the instance_info register for each interrupt before clearing the
> interrupt.
> 
> Signed-off-by: Jackson.lee <jackson.lee@chipsnmedia.com>
> Signed-off-by: Nas Chung <nas.chung@chipsnmedia.com>
> Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>

Same, what is the Fixes tag ?

> ---
>  drivers/media/platform/chips-media/wave5/wave5-vpu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu.c b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> index 6b294a2d6717..63a607d10433 100644
> --- a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> +++ b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> @@ -55,12 +55,12 @@ static void wave5_vpu_handle_irq(void *dev_id)
>  	struct vpu_device *dev = dev_id;
>  
>  	irq_reason = wave5_vdi_read_register(dev, W5_VPU_VINT_REASON);
> +	seq_done = wave5_vdi_read_register(dev, W5_RET_SEQ_DONE_INSTANCE_INFO);
> +	cmd_done = wave5_vdi_read_register(dev, W5_RET_QUEUE_CMD_DONE_INST);
>  	wave5_vdi_write_register(dev, W5_VPU_VINT_REASON_CLR, irq_reason);
>  	wave5_vdi_write_register(dev, W5_VPU_VINT_CLEAR, 0x1);
>  
>  	list_for_each_entry(inst, &dev->instances, list) {
> -		seq_done = wave5_vdi_read_register(dev, W5_RET_SEQ_DONE_INSTANCE_INFO);
> -		cmd_done = wave5_vdi_read_register(dev, W5_RET_QUEUE_CMD_DONE_INST);
>  
>  		if (irq_reason & BIT(INT_WAVE5_INIT_SEQ) ||
>  		    irq_reason & BIT(INT_WAVE5_ENC_SET_PARAM)) {
jackson.lee Dec. 18, 2024, 3:02 a.m. UTC | #2 
Hi Nicolas


> -----Original Message-----
> From: Nicolas Dufresne <nicolas.dufresne@collabora.com>
> Sent: Tuesday, December 17, 2024 11:04 PM
> To: jackson.lee <jackson.lee@chipsnmedia.com>; mchehab@kernel.org;
> hverkuil-cisco@xs4all.nl; sebastian.fricke@collabora.com;
> bob.beckett@collabora.com; dafna.hirschfeld@collabora.com
> Cc: linux-media@vger.kernel.org; linux-kernel@vger.kernel.org; lafley.kim
> <lafley.kim@chipsnmedia.com>; b-brnich@ti.com; hverkuil@xs4all.nl; Nas
> Chung <nas.chung@chipsnmedia.com>
> Subject: Re: [PATCH v2 2/4] media: chips-media: wave5: Avoid race
> condition for interrupt handling
> 
> Le mardi 17 décembre 2024 à 13:51 +0900, Jackson.lee a écrit :
> > In case of multi instance, interrupts can occur for other instances as
> > soon as interrupt is cleared. If driver reads the instance_info after
> > clearing the interrupt, it is not guaranteed that the instance_info is
> > valid for the current interrupt.
> >
> > Read the instance_info register for each interrupt before clearing the
> > interrupt.
> >
> > Signed-off-by: Jackson.lee <jackson.lee@chipsnmedia.com>
> > Signed-off-by: Nas Chung <nas.chung@chipsnmedia.com>
> > Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
> 
> Same, what is the Fixes tag ?


Fixes: ed7276ed2fd0 ("media: chips-media: wave5: Add hrtimer based polling support")

thanks


> 
> > ---
> >  drivers/media/platform/chips-media/wave5/wave5-vpu.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> > b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> > index 6b294a2d6717..63a607d10433 100644
> > --- a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> > +++ b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
> > @@ -55,12 +55,12 @@ static void wave5_vpu_handle_irq(void *dev_id)
> >  	struct vpu_device *dev = dev_id;
> >
> >  	irq_reason = wave5_vdi_read_register(dev, W5_VPU_VINT_REASON);
> > +	seq_done = wave5_vdi_read_register(dev,
> W5_RET_SEQ_DONE_INSTANCE_INFO);
> > +	cmd_done = wave5_vdi_read_register(dev, W5_RET_QUEUE_CMD_DONE_INST);
> >  	wave5_vdi_write_register(dev, W5_VPU_VINT_REASON_CLR, irq_reason);
> >  	wave5_vdi_write_register(dev, W5_VPU_VINT_CLEAR, 0x1);
> >
> >  	list_for_each_entry(inst, &dev->instances, list) {
> > -		seq_done = wave5_vdi_read_register(dev,
> W5_RET_SEQ_DONE_INSTANCE_INFO);
> > -		cmd_done = wave5_vdi_read_register(dev,
> W5_RET_QUEUE_CMD_DONE_INST);
> >
> >  		if (irq_reason & BIT(INT_WAVE5_INIT_SEQ) ||
> >  		    irq_reason & BIT(INT_WAVE5_ENC_SET_PARAM)) {
diff mbox series

Patch

diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu.c b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
index 6b294a2d6717..63a607d10433 100644
--- a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
+++ b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
@@ -55,12 +55,12 @@  static void wave5_vpu_handle_irq(void *dev_id)
 	struct vpu_device *dev = dev_id;
 
 	irq_reason = wave5_vdi_read_register(dev, W5_VPU_VINT_REASON);
+	seq_done = wave5_vdi_read_register(dev, W5_RET_SEQ_DONE_INSTANCE_INFO);
+	cmd_done = wave5_vdi_read_register(dev, W5_RET_QUEUE_CMD_DONE_INST);
 	wave5_vdi_write_register(dev, W5_VPU_VINT_REASON_CLR, irq_reason);
 	wave5_vdi_write_register(dev, W5_VPU_VINT_CLEAR, 0x1);
 
 	list_for_each_entry(inst, &dev->instances, list) {
-		seq_done = wave5_vdi_read_register(dev, W5_RET_SEQ_DONE_INSTANCE_INFO);
-		cmd_done = wave5_vdi_read_register(dev, W5_RET_QUEUE_CMD_DONE_INST);
 
 		if (irq_reason & BIT(INT_WAVE5_INIT_SEQ) ||
 		    irq_reason & BIT(INT_WAVE5_ENC_SET_PARAM)) {