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From: Tomasz Figa <tfiga@chromium.org>
To: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Cc: mchehab@kernel.org, dafna3@gmail.com, hverkuil@xs4all.nl,
	linux-rockchip@lists.infradead.org, helen.koike@collabora.com,
	laurent.pinchart@ideasonboard.com, sakari.ailus@linux.intel.com,
	kernel@collabora.com, ezequiel@collabora.com,
	linux-media@vger.kernel.org
Subject: Re: [PATCH v3 01/12] media: staging: rkisp1: params: upon stream stop, iterate a local list to return the buffers
Date: Fri, 25 Sep 2020 19:08:23 +0000	[thread overview]
Message-ID: <20200925190823.GE3607091@chromium.org> (raw)
In-Reply-To: <20200922113402.12442-2-dafna.hirschfeld@collabora.com>

Hi Dafna,

On Tue, Sep 22, 2020 at 01:33:51PM +0200, Dafna Hirschfeld wrote:
> The code in '.stop_streaming' callback releases and acquire the lock
> at each iteration when returning the buffers.
> Holding the lock disables interrupts so it should be minimized.
> To make the code cleaner and still minimize holding the lock,
> the buffer list is first moved to a local list and
> then can be iterated without the lock.
> 
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
> Acked-by: Helen Koike <helen.koike@collabora.com>
> ---
>  drivers/staging/media/rkisp1/rkisp1-params.c | 31 +++++++-------------
>  1 file changed, 11 insertions(+), 20 deletions(-)
> 

Thank you for the patch. Please see my comments inline.

> diff --git a/drivers/staging/media/rkisp1/rkisp1-params.c b/drivers/staging/media/rkisp1/rkisp1-params.c
> index 3ca2afc51ead..85f3b340c3bf 100644
> --- a/drivers/staging/media/rkisp1/rkisp1-params.c
> +++ b/drivers/staging/media/rkisp1/rkisp1-params.c
> @@ -1469,32 +1469,23 @@ static void rkisp1_params_vb2_stop_streaming(struct vb2_queue *vq)
>  {
>  	struct rkisp1_params *params = vq->drv_priv;
>  	struct rkisp1_buffer *buf;
> +	struct list_head tmp_list;
>  	unsigned long flags;
> -	unsigned int i;
>  
> -	/* stop params input firstly */
> +	INIT_LIST_HEAD(&tmp_list);

nit: This could be done at declaration time by using the LIST_HEAD()
macro to declare the list head.

> +
> +	/*
> +	 * we first move the buffers into a local list 'tmp_list'
> +	 * and then we can iterate it and call vb2_buffer_done
> +	 * without holding the lock
> +	 */
>  	spin_lock_irqsave(&params->config_lock, flags);
>  	params->is_streaming = false;
> +	list_cut_position(&tmp_list, &params->params, params->params.prev);

nit: This is equivalent to list_splice_init(&params->params, &tmp_list);
with a simpler interface and without the need to dereference
params->params.prev manually.

Best regards,
Tomasz

_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip

WARNING: multiple messages have this Message-ID (diff)
From: Tomasz Figa <tfiga@chromium.org>
To: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Cc: linux-media@vger.kernel.org, laurent.pinchart@ideasonboard.com,
	helen.koike@collabora.com, ezequiel@collabora.com,
	hverkuil@xs4all.nl, kernel@collabora.com, dafna3@gmail.com,
	sakari.ailus@linux.intel.com, linux-rockchip@lists.infradead.org,
	mchehab@kernel.org
Subject: Re: [PATCH v3 01/12] media: staging: rkisp1: params: upon stream stop, iterate a local list to return the buffers
Date: Fri, 25 Sep 2020 19:08:23 +0000	[thread overview]
Message-ID: <20200925190823.GE3607091@chromium.org> (raw)
In-Reply-To: <20200922113402.12442-2-dafna.hirschfeld@collabora.com>

Hi Dafna,

On Tue, Sep 22, 2020 at 01:33:51PM +0200, Dafna Hirschfeld wrote:
> The code in '.stop_streaming' callback releases and acquire the lock
> at each iteration when returning the buffers.
> Holding the lock disables interrupts so it should be minimized.
> To make the code cleaner and still minimize holding the lock,
> the buffer list is first moved to a local list and
> then can be iterated without the lock.
> 
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
> Acked-by: Helen Koike <helen.koike@collabora.com>
> ---
>  drivers/staging/media/rkisp1/rkisp1-params.c | 31 +++++++-------------
>  1 file changed, 11 insertions(+), 20 deletions(-)
> 

Thank you for the patch. Please see my comments inline.

> diff --git a/drivers/staging/media/rkisp1/rkisp1-params.c b/drivers/staging/media/rkisp1/rkisp1-params.c
> index 3ca2afc51ead..85f3b340c3bf 100644
> --- a/drivers/staging/media/rkisp1/rkisp1-params.c
> +++ b/drivers/staging/media/rkisp1/rkisp1-params.c
> @@ -1469,32 +1469,23 @@ static void rkisp1_params_vb2_stop_streaming(struct vb2_queue *vq)
>  {
>  	struct rkisp1_params *params = vq->drv_priv;
>  	struct rkisp1_buffer *buf;
> +	struct list_head tmp_list;
>  	unsigned long flags;
> -	unsigned int i;
>  
> -	/* stop params input firstly */
> +	INIT_LIST_HEAD(&tmp_list);

nit: This could be done at declaration time by using the LIST_HEAD()
macro to declare the list head.

> +
> +	/*
> +	 * we first move the buffers into a local list 'tmp_list'
> +	 * and then we can iterate it and call vb2_buffer_done
> +	 * without holding the lock
> +	 */
>  	spin_lock_irqsave(&params->config_lock, flags);
>  	params->is_streaming = false;
> +	list_cut_position(&tmp_list, &params->params, params->params.prev);

nit: This is equivalent to list_splice_init(&params->params, &tmp_list);
with a simpler interface and without the need to dereference
params->params.prev manually.

Best regards,
Tomasz

  reply	other threads:[~2020-09-25 19:08 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-22 11:33 [PATCH v3 00/12] media: staging: rkisp1: various bug fixes Dafna Hirschfeld
2020-09-22 11:33 ` Dafna Hirschfeld
2020-09-22 11:33 ` [PATCH v3 01/12] media: staging: rkisp1: params: upon stream stop, iterate a local list to return the buffers Dafna Hirschfeld
2020-09-22 11:33   ` Dafna Hirschfeld
2020-09-25 19:08   ` Tomasz Figa [this message]
2020-09-25 19:08     ` Tomasz Figa
2020-09-22 11:33 ` [PATCH v3 02/12] media: staging: rkisp1: params: in the isr, return if buffer list is empty Dafna Hirschfeld
2020-09-22 11:33   ` Dafna Hirschfeld
2020-09-22 11:33 ` [PATCH v3 03/12] media: staging: rkisp1: params: use the new effect value in cproc config Dafna Hirschfeld
2020-09-22 11:33   ` Dafna Hirschfeld
2020-09-22 11:33 ` [PATCH v3 04/12] media: staging: rkisp1: params: avoid using buffer if params is not streaming Dafna Hirschfeld
2020-09-22 11:33   ` Dafna Hirschfeld
2020-09-25 20:16   ` Tomasz Figa
2020-09-25 20:16     ` Tomasz Figa
2020-09-22 11:33 ` [PATCH v3 05/12] media: staging: rkisp1: params: set vb.sequence to be the isp's frame_sequence + 1 Dafna Hirschfeld
2020-09-22 11:33   ` Dafna Hirschfeld
2020-09-22 11:33 ` [PATCH v3 06/12] media: staging: rkisp1: remove atomic operations for frame sequence Dafna Hirschfeld
2020-09-22 11:33   ` Dafna Hirschfeld
2020-09-25 20:42   ` Tomasz Figa
2020-09-25 20:42     ` Tomasz Figa
2020-10-02  9:16     ` Dafna Hirschfeld
2020-10-02  9:16       ` Dafna Hirschfeld
2020-10-02 15:30       ` Tomasz Figa
2020-10-02 15:30         ` Tomasz Figa
2020-11-06 14:43         ` Helen Koike
2020-11-06 14:43           ` Helen Koike
2020-11-10 10:40           ` Tomasz Figa
2020-11-10 10:40             ` Tomasz Figa
2020-09-22 11:33 ` [PATCH v3 07/12] media: staging: rkisp1: isp: add a warning and debugfs var for irq delay Dafna Hirschfeld
2020-09-22 11:33   ` Dafna Hirschfeld
2020-09-22 11:33 ` [PATCH v3 08/12] media: staging: rkisp1: isp: don't enable signal RKISP1_CIF_ISP_FRAME_IN Dafna Hirschfeld
2020-09-22 11:33   ` Dafna Hirschfeld
2020-09-22 11:33 ` [PATCH v3 09/12] media: staging: rkisp1: stats: protect write to 'is_streaming' in start_streaming cb Dafna Hirschfeld
2020-09-22 11:33   ` Dafna Hirschfeld
2020-09-25 20:47   ` Tomasz Figa
2020-09-25 20:47     ` Tomasz Figa
2020-09-22 11:34 ` [PATCH v3 10/12] media: staging: rkisp1: params: no need to lock default config Dafna Hirschfeld
2020-09-22 11:34   ` Dafna Hirschfeld
2020-09-22 11:34 ` [PATCH v3 11/12] media: staging: rkisp1: use the right variants of spin_lock Dafna Hirschfeld
2020-09-22 11:34   ` Dafna Hirschfeld
2020-09-25 20:51   ` Tomasz Figa
2020-09-25 20:51     ` Tomasz Figa
2020-09-22 11:34 ` [PATCH v3 12/12] media: staging: rkisp1: cap: protect access to buf with the spin lock Dafna Hirschfeld
2020-09-22 11:34   ` Dafna Hirschfeld
2020-09-25 20:53   ` Tomasz Figa
2020-09-25 20:53     ` Tomasz Figa
2020-09-27  9:43   ` Mauro Carvalho Chehab
2020-09-27  9:43     ` Mauro Carvalho Chehab
2020-09-27  9:54     ` Dafna Hirschfeld
2020-09-27  9:54       ` Dafna Hirschfeld
2020-09-27 11:05       ` Mauro Carvalho Chehab
2020-09-27 11:05         ` Mauro Carvalho Chehab
2020-09-28 15:29         ` Dafna Hirschfeld
2020-09-28 15:29           ` Dafna Hirschfeld

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