[alsa-devel] [PATCH] ASoC: intel: Replace kthread with work

Vinod Koul vinod.koul at intel.com
Mon Nov 28 16:52:36 CET 2016


On Mon, Nov 28, 2016 at 04:32:19PM +0100, Takashi Iwai wrote:
> The usage pattern of kthread worker in Intel SST drivers can be
> replaced gracefully with the normal workqueue, which is more light-
> weight and easier to manage in general.  Let's do it.
> 
> While in the replacement, move the schedule_work() call inside the
> spinlock for excluding the race, too.
> 
> Signed-off-by: Takashi Iwai <tiwai at suse.de>
> ---
> 
> Vinod, I tested this only lightly, so it'd be helpful if the patch is
> checked on the affected devices before merging.

We had  apatch done last week internally for this, but this one is fine too.

I will get it verfied on SKL tomorrow and get back

Thanks

> 
>  sound/soc/intel/baytrail/sst-baytrail-ipc.c |  3 +-
>  sound/soc/intel/common/sst-ipc.c            | 58 ++++++++++-------------------
>  sound/soc/intel/common/sst-ipc.h            |  4 +-
>  sound/soc/intel/haswell/sst-haswell-ipc.c   |  3 +-
>  sound/soc/intel/skylake/skl-sst-cldma.c     |  1 -
>  sound/soc/intel/skylake/skl-sst-ipc.c       |  2 +-
>  sound/soc/intel/skylake/skl-sst-ipc.h       |  1 -
>  7 files changed, 24 insertions(+), 48 deletions(-)
> 
> diff --git a/sound/soc/intel/baytrail/sst-baytrail-ipc.c b/sound/soc/intel/baytrail/sst-baytrail-ipc.c
> index 7ab14ce65a73..260447da32b8 100644
> --- a/sound/soc/intel/baytrail/sst-baytrail-ipc.c
> +++ b/sound/soc/intel/baytrail/sst-baytrail-ipc.c
> @@ -23,7 +23,6 @@
>  #include <linux/slab.h>
>  #include <linux/delay.h>
>  #include <linux/platform_device.h>
> -#include <linux/kthread.h>
>  #include <linux/firmware.h>
>  #include <linux/io.h>
>  #include <asm/div64.h>
> @@ -338,7 +337,7 @@ static irqreturn_t sst_byt_irq_thread(int irq, void *context)
>  	spin_unlock_irqrestore(&sst->spinlock, flags);
>  
>  	/* continue to send any remaining messages... */
> -	kthread_queue_work(&ipc->kworker, &ipc->kwork);
> +	schedule_work(&ipc->kwork);
>  
>  	return IRQ_HANDLED;
>  }
> diff --git a/sound/soc/intel/common/sst-ipc.c b/sound/soc/intel/common/sst-ipc.c
> index 6c672ac79cce..d20356255d0c 100644
> --- a/sound/soc/intel/common/sst-ipc.c
> +++ b/sound/soc/intel/common/sst-ipc.c
> @@ -26,7 +26,6 @@
>  #include <linux/sched.h>
>  #include <linux/delay.h>
>  #include <linux/platform_device.h>
> -#include <linux/kthread.h>
>  #include <sound/asound.h>
>  
>  #include "sst-dsp.h"
> @@ -109,10 +108,9 @@ static int ipc_tx_message(struct sst_generic_ipc *ipc, u64 header,
>  		ipc->ops.tx_data_copy(msg, tx_data, tx_bytes);
>  
>  	list_add_tail(&msg->list, &ipc->tx_list);
> +	schedule_work(&ipc->kwork);
>  	spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
>  
> -	kthread_queue_work(&ipc->kworker, &ipc->kwork);
> -
>  	if (wait)
>  		return tx_wait_done(ipc, msg, rx_data);
>  	else
> @@ -156,35 +154,32 @@ static int msg_empty_list_init(struct sst_generic_ipc *ipc)
>  	return -ENOMEM;
>  }
>  
> -static void ipc_tx_msgs(struct kthread_work *work)
> +static void ipc_tx_msgs(struct work_struct *work)
>  {
>  	struct sst_generic_ipc *ipc =
>  		container_of(work, struct sst_generic_ipc, kwork);
>  	struct ipc_message *msg;
> -	unsigned long flags;
>  
> -	spin_lock_irqsave(&ipc->dsp->spinlock, flags);
> +	spin_lock_irq(&ipc->dsp->spinlock);
>  
> -	if (list_empty(&ipc->tx_list) || ipc->pending) {
> -		spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
> -		return;
> -	}
> -
> -	/* if the DSP is busy, we will TX messages after IRQ.
> -	 * also postpone if we are in the middle of procesing completion irq*/
> -	if (ipc->ops.is_dsp_busy && ipc->ops.is_dsp_busy(ipc->dsp)) {
> -		dev_dbg(ipc->dev, "ipc_tx_msgs dsp busy\n");
> -		spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
> -		return;
> -	}
> +	while (!list_empty(&ipc->tx_list) && !ipc->pending) {
> +		/* if the DSP is busy, we will TX messages after IRQ.
> +		 * also postpone if we are in the middle of processing
> +		 * completion irq
> +		 */
> +		if (ipc->ops.is_dsp_busy && ipc->ops.is_dsp_busy(ipc->dsp)) {
> +			dev_dbg(ipc->dev, "ipc_tx_msgs dsp busy\n");
> +			break;
> +		}
>  
> -	msg = list_first_entry(&ipc->tx_list, struct ipc_message, list);
> -	list_move(&msg->list, &ipc->rx_list);
> +		msg = list_first_entry(&ipc->tx_list, struct ipc_message, list);
> +		list_move(&msg->list, &ipc->rx_list);
>  
> -	if (ipc->ops.tx_msg != NULL)
> -		ipc->ops.tx_msg(ipc, msg);
> +		if (ipc->ops.tx_msg != NULL)
> +			ipc->ops.tx_msg(ipc, msg);
> +	}
>  
> -	spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
> +	spin_unlock_irq(&ipc->dsp->spinlock);
>  }
>  
>  int sst_ipc_tx_message_wait(struct sst_generic_ipc *ipc, u64 header,
> @@ -280,19 +275,7 @@ int sst_ipc_init(struct sst_generic_ipc *ipc)
>  	if (ret < 0)
>  		return -ENOMEM;
>  
> -	/* start the IPC message thread */
> -	kthread_init_worker(&ipc->kworker);
> -	ipc->tx_thread = kthread_run(kthread_worker_fn,
> -					&ipc->kworker, "%s",
> -					dev_name(ipc->dev));
> -	if (IS_ERR(ipc->tx_thread)) {
> -		dev_err(ipc->dev, "error: failed to create message TX task\n");
> -		ret = PTR_ERR(ipc->tx_thread);
> -		kfree(ipc->msg);
> -		return ret;
> -	}
> -
> -	kthread_init_work(&ipc->kwork, ipc_tx_msgs);
> +	INIT_WORK(&ipc->kwork, ipc_tx_msgs);
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(sst_ipc_init);
> @@ -301,8 +284,7 @@ void sst_ipc_fini(struct sst_generic_ipc *ipc)
>  {
>  	int i;
>  
> -	if (ipc->tx_thread)
> -		kthread_stop(ipc->tx_thread);
> +	cancel_work_sync(&ipc->kwork);
>  
>  	if (ipc->msg) {
>  		for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
> diff --git a/sound/soc/intel/common/sst-ipc.h b/sound/soc/intel/common/sst-ipc.h
> index ceb7e468a3fa..ea79cff5c6cc 100644
> --- a/sound/soc/intel/common/sst-ipc.h
> +++ b/sound/soc/intel/common/sst-ipc.h
> @@ -23,7 +23,6 @@
>  #include <linux/list.h>
>  #include <linux/workqueue.h>
>  #include <linux/sched.h>
> -#include <linux/kthread.h>
>  
>  #define IPC_MAX_MAILBOX_BYTES	256
>  
> @@ -65,8 +64,7 @@ struct sst_generic_ipc {
>  	struct list_head empty_list;
>  	wait_queue_head_t wait_txq;
>  	struct task_struct *tx_thread;
> -	struct kthread_worker kworker;
> -	struct kthread_work kwork;
> +	struct work_struct kwork;
>  	bool pending;
>  	struct ipc_message *msg;
>  	int tx_data_max_size;
> diff --git a/sound/soc/intel/haswell/sst-haswell-ipc.c b/sound/soc/intel/haswell/sst-haswell-ipc.c
> index e432a31fd9f2..a3459d1682a6 100644
> --- a/sound/soc/intel/haswell/sst-haswell-ipc.c
> +++ b/sound/soc/intel/haswell/sst-haswell-ipc.c
> @@ -26,7 +26,6 @@
>  #include <linux/delay.h>
>  #include <linux/sched.h>
>  #include <linux/platform_device.h>
> -#include <linux/kthread.h>
>  #include <linux/firmware.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/debugfs.h>
> @@ -818,7 +817,7 @@ static irqreturn_t hsw_irq_thread(int irq, void *context)
>  	spin_unlock_irqrestore(&sst->spinlock, flags);
>  
>  	/* continue to send any remaining messages... */
> -	kthread_queue_work(&ipc->kworker, &ipc->kwork);
> +	schedule_work(&ipc->kwork);
>  
>  	return IRQ_HANDLED;
>  }
> diff --git a/sound/soc/intel/skylake/skl-sst-cldma.c b/sound/soc/intel/skylake/skl-sst-cldma.c
> index efa2532114ba..c9f6d87381db 100644
> --- a/sound/soc/intel/skylake/skl-sst-cldma.c
> +++ b/sound/soc/intel/skylake/skl-sst-cldma.c
> @@ -17,7 +17,6 @@
>  
>  #include <linux/device.h>
>  #include <linux/mm.h>
> -#include <linux/kthread.h>
>  #include <linux/delay.h>
>  #include "../common/sst-dsp.h"
>  #include "../common/sst-dsp-priv.h"
> diff --git a/sound/soc/intel/skylake/skl-sst-ipc.c b/sound/soc/intel/skylake/skl-sst-ipc.c
> index 797cf4053235..499c0b15e5d0 100644
> --- a/sound/soc/intel/skylake/skl-sst-ipc.c
> +++ b/sound/soc/intel/skylake/skl-sst-ipc.c
> @@ -464,7 +464,7 @@ irqreturn_t skl_dsp_irq_thread_handler(int irq, void *context)
>  	skl_ipc_int_enable(dsp);
>  
>  	/* continue to send any remaining messages... */
> -	kthread_queue_work(&ipc->kworker, &ipc->kwork);
> +	schedule_work(&ipc->kwork);
>  
>  	return IRQ_HANDLED;
>  }
> diff --git a/sound/soc/intel/skylake/skl-sst-ipc.h b/sound/soc/intel/skylake/skl-sst-ipc.h
> index 0334ed4af031..5c37442a6db4 100644
> --- a/sound/soc/intel/skylake/skl-sst-ipc.h
> +++ b/sound/soc/intel/skylake/skl-sst-ipc.h
> @@ -16,7 +16,6 @@
>  #ifndef __SKL_IPC_H
>  #define __SKL_IPC_H
>  
> -#include <linux/kthread.h>
>  #include <linux/irqreturn.h>
>  #include "../common/sst-ipc.h"
>  
> -- 
> 2.10.2
> 

-- 
~Vinod


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