Re: [PATCH] staging: speakup: refactor synths array to use a list

[Samuel Thibault]

Hello,

Justin Skists, le lun. 04 juin 2018 10:52:12 +0100, a ecrit:
> The synths[] array is a collection of synths acting like a list.
> There is no need for synths to be an array, so refactor synths[] to use
> standard kernel list_head API, instead, and modify the usages to suit.
> As a side-effect, the maximum number of synths has also become redundant.
> 
> Signed-off-by: Justin Skists <justin.skists@xxxxxxxxxxx>

This needs a review, but the principle looks sound to me :)

Thanks,
Samuel

> ---
>  drivers/staging/speakup/spk_types.h |  2 ++
>  drivers/staging/speakup/synth.c     | 40 ++++++++++-------------------
>  2 files changed, 15 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/staging/speakup/spk_types.h b/drivers/staging/speakup/spk_types.h
> index 3e082dc3d45c..a2fc72c29894 100644
> --- a/drivers/staging/speakup/spk_types.h
> +++ b/drivers/staging/speakup/spk_types.h
> @@ -160,6 +160,8 @@ struct spk_io_ops {
>  };
>  
>  struct spk_synth {
> +	struct list_head node;
> +
>  	const char *name;
>  	const char *version;
>  	const char *long_name;
> diff --git a/drivers/staging/speakup/synth.c b/drivers/staging/speakup/synth.c
> index 7deeb7061018..25f259ee4ffc 100644
> --- a/drivers/staging/speakup/synth.c
> +++ b/drivers/staging/speakup/synth.c
> @@ -18,8 +18,7 @@
>  #include "speakup.h"
>  #include "serialio.h"
>  
> -#define MAXSYNTHS       16      /* Max number of synths in array. */
> -static struct spk_synth *synths[MAXSYNTHS + 1];
> +static LIST_HEAD(synths);
>  struct spk_synth *synth;
>  char spk_pitch_buff[32] = "";
>  static int module_status;
> @@ -355,9 +354,8 @@ struct var_t synth_time_vars[] = {
>  /* called by: speakup_init() */
>  int synth_init(char *synth_name)
>  {
> -	int i;
>  	int ret = 0;
> -	struct spk_synth *synth = NULL;
> +	struct spk_synth *tmp, *synth = NULL;
>  
>  	if (!synth_name)
>  		return 0;
> @@ -371,9 +369,10 @@ int synth_init(char *synth_name)
>  
>  	mutex_lock(&spk_mutex);
>  	/* First, check if we already have it loaded. */
> -	for (i = 0; i < MAXSYNTHS && synths[i]; i++)
> -		if (strcmp(synths[i]->name, synth_name) == 0)
> -			synth = synths[i];
> +	list_for_each_entry(tmp, &synths, node) {
> +		if (strcmp(tmp->name, synth_name) == 0)
> +			synth = tmp;
> +	}
>  
>  	/* If we got one, initialize it now. */
>  	if (synth)
> @@ -448,29 +447,23 @@ void synth_release(void)
>  /* called by: all_driver_init() */
>  int synth_add(struct spk_synth *in_synth)
>  {
> -	int i;
>  	int status = 0;
> +	struct spk_synth *tmp;
>  
>  	mutex_lock(&spk_mutex);
> -	for (i = 0; i < MAXSYNTHS && synths[i]; i++)
> -		/* synth_remove() is responsible for rotating the array down */
> -		if (in_synth == synths[i]) {
> +
> +	list_for_each_entry(tmp, &synths, node) {
> +		if (tmp == in_synth) {
>  			mutex_unlock(&spk_mutex);
>  			return 0;
>  		}
> -	if (i == MAXSYNTHS) {
> -		pr_warn("Error: attempting to add a synth past end of array\n");
> -		mutex_unlock(&spk_mutex);
> -		return -1;
>  	}
>  
>  	if (in_synth->startup)
>  		status = do_synth_init(in_synth);
>  
> -	if (!status) {
> -		synths[i++] = in_synth;
> -		synths[i] = NULL;
> -	}
> +	if (!status)
> +		list_add_tail(&in_synth->node, &synths);
>  
>  	mutex_unlock(&spk_mutex);
>  	return status;
> @@ -479,17 +472,10 @@ EXPORT_SYMBOL_GPL(synth_add);
>  
>  void synth_remove(struct spk_synth *in_synth)
>  {
> -	int i;
> -
>  	mutex_lock(&spk_mutex);
>  	if (synth == in_synth)
>  		synth_release();
> -	for (i = 0; synths[i]; i++) {
> -		if (in_synth == synths[i])
> -			break;
> -	}
> -	for ( ; synths[i]; i++) /* compress table */
> -		synths[i] = synths[i + 1];
> +	list_del(&in_synth->node);
>  	module_status = 0;
>  	mutex_unlock(&spk_mutex);
>  }
> -- 
> 2.17.1
> 
> _______________________________________________
> Speakup mailing list
> Speakup@xxxxxxxxxxxxxxxxx
> http://linux-speakup.org/cgi-bin/mailman/listinfo/speakup

-- 
Samuel
<N> un driver qui fait quoi, alors ?
<y> ben pour les bips
<s> pour passer les oops en morse
 -+- #ens-mim - vive les rapports de bug -+-