[alsa-devel] [PATCH 1/5] ALSA: dice: split subaddress check from category check

Takashi Iwai tiwai at suse.de
Tue Dec 29 09:54:46 CET 2015


On Sat, 26 Dec 2015 04:35:22 +0100,
Takashi Sakamoto wrote:
> 
> Before allocating an instance of sound card, ALSA dice driver checks
> chip_ID_hi in Bus information block of Config ROM, then also checks
> subaddresses. The former operation reads cache of Config ROM in Linux
> FireWire subsystem, while the latter operation sends read transaction.
> The latter can be merged into initialization of transaction system.
> 
> This commit splits these two operations to reduce needless transactions
> in probe processing.
> 
> Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
> ---
>  sound/firewire/dice/dice-transaction.c | 89 ++++++++++++++++++++++++++--------
>  sound/firewire/dice/dice.c             | 72 +++------------------------
>  2 files changed, 77 insertions(+), 84 deletions(-)
> 
> diff --git a/sound/firewire/dice/dice-transaction.c b/sound/firewire/dice/dice-transaction.c
> index aee7461..75a2125 100644
> --- a/sound/firewire/dice/dice-transaction.c
> +++ b/sound/firewire/dice/dice-transaction.c
> @@ -331,39 +331,59 @@ int snd_dice_transaction_reinit(struct snd_dice *dice)
>  	return register_notification_address(dice, false);
>  }
>  
> -int snd_dice_transaction_init(struct snd_dice *dice)
> +static int get_subaddrs(struct snd_dice *dice)
>  {
> -	struct fw_address_handler *handler = &dice->notification_handler;
> +	static const int min_values[10] = {
> +		10, 0x64 / 4,
> +		10, 0x18 / 4,
> +		10, 0x18 / 4,
> +		0, 0,
> +		0, 0,
> +	};
>  	__be32 *pointers;
> +	u32 data;
> +	unsigned int i;
>  	int err;
>  
> -	/* Use the same way which dice_interface_check() does. */
> -	pointers = kmalloc(sizeof(__be32) * 10, GFP_KERNEL);
> +	pointers = kmalloc_array(ARRAY_SIZE(min_values), sizeof(__be32),
> +				 GFP_KERNEL);
>  	if (pointers == NULL)
>  		return -ENOMEM;
>  
> -	/* Get offsets for sub-addresses */
> +	/*
> +	 * Check that the sub address spaces exist and are located inside the
> +	 * private address space.  The minimum values are chosen so that all
> +	 * minimally required registers are included.
> +	 */
>  	err = snd_fw_transaction(dice->unit, TCODE_READ_BLOCK_REQUEST,
> -				 DICE_PRIVATE_SPACE,
> -				 pointers, sizeof(__be32) * 10, 0);
> +				 DICE_PRIVATE_SPACE, pointers,
> +				 sizeof(__be32) * ARRAY_SIZE(min_values), 0);
>  	if (err < 0)
>  		goto end;
>  
> -	/* Allocation callback in address space over host controller */
> -	handler->length = 4;
> -	handler->address_callback = dice_notification;
> -	handler->callback_data = dice;
> -	err = fw_core_add_address_handler(handler, &fw_high_memory_region);
> -	if (err < 0) {
> -		handler->callback_data = NULL;
> -		goto end;
> +	for (i = 0; i < ARRAY_SIZE(min_values); ++i) {
> +		data = be32_to_cpu(pointers[i]);
> +		if (data < min_values[i] || data >= 0x40000) {
> +			err = -ENODEV;
> +			goto end;
> +		}
>  	}
>  
> -	/* Register the address space */
> -	err = register_notification_address(dice, true);
> -	if (err < 0) {
> -		fw_core_remove_address_handler(handler);
> -		handler->callback_data = NULL;
> +	/*
> +	 * Check that the implemented DICE driver specification major version
> +	 * number matches.
> +	 */
> +	err = snd_fw_transaction(dice->unit, TCODE_READ_QUADLET_REQUEST,
> +				 DICE_PRIVATE_SPACE +
> +				 be32_to_cpu(pointers[0]) * 4 + GLOBAL_VERSION,
> +				 &data, sizeof(data), 0);

It's confusing to reuse a single variable as both u32 and be32.
Use the specific variable like the original code instead.


thanks,

Takashi


> +	if (err < 0)
> +		goto end;
> +
> +	if ((data & cpu_to_be32(0xff000000)) != cpu_to_be32(0x01000000)) {
> +		dev_err(&dice->unit->device,
> +			"unknown DICE version: 0x%08x\n", be32_to_cpu(data));
> +		err = -ENODEV;
>  		goto end;
>  	}
>  
> @@ -380,3 +400,32 @@ end:
>  	kfree(pointers);
>  	return err;
>  }
> +
> +int snd_dice_transaction_init(struct snd_dice *dice)
> +{
> +	struct fw_address_handler *handler = &dice->notification_handler;
> +	int err;
> +
> +	err = get_subaddrs(dice);
> +	if (err < 0)
> +		return err;
> +
> +	/* Allocation callback in address space over host controller */
> +	handler->length = 4;
> +	handler->address_callback = dice_notification;
> +	handler->callback_data = dice;
> +	err = fw_core_add_address_handler(handler, &fw_high_memory_region);
> +	if (err < 0) {
> +		handler->callback_data = NULL;
> +		return err;
> +	}
> +
> +	/* Register the address space */
> +	err = register_notification_address(dice, true);
> +	if (err < 0) {
> +		fw_core_remove_address_handler(handler);
> +		handler->callback_data = NULL;
> +	}
> +
> +	return err;
> +}
> diff --git a/sound/firewire/dice/dice.c b/sound/firewire/dice/dice.c
> index 0cda05c..26271cc 100644
> --- a/sound/firewire/dice/dice.c
> +++ b/sound/firewire/dice/dice.c
> @@ -18,27 +18,12 @@ MODULE_LICENSE("GPL v2");
>  #define WEISS_CATEGORY_ID	0x00
>  #define LOUD_CATEGORY_ID	0x10
>  
> -static int dice_interface_check(struct fw_unit *unit)
> +static int check_dice_category(struct fw_unit *unit)
>  {
> -	static const int min_values[10] = {
> -		10, 0x64 / 4,
> -		10, 0x18 / 4,
> -		10, 0x18 / 4,
> -		0, 0,
> -		0, 0,
> -	};
>  	struct fw_device *device = fw_parent_device(unit);
>  	struct fw_csr_iterator it;
> -	int key, val, vendor = -1, model = -1, err;
> -	unsigned int category, i;
> -	__be32 *pointers;
> -	u32 value;
> -	__be32 version;
> -
> -	pointers = kmalloc_array(ARRAY_SIZE(min_values), sizeof(__be32),
> -				 GFP_KERNEL);
> -	if (pointers == NULL)
> -		return -ENOMEM;
> +	int key, val, vendor = -1, model = -1;
> +	unsigned int category;
>  
>  	/*
>  	 * Check that GUID and unit directory are constructed according to DICE
> @@ -64,51 +49,10 @@ static int dice_interface_check(struct fw_unit *unit)
>  	else
>  		category = DICE_CATEGORY_ID;
>  	if (device->config_rom[3] != ((vendor << 8) | category) ||
> -	    device->config_rom[4] >> 22 != model) {
> -		err = -ENODEV;
> -		goto end;
> -	}
> -
> -	/*
> -	 * Check that the sub address spaces exist and are located inside the
> -	 * private address space.  The minimum values are chosen so that all
> -	 * minimally required registers are included.
> -	 */
> -	err = snd_fw_transaction(unit, TCODE_READ_BLOCK_REQUEST,
> -				 DICE_PRIVATE_SPACE, pointers,
> -				 sizeof(__be32) * ARRAY_SIZE(min_values), 0);
> -	if (err < 0) {
> -		err = -ENODEV;
> -		goto end;
> -	}
> -	for (i = 0; i < ARRAY_SIZE(min_values); ++i) {
> -		value = be32_to_cpu(pointers[i]);
> -		if (value < min_values[i] || value >= 0x40000) {
> -			err = -ENODEV;
> -			goto end;
> -		}
> -	}
> +	    device->config_rom[4] >> 22 != model)
> +		return -ENODEV;
>  
> -	/*
> -	 * Check that the implemented DICE driver specification major version
> -	 * number matches.
> -	 */
> -	err = snd_fw_transaction(unit, TCODE_READ_QUADLET_REQUEST,
> -				 DICE_PRIVATE_SPACE +
> -				 be32_to_cpu(pointers[0]) * 4 + GLOBAL_VERSION,
> -				 &version, 4, 0);
> -	if (err < 0) {
> -		err = -ENODEV;
> -		goto end;
> -	}
> -	if ((version & cpu_to_be32(0xff000000)) != cpu_to_be32(0x01000000)) {
> -		dev_err(&unit->device,
> -			"unknown DICE version: 0x%08x\n", be32_to_cpu(version));
> -		err = -ENODEV;
> -		goto end;
> -	}
> -end:
> -	return err;
> +	return 0;
>  }
>  
>  static int highest_supported_mode_rate(struct snd_dice *dice,
> @@ -254,9 +198,9 @@ static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
>  	struct snd_dice *dice;
>  	int err;
>  
> -	err = dice_interface_check(unit);
> +	err = check_dice_category(unit);
>  	if (err < 0)
> -		goto end;
> +		return -ENODEV;
>  
>  	err = snd_card_new(&unit->device, -1, NULL, THIS_MODULE,
>  			   sizeof(*dice), &card);
> -- 
> 2.5.0
> 


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