Re: [PATCH v2 09/79] ALSA: als300: Allocate resources with device-managed APIs

From: Nathan Chancellor <nathan@kernel.org>
To: Takashi Iwai <tiwai@suse.de>
Cc: alsa-devel@alsa-project.org
Subject: Re: [PATCH v2 09/79] ALSA: als300: Allocate resources with device-managed APIs
Date: Tue, 20 Jul 2021 12:45:17 -0700	[thread overview]
Message-ID: <YPcnzVns1kz7wtxd@Ryzen-9-3900X.localdomain> (raw)
In-Reply-To: <20210715075941.23332-10-tiwai@suse.de>

On Thu, Jul 15, 2021 at 09:58:31AM +0200, Takashi Iwai wrote:
> This patch converts the resource management in PCI als300 driver with
> devres as a clean up.  Each manual resource management is converted
> with the corresponding devres helper, and the card object release is
> managed now via card->private_free instead of a lowlevel snd_device.
> 
> This should give no user-visible functional changes.
> 
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> ---
>  sound/pci/als300.c | 79 ++++++++++------------------------------------
>  1 file changed, 17 insertions(+), 62 deletions(-)
> 
> diff --git a/sound/pci/als300.c b/sound/pci/als300.c
> index 668008fc21f7..9c94072572a5 100644
> --- a/sound/pci/als300.c
> +++ b/sound/pci/als300.c
> @@ -163,21 +163,11 @@ static void snd_als300_set_irq_flag(struct snd_als300 *chip, int cmd)
>  	snd_als300_gcr_write(chip->port, MISC_CONTROL, tmp);
>  }
>  
> -static int snd_als300_free(struct snd_als300 *chip)
> +static void snd_als300_free(struct snd_card *card)
>  {
> -	snd_als300_set_irq_flag(chip, IRQ_DISABLE);
> -	if (chip->irq >= 0)
> -		free_irq(chip->irq, chip);
> -	pci_release_regions(chip->pci);
> -	pci_disable_device(chip->pci);
> -	kfree(chip);
> -	return 0;
> -}
> +	struct snd_als300 *chip = card->private_data;
>  
> -static int snd_als300_dev_free(struct snd_device *device)
> -{
> -	struct snd_als300 *chip = device->device_data;
> -	return snd_als300_free(chip);
> +	snd_als300_set_irq_flag(chip, IRQ_DISABLE);
>  }
>  
>  static irqreturn_t snd_als300_interrupt(int irq, void *dev_id)
> @@ -248,11 +238,6 @@ static irqreturn_t snd_als300plus_interrupt(int irq, void *dev_id)
>  	return IRQ_HANDLED;
>  }
>  
> -static void snd_als300_remove(struct pci_dev *pci)
> -{
> -	snd_card_free(pci_get_drvdata(pci));
> -}
> -
>  static unsigned short snd_als300_ac97_read(struct snd_ac97 *ac97,
>  							unsigned short reg)
>  {
> @@ -610,35 +595,22 @@ static void snd_als300_init(struct snd_als300 *chip)
>  }
>  
>  static int snd_als300_create(struct snd_card *card,
> -			     struct pci_dev *pci, int chip_type,
> -			     struct snd_als300 **rchip)
> +			     struct pci_dev *pci, int chip_type)
>  {
> -	struct snd_als300 *chip;
> +	struct snd_als300 *chip = card->private_data;
>  	void *irq_handler;
>  	int err;
>  
> -	static const struct snd_device_ops ops = {
> -		.dev_free = snd_als300_dev_free,
> -	};
> -	*rchip = NULL;
> -
> -	err = pci_enable_device(pci);
> +	err = pcim_enable_device(pci);
>  	if (err < 0)
>  		return err;
>  
>  	if (dma_set_mask_and_coherent(&pci->dev, DMA_BIT_MASK(28))) {
>  		dev_err(card->dev, "error setting 28bit DMA mask\n");
> -		pci_disable_device(pci);
>  		return -ENXIO;
>  	}
>  	pci_set_master(pci);
>  
> -	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
> -	if (chip == NULL) {
> -		pci_disable_device(pci);
> -		return -ENOMEM;
> -	}
> -
>  	chip->card = card;
>  	chip->pci = pci;
>  	chip->irq = -1;
> @@ -646,11 +618,9 @@ static int snd_als300_create(struct snd_card *card,
>  	spin_lock_init(&chip->reg_lock);
>  
>  	err = pci_request_regions(pci, "ALS300");
> -	if (err < 0) {
> -		kfree(chip);
> -		pci_disable_device(pci);
> +	if (err < 0)
>  		return err;
> -	}
> +
>  	chip->port = pci_resource_start(pci, 0);
>  
>  	if (chip->chip_type == DEVICE_ALS300_PLUS)
> @@ -658,38 +628,29 @@ static int snd_als300_create(struct snd_card *card,
>  	else
>  		irq_handler = snd_als300_interrupt;
>  
> -	if (request_irq(pci->irq, irq_handler, IRQF_SHARED,
> -			KBUILD_MODNAME, chip)) {
> +	if (devm_request_irq(&pci->dev, pci->irq, irq_handler, IRQF_SHARED,
> +			     KBUILD_MODNAME, chip)) {
>  		dev_err(card->dev, "unable to grab IRQ %d\n", pci->irq);
> -		snd_als300_free(chip);
>  		return -EBUSY;
>  	}
>  	chip->irq = pci->irq;
>  	card->sync_irq = chip->irq;
> +	card->private_free = snd_als300_free;
>  
>  	snd_als300_init(chip);
>  
>  	err = snd_als300_ac97(chip);
>  	if (err < 0) {
>  		dev_err(card->dev, "Could not create ac97\n");
> -		snd_als300_free(chip);
>  		return err;
>  	}
>  
>  	err = snd_als300_new_pcm(chip);
>  	if (err < 0) {
>  		dev_err(card->dev, "Could not create PCM\n");
> -		snd_als300_free(chip);
> -		return err;
> -	}
> -
> -	err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
> -	if (err < 0) {
> -		snd_als300_free(chip);
>  		return err;
>  	}
>  
> -	*rchip = chip;
>  	return 0;
>  }
>  
> @@ -737,20 +698,16 @@ static int snd_als300_probe(struct pci_dev *pci,
>  		return -ENOENT;
>  	}
>  
> -	err = snd_card_new(&pci->dev, index[dev], id[dev], THIS_MODULE,
> -			   0, &card);
> -
> +	err = snd_devm_card_new(&pci->dev, index[dev], id[dev], THIS_MODULE,
> +				sizeof(*chip), &card);
>  	if (err < 0)
>  		return err;
>  
>  	chip_type = pci_id->driver_data;
>  
> -	err = snd_als300_create(card, pci, chip_type, &chip);
> -	if (err < 0) {
> -		snd_card_free(card);
> +	err = snd_als300_create(card, pci, chip_type);
> +	if (err < 0)
>  		return err;
> -	}
> -	card->private_data = chip;
>  
>  	strcpy(card->driver, "ALS300");
>  	if (chip->chip_type == DEVICE_ALS300_PLUS)

clang warns:

sound/pci/als300.c:713:6: error: variable 'chip' is uninitialized when used here [-Werror,-Wuninitialized]
        if (chip->chip_type == DEVICE_ALS300_PLUS)
            ^~~~
sound/pci/als300.c:691:25: note: initialize the variable 'chip' to silence this warning
        struct snd_als300 *chip;
                               ^
                                = NULL
1 error generated.

> @@ -764,10 +721,9 @@ static int snd_als300_probe(struct pci_dev *pci,
>  				card->shortname, chip->port, chip->irq);
>  
>  	err = snd_card_register(card);
> -	if (err < 0) {
> -		snd_card_free(card);
> +	if (err < 0)
>  		return err;
> -	}
> +
>  	pci_set_drvdata(pci, card);
>  	dev++;
>  	return 0;
> @@ -777,7 +733,6 @@ static struct pci_driver als300_driver = {
>  	.name = KBUILD_MODNAME,
>  	.id_table = snd_als300_ids,
>  	.probe = snd_als300_probe,
> -	.remove = snd_als300_remove,
>  	.driver = {
>  		.pm = SND_ALS300_PM_OPS,
>  	},
> -- 
> 2.26.2