linux-kernel - Re: [PATCH v3 2/7] tpm_tis: Disable interrupt auto probing on a per-device basis

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Message-ID: <20160103172040.GB4155@intel.com>
Date:	Sun, 3 Jan 2016 19:20:40 +0200
From:	Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To:	Jason Gunthorpe <jgunthorpe@...idianresearch.com>
Cc:	tpmdd-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org,
	Martin Wilck <Martin.Wilck@...fujitsu.com>,
	Peter Huewe <peterhuewe@....de>,
	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>
Subject: Re: [PATCH v3 2/7] tpm_tis: Disable interrupt auto probing on a
 per-device basis

On Thu, Dec 17, 2015 at 11:23:15AM -0700, Jason Gunthorpe wrote:
> Instead of clearing the global interrupts flag when any device
> does not have an interrupt just pass -1 through tpm_info.irq.
> 
> The only thing that asks for autoprobing is the force=1 path.

Sorry for my ignorance but what does this patch help? Why interrupts
flag is not enough?

> Signed-off-by: Jason Gunthorpe <jgunthorpe@...idianresearch.com>
> Tested-by: Wilck, Martin <martin.wilck@...fujitsu.com>
> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>

Did I already give Tested-by's for this series (I did for those that
went into v4.5 pull request)?

/Jarkko

> ---
>  drivers/char/tpm/tpm_tis.c | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
> index 304323bdcaaa..fecd27b45fd1 100644
> --- a/drivers/char/tpm/tpm_tis.c
> +++ b/drivers/char/tpm/tpm_tis.c
> @@ -69,7 +69,11 @@ enum tis_defaults {
>  struct tpm_info {
>  	unsigned long start;
>  	unsigned long len;
> -	unsigned int irq;
> +	/* irq > 0 means: use irq $irq;
> +	 * irq = 0 means: autoprobe for an irq;
> +	 * irq = -1 means: no irq support
> +	 */
> +	int irq;
>  };
>  
>  static struct tpm_info tis_default_info = {
> @@ -807,7 +811,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
>  	/* INTERRUPT Setup */
>  	init_waitqueue_head(&chip->vendor.read_queue);
>  	init_waitqueue_head(&chip->vendor.int_queue);
> -	if (interrupts) {
> +	if (interrupts && tpm_info->irq != -1) {
>  		if (tpm_info->irq) {
>  			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
>  						 tpm_info->irq);
> @@ -895,9 +899,9 @@ static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
>  
>  #ifdef CONFIG_PNP
>  static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
> -				      const struct pnp_device_id *pnp_id)
> +			    const struct pnp_device_id *pnp_id)
>  {
> -	struct tpm_info tpm_info = tis_default_info;
> +	struct tpm_info tpm_info = {};
>  	acpi_handle acpi_dev_handle = NULL;
>  
>  	tpm_info.start = pnp_mem_start(pnp_dev, 0);
> @@ -906,7 +910,7 @@ static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
>  	if (pnp_irq_valid(pnp_dev, 0))
>  		tpm_info.irq = pnp_irq(pnp_dev, 0);
>  	else
> -		interrupts = false;
> +		tpm_info.irq = -1;
>  
>  #ifdef CONFIG_ACPI
>  	if (pnp_acpi_device(pnp_dev)) {
> @@ -984,6 +988,7 @@ static int tpm_tis_acpi_init(struct acpi_device *acpi_dev)
>  		return -ENODEV;
>  
>  	INIT_LIST_HEAD(&resources);
> +	tpm_info.irq = -1;
>  	ret = acpi_dev_get_resources(acpi_dev, &resources, tpm_check_resource,
>  				     &tpm_info);
>  	if (ret < 0)
> @@ -991,9 +996,6 @@ static int tpm_tis_acpi_init(struct acpi_device *acpi_dev)
>  
>  	acpi_dev_free_resource_list(&resources);
>  
> -	if (!tpm_info.irq)
> -		interrupts = false;
> -
>  	if (is_itpm(acpi_dev))
>  		itpm = true;
>  
> -- 
> 2.1.4
> 
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