linux-kernel - Re: [PATCH v2 1/3] tpm_tis: Disable interrupt auto probing on a per-device basis

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Date:	Tue, 1 Dec 2015 20:19:18 +0100
From:	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>
To:	Jason Gunthorpe <jgunthorpe@...idianresearch.com>
Cc:	Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
	tpmdd-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org,
	Martin Wilck <Martin.Wilck@...fujitsu.com>,
	Peter Huewe <peterhuewe@....de>
Subject: Re: [PATCH v2 1/3] tpm_tis: Disable interrupt auto probing on a
 per-device basis

Hello,

On Tue, Dec 01, 2015 at 11:58:27AM -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.
> 
> Signed-off-by: Jason Gunthorpe <jgunthorpe@...idianresearch.com>
> ---
>  drivers/char/tpm/tpm_tis.c | 16 +++++++---------
>  1 file changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
> index 8a3509cb10da..0a2d94f3d679 100644
> --- a/drivers/char/tpm/tpm_tis.c
> +++ b/drivers/char/tpm/tpm_tis.c
> @@ -69,7 +69,7 @@ enum tis_defaults {
>  struct tpm_info {
>  	unsigned long start;
>  	unsigned long len;
> -	unsigned int irq;
> +	int irq;

I'd add a comment here about the possible values of irq and their
interpretation. Something like:

	/*
	 * irq > 0 means: use irq $irq;
	 * irq = 0 means: autoprobe for an irq;
	 * irq = -1 means: no irq support
	 */

>  };
>  
>  static struct tpm_info tis_default_info = {
> @@ -807,7 +807,7 @@ 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 +895,9 @@ 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 +906,7 @@ 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;

It's definitly a nice improvement of this patch that the init functions
don't change the module parameter any more. (I didn't check if all
changes are gone now, but at least it's two modifications less.)

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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