linux-kernel - Re: [BISECTED] tpm CLKRUN breaks PS/2 keyboard and touchpad on Braswell system

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Date:   Tue, 19 Dec 2017 14:10:25 +0100
From:   Javier Martinez Canillas <javierm@...hat.com>
To:     Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
Cc:     Jason Gunthorpe <jgg@...pe.ca>, James Ettle <james@...le.org.uk>,
        linux-integrity@...r.kernel.org, azhar.shaikh@...el.com,
        linux-kernel@...r.kernel.org, james.l.morris@...cle.com
Subject: Re: [BISECTED] tpm CLKRUN breaks PS/2 keyboard and touchpad on
 Braswell system

Hello Jarkko,

On 12/19/2017 01:59 PM, Jarkko Sakkinen wrote:
> James, Javier, thank you for sorting this out. I'll just have couple of
> minor comments on the patch.
> 
> On Mon, Dec 18, 2017 at 01:22:28PM +0100, Javier Martinez Canillas wrote:
>> +	u32 vendor, intfcaps, intmask, clkrun_val;
> 
> Could these split into four lines (one declaration per line)?
>

Yes, I didn't like that either but did this way for consistency with the driver.

>>  	u8 rid;
>>  	int rc, probe;
>>  	struct tpm_chip *chip;
>> @@ -772,6 +772,15 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>  					ILB_REMAP_SIZE);
>>  		if (!priv->ilb_base_addr)
>>  			return -ENOMEM;
>> +
>> +		clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
>> +		/* Check if CLKRUN# is already not enabled in the LPC bus */
> 
> /* 
> 
>> +		if (!(clkrun_val & LPC_CLKRUN_EN)) {
>> +			priv->flags |= TPM_TIS_CLK_ENABLE;
> 
> Is the flag added just so surpress those WARN()'s?
>

I believe so. I just included here again for consistency, but I think the flag
and the warns can just go away.

> I've forgot why the WARN()'s even exist assuming that driver is
> functioning correctly.
> 
> /Jarkko
>

If you agree with the patch, I can post it as a formal patch on a series that
do these cleanups as preparatory work. I've also noticed a NULL pointer deref
bug in an error path so I'll also fix that too.

Best regards,
-- 
Javier Martinez Canillas
Software Engineer - Desktop Hardware Enablement
Red Hat