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Date:   Mon, 19 Oct 2020 00:14:28 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@iki.fi>
To:     Jerry Snitselaar <jsnitsel@redhat.com>
Cc:     linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        jarkko@kernel.org, Peter Huewe <peterhuewe@gmx.de>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Hans de Goede <hdegoede@redhat.com>,
        James Bottomley <James.Bottomley@HansenPartnership.com>
Subject: Re: [PATCH] tpm_tis: Disable interrupts on ThinkPad T490s
Message-ID: <20201018211428.GD575510@kapsi.fi>
References: <20201015214430.17937-1-jsnitsel@redhat.com>
 <20201018211143.GC575510@kapsi.fi>
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On Mon, Oct 19, 2020 at 12:11:44AM +0300, Jarkko Sakkinen wrote:
> On Thu, Oct 15, 2020 at 02:44:30PM -0700, Jerry Snitselaar wrote:
> > There is a misconfiguration in the bios of the gpio pin used for the
> > interrupt in the T490s. When interrupts are enabled in the tpm_tis
> > driver code this results in an interrupt storm. This was initially
> > reported when we attempted to enable the interrupt code in the tpm_tis
> > driver, which previously wasn't setting a flag to enable it. Due to
> > the reports of the interrupt storm that code was reverted and we went back
> > to polling instead of using interrupts. Now that we know the T490s problem
> > is a firmware issue, add code to check if the system is a T490s and
> > disable interrupts if that is the case. This will allow us to enable
> > interrupts for everyone else. If the user has a fixed bios they can
> > force the enabling of interrupts with tpm_tis.interrupts=1 on the
> > kernel command line.
> > 
> > Cc: jarkko@kernel.org
> > Cc: Peter Huewe <peterhuewe@gmx.de>
> > Cc: Jason Gunthorpe <jgg@ziepe.ca>
> > Cc: Hans de Goede <hdegoede@redhat.com>
> > Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> > Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
> 
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> 
> I'll apply this and make it available in linux-next.

Applied.

Thank you.

/Jarkko