From: "Winkler, Tomas" <tomas.winkler@intel.com>
To: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>,
        Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
CC: "tpmdd-devel@lists.sourceforge.net" 
        <tpmdd-devel@lists.sourceforge.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 2/4] tmp/tpm_crb: fix Intel PTT hw bug during idle state
Thread-Topic: [PATCH 2/4] tmp/tpm_crb: fix Intel PTT hw bug during idle state
Thread-Index: AQHSIVu/ZnkPL5o4ZkCC1sbu6MZMlKCeT/eAgAA/wRD///VYAIAAC7mAgAA2hpA=
Date: Sat, 8 Oct 2016 16:58:28 +0000
Message-ID: <5B8DA87D05A7694D9FA63FD143655C1B542F67DF@hasmsx108.ger.corp.intel.com>
References: <1475927979-23484-1-git-send-email-tomas.winkler@intel.com>
 <1475927979-23484-3-git-send-email-tomas.winkler@intel.com>
 <20161008125003.GB10317@intel.com>
 <5B8DA87D05A7694D9FA63FD143655C1B542F6768@hasmsx108.ger.corp.intel.com>
 <20161008160006.GA25893@intel.com>
 <20161008164203.GB29734@obsidianresearch.com>
In-Reply-To: <20161008164203.GB29734@obsidianresearch.com>
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> On Sat, Oct 08, 2016 at 07:00:06PM +0300, Jarkko Sakkinen wrote:
> 
> > Rather you it would be better not to use cmdReady/goIdle at all if
> > kernel is not compiled with CONFIG_PM.
> 
> It would be best practice to ensure the tpm is powered up no matter how the
> kernel is compiled.. The firmware may have left it in idle or something
> 
> FWIW, I broadly agree there is no need to put the device into idle on the error
> paths. It probably wasn't idle when the driver attached to it.

Actually, currently it is more common to have the device in the idle state, so in case a driver is not loaded for any reason  by the kernel, the platform won't leak power.
Thanks
Tomas