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From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
To: Andrey Pronin <apronin@chromium.org>
Cc: Peter Huewe <peterhuewe@gmx.de>,
	Marcel Selhorst <tpmdd@selhorst.net>,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org,
	semenzato@chromium.org, groeck@chromium.org
Subject: Re: [PATCH] tpm/tpm_i2c_infineon: ensure no ongoing commands on shutdown
Date: Fri, 13 Jan 2017 17:28:57 -0700	[thread overview]
Message-ID: <20170114002857.GA5851@obsidianresearch.com> (raw)
In-Reply-To: <20170114000954.17728-1-apronin@chromium.org>

On Fri, Jan 13, 2017 at 04:09:54PM -0800, Andrey Pronin wrote:
> Resetting TPM while processing a command may lead to issues
> on the next boot. Ensure that we don't have any ongoing
> commands, and that no further commands can be sent to the chip
> by unregistering the device in the shutdown handler.
> tpm_chip_unregister() waits for the completion of an ongoing
> command, if any, and then clears out chip->ops and unregisters
> sysfs entities.

Unregistering in a shutdown handler seems very strange, it also waits
for userspace things, so I wonder if it could be problematic?

Maybe just use

   down_write(&chip->ops_sem);
   chip->ops = NULL;
   up_write(&chip->ops_sem);

In the shutdown handler?

Jason

  reply	other threads:[~2017-01-14  0:30 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-14  0:09 [PATCH] tpm/tpm_i2c_infineon: ensure no ongoing commands on shutdown Andrey Pronin
2017-01-14  0:28 ` Jason Gunthorpe [this message]
2017-01-14  0:42   ` Andrey Pronin
2017-01-16  9:33     ` Jarkko Sakkinen
2017-01-25 18:59       ` [tpmdd-devel] " Jarkko Sakkinen
2017-01-16 16:19     ` Jason Gunthorpe
2017-01-17 17:58       ` Andrey Pronin
2017-01-17 19:27         ` Jason Gunthorpe
2017-01-17 20:13           ` Andrey Pronin
2017-01-17 20:59             ` Jason Gunthorpe
2017-01-17 23:00               ` Andrey Pronin
2017-01-17 23:22                 ` Jason Gunthorpe
2017-01-23 20:02                   ` Andrey Pronin
2017-01-23 20:16                     ` [tpmdd-devel] " Andrey Pronin
2017-01-23 20:39                     ` Jason Gunthorpe
2017-01-23 22:19                       ` Andrey Pronin
2017-01-23 22:57                         ` Jason Gunthorpe

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