linux-kernel - Re: [PATCH] CHROMIUM: tpm: tpm_tis_i2c: Lock the I2C adapter for a sequence of requests.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <201205022254.33707.PeterHuewe@gmx.de>
Date:	Wed, 2 May 2012 22:54:33 +0200
From:	Peter Hüwe <PeterHuewe@....de>
To:	Bryan Freed <bfreed@...omium.org>
Cc:	Peter Huewe <peter.huewe@...ineon.com>,
	Rajiv Andrade <srajiv@...ux.vnet.ibm.com>, tpmdd@...horst.net,
	tpmdd-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org,
	Olof Johansson <olof@...om.net>
Subject: Re: [PATCH] CHROMIUM: tpm: tpm_tis_i2c: Lock the I2C adapter for a sequence of requests.

Am Mittwoch 02 Mai 2012, 21:06:14 schrieb Bryan Freed:
> We could (in the unmodified version of this driver) replace all the
> iic_tpm_read() calls of one byte (which sends an address byte before
> reading a data byte) with an i2c_smbus_read_byte_command() call which
> does the same thing.

Unfortunately we have to use two seperate transfers (write/read) for a single 
byte read as the device does not support "repeated start" conditions and will 
simply fail to respond.

The device has some quirks that the driver has to workaround,
one is the repeated start problem, the other is the locking of the device.
If you can come up with a better solution I'd like to try it out if it's 
compatible with the device.

Thanks,
Peter
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/