Path: csiph.com!news.mixmin.net!news.unit0.net!news.panservice.it!bofh.it!news.nic.it!robomod From: Enric Balletbo i Serra Newsgroups: linux.kernel Subject: Re: [tpmdd-devel] [PATCH 1/2] tpm: Apply an adapterlimit for retransmission. Date: Wed, 22 Feb 2017 12:20:03 +0100 Message-ID: References: X-Original-To: Andrew Lunn User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 31 Organization: linux.* mail to news gateway X-Original-Cc: Peter Huewe , Marcel Selhorst , apronin@google.com, tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org X-Original-Date: Wed, 22 Feb 2017 12:16:08 +0100 X-Original-Message-ID: X-Original-References: <20170221144500.502-1-enric.balletbo@collabora.com> <20170221162948.GD25818@lunn.ch> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1586076 Hi Andrew, Removing Bryan Freed from the loop as seems his email is not valid anymore. I already CC'ied Andrey which is doing the TPM bit in chromeos kernel. On 21/02/17 17:29, Andrew Lunn wrote: > On Tue, Feb 21, 2017 at 03:44:59PM +0100, Enric Balletbo i Serra wrote: >> From: Bryan Freed >> >> When the I2C Infineon part is attached to an I2C adapter that imposes >> a size limitation, large requests will fail -EINVAL. >> Retry them with size backoff without re-issuing the 0x05 command >> as this appears to occasionally put the TPM in a bad state. > > Hi Enric > > Rather than trying small and smaller transfers, would it not be better > to get the i2c core to expose the quirk info about transfer limits? > Sounds a good idea to me, I guess the quirk info can be accessed with tpm_dev.client->adapter->quirks->max_read_len so I think we don't need to touch the i2c core. I'll propose a second version of the patch. Thanks, Enric > Andrew >