From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: [tpmdd-devel] [PATCH 1/2] tpm: Apply an adapterlimit for retransmission. Date: Wed, 22 Feb 2017 15:01:34 +0100 Message-ID: <20170222140134.GA23586@lunn.ch> References: <20170221144500.502-1-enric.balletbo@collabora.com> <20170221162948.GD25818@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Enric Balletbo i Serra Cc: Peter Huewe , Marcel Selhorst , apronin@google.com, tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Wolfram Sang List-Id: tpmdd-devel@lists.sourceforge.net On Wed, Feb 22, 2017 at 12:16:08PM +0100, Enric Balletbo i Serra wrote: > 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. Hi Enric You should probably ask Wolfram Sang , the i2c subsystem maintainer. He may prefer adding an API call. Andrew