From mboxrd@z Thu Jan 1 00:00:00 1970 From: jilaiw@codeaurora.org Subject: Re: [PATCH 2/2] drm/msm/hdmi: add hdmi hdcp support (V2) Date: Wed, 11 Feb 2015 18:59:16 -0000 Message-ID: <57a94c8e1c4b020eb27efa8c31f149b6.squirrel@www.codeaurora.org> References: <250d9d48a62a2a46dba33a6f888fdd9e.squirrel@codeaurora.org> <1421181800-24323-1-git-send-email-jilaiw@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:33700 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752452AbbBKS7R (ORCPT ); Wed, 11 Feb 2015 13:59:17 -0500 In-Reply-To: Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Bjorn Andersson Cc: Jilai Wang , "dri-devel@lists.freedesktop.org" , linux-arm-msm , "linux-kernel@vger.kernel.org" , Rob Clark There is one issue to use i2c_smbus_XX functions: i2c_smbus_read_i2c_block_data has limitation with the maximum count I2C_SMBUS_BLOCK_MAX. But in function hdmi_hdcp_recv_ksv_fifo, since the downstream ksv_fifo size will exceed this limitation and must be read in a single transaction, we can't use this function then. > On Fri, Jan 30, 2015 at 2:39 PM, Bjorn Andersson wrote: >> On Fri, Jan 30, 2015 at 1:51 PM, Bjorn Andersson wrote: >>> On Tue, Jan 13, 2015 at 12:43 PM, Jilai Wang >>> wrote: >>>> Add HDMI HDCP support including HDCP PartI/II/III authentication. >>>> V1: Initial Change >>>> V2: Address Bjorn&Rob's comments >>>> Refactor the authentication process to use single work instead >>>> of multiple work for different authentication stages. >>>> >>> Looks cleaner and the SCM parts look good now. >>> >>> But the ddc communication still makes me wonder, see below. >>> >> >> Rob made me aware about the fact that the hdmi driver is both >> implementing a driver for the i2c controller and now for the hdcp >> client and hence doesn't have an i2c_client handle. >> >> So unless this is redesigned to be split in a separate i2c client >> driver we probably have to have the ddc functions like this. >> >> I'm fine with this as is for now. >> > > After digging some more in the i2c stack I found others using > i2c_new_dummy() to create a "dummy" i2c client from and adaptor and an > address. > By introducing that we could make hdmi->i2c an actual i2c_client and > use the client api in here. > > Regards, > Bjorn >