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From: jilaiw@codeaurora.org
To: Bjorn Andersson <bjorn@kryo.se>
Cc: Jilai Wang <jilaiw@codeaurora.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Rob Clark <robdclark@gmail.com>
Subject: Re: [PATCH 2/2] drm/msm/hdmi: add hdmi hdcp support (V2)
Date: Wed, 11 Feb 2015 18:59:16 -0000	[thread overview]
Message-ID: <57a94c8e1c4b020eb27efa8c31f149b6.squirrel@www.codeaurora.org> (raw)
In-Reply-To: <CAJAp7OgyH+Z5Qu+uNSSTboa=0otAi8gAc+rGpRGVFz3sZQATKg@mail.gmail.com>

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 <bjorn@kryo.se> wrote:
>> On Fri, Jan 30, 2015 at 1:51 PM, Bjorn Andersson <bjorn@kryo.se> wrote:
>>> On Tue, Jan 13, 2015 at 12:43 PM, Jilai Wang <jilaiw@codeaurora.org>
>>> 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
>

  reply	other threads:[~2015-02-11 18:59 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-01 21:56 [PATCH 2/2] drm/msm/hdmi: add hdmi hdcp support Jilai Wang
2014-12-03  1:46 ` Bjorn Andersson
2014-12-03 16:42   ` Rob Clark
2014-12-03 17:16     ` jilaiw
2014-12-03 17:20       ` Rob Clark
2014-12-03 17:32       ` Bjorn Andersson
2014-12-03 17:49         ` jilaiw
2015-01-13 20:43           ` [PATCH 2/2] drm/msm/hdmi: add hdmi hdcp support (V2) Jilai Wang
2015-01-30 21:51             ` Bjorn Andersson
2015-01-30 22:39               ` Bjorn Andersson
2015-02-10 19:34                 ` Bjorn Andersson
2015-02-11 18:59                   ` jilaiw [this message]
2015-02-11 22:23                     ` Bjorn Andersson
2015-04-02 21:49                       ` [PATCH] drm/msm/hdmi: add hdmi hdcp support (V3) Jilai Wang
2014-12-03 16:51 ` [PATCH 2/2] drm/msm/hdmi: add hdmi hdcp support Rob Clark

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