linux-kernel - Re: [PATCH v2 2/4] [media] platform: Add Synopsys Designware HDMI RX Controller Driver

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Message-ID: <900bfa50-2cc3-2b33-8531-2c65ebd3a981@synopsys.com>
Date:   Fri, 16 Jun 2017 16:52:57 +0100
From:   Jose Abreu <Jose.Abreu@...opsys.com>
To:     Hans Verkuil <hverkuil@...all.nl>,
        Jose Abreu <Jose.Abreu@...opsys.com>,
        <linux-media@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <devicetree@...r.kernel.org>
CC:     Carlos Palminha <CARLOS.PALMINHA@...opsys.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Hans Verkuil <hans.verkuil@...co.com>
Subject: Re: [PATCH v2 2/4] [media] platform: Add Synopsys Designware HDMI RX
 Controller Driver

Hi Hans,


On 16-06-2017 14:44, Hans Verkuil wrote:
>
>>> <snip>
>>>
>>>> +	/* CEC */
>>>> +	dw_dev->cec_adap = cec_allocate_adapter(&dw_hdmi_cec_adap_ops,
>>>> +			dw_dev, dev_name(dev), CEC_CAP_TRANSMIT |
>>>> +			CEC_CAP_PHYS_ADDR | CEC_CAP_LOG_ADDRS,
>>> Add CEC_CAP_RC and CEC_CAP_PASSTHROUGH.
>>>
>>> I'm not sure about CEC_CAP_PHYS_ADDR. The problem here is that this driver
>>> doesn't handle the EDID, but without that it doesn't know what physical
>>> address to use.
>>>
>>> I wonder if the cec-notifier can be used for this, possibly with adaptations.
>>> Relying on users to set the physical address is a last resort since it is very
>>> painful to do so. cec-notifier was specifically designed to solve this.
>> Yes, EDID ROM is not integrated into the controller so I can't
>> add the code. How exactly can I use cec-notifier here?
> drivers/media/platform/sti/cec/stih-cec.c is a good example. The notifier is
> called by drivers/gpu/drm/sti/sti_hdmi.c.

Done! Implemented and working :) I'm wondering if you want me to
wait some more time for other comments or just send the v3 now? I
also added support for SCDC read request (its a matter of
activating a bit).

BTW, I used the DT node name "hdmi-phandle" but I don't know if
it is the best because it can cause confusion about the
hdmi-phandle that you documented in media/cec.txt

Best regards,
Jose Miguel Abreu

>
> Regards,
>
> 	Hans
>