linux-kernel - Re: [PATCH v2 15/15] drm/mediatek: Introduce HDMI/DDC v2 for MT8195/MT8188

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <50757699-aca2-423a-b463-5a4d74d63447@collabora.com>
Date: Tue, 10 Dec 2024 09:33:22 +0100
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
To: CK Hu (胡俊光) <ck.hu@...iatek.com>,
 "chunkuang.hu@...nel.org" <chunkuang.hu@...nel.org>
Cc: "robh@...nel.org" <robh@...nel.org>,
 "jie.qiu@...iatek.com" <jie.qiu@...iatek.com>,
 "tzimmermann@...e.de" <tzimmermann@...e.de>,
 "simona@...ll.ch" <simona@...ll.ch>, "mripard@...nel.org"
 <mripard@...nel.org>, Jitao Shi (石记涛)
 <jitao.shi@...iatek.com>,
 "linux-mediatek@...ts.infradead.org" <linux-mediatek@...ts.infradead.org>,
 "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
 "maarten.lankhorst@...ux.intel.com" <maarten.lankhorst@...ux.intel.com>,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
 "kernel@...labora.com" <kernel@...labora.com>,
 "krzk+dt@...nel.org" <krzk+dt@...nel.org>,
 "p.zabel@...gutronix.de" <p.zabel@...gutronix.de>,
 "conor+dt@...nel.org" <conor+dt@...nel.org>,
 "airlied@...il.com" <airlied@...il.com>,
 "linux-arm-kernel@...ts.infradead.org"
 <linux-arm-kernel@...ts.infradead.org>,
 "matthias.bgg@...il.com" <matthias.bgg@...il.com>,
 "junzhi.zhao@...iatek.com" <junzhi.zhao@...iatek.com>
Subject: Re: [PATCH v2 15/15] drm/mediatek: Introduce HDMI/DDC v2 for
 MT8195/MT8188

Il 10/12/24 04:28, CK Hu (胡俊光) ha scritto:
> Hi, Angelo:
> 
> On Thu, 2024-12-05 at 12:45 +0100, AngeloGioacchino Del Regno wrote:
>> External email : Please do not click links or open attachments until you have verified the sender or the content.
>>
>>
>> Add support for the newer HDMI-TX (Encoder) v2 and DDC v2 IPs
>> found in MediaTek's MT8195, MT8188 SoC and their variants, and
>> including support for display modes up to 4k60 and for HDMI
>> Audio, as per the HDMI 2.0 spec.
>>
>> HDCP and CEC functionalities are also supported by this hardware,
>> but are not included in this commit and that also poses a slight
>> difference between the V2 and V1 controllers in how they handle
>> Hotplug Detection (HPD).
>>
>> While the v1 controller was using the CEC controller to check
>> HDMI cable connection and disconnection, in this driver the v2
>> one does not.
>>
>> This is due to the fact that on parts with v2 designs, like the
>> MT8195 SoC, there is one CEC controller shared between the HDMI
>> Transmitter (HDMI-TX) and Receiver (HDMI-RX): before eventually
>> adding support to use the CEC HW to wake up the HDMI controllers
>> it is necessary to have support for one TX, one RX *and* for both
>> at the same time.
>>
>> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
>> ---
> 
> [snip]
> 
>> +static void mtk_hdmi_v2_bridge_enable(struct drm_bridge *bridge,
>> +                                     struct drm_bridge_state *old_state)
>> +{
>> +       struct mtk_hdmi *hdmi = hdmi_ctx_from_bridge(bridge);
>> +       struct drm_atomic_state *state = old_state->base.state;
>> +       int ret;
>> +
>> +       ret = drm_atomic_helper_connector_hdmi_update_infoframes(hdmi->curr_conn, state);
>> +       if (ret)
>> +               dev_err(hdmi->dev, "Could not update infoframes: %d\n", ret);
>> +
>> +       mtk_hdmi_v2_hw_vid_mute(hdmi, false);
>> +       mtk_hdmi_v2_hw_aud_mute(hdmi, false);
> 
> In v1, it does not unmute when bridge enable.
> I would like v1 and v2 has the same behavior.
> If possible, remove these code.
> If remove thee code would result in some problem,
> add comment to describe why need these code.
> 

I think you even said that in the first review...

Thanks for repeating, and sorry for missing that in v2, will be done
for v3

Cheers,
Angelo

> Regards,
> CK
> 
>> +
>> +       /* signal the connect event to audio codec */
>> +       mtk_hdmi_v2_handle_plugged_change(hdmi, true);
>> +
>> +       hdmi->enabled = true;
>> +}
>> +
>