linux-kernel - Re: [PATCH 1/1] clk: imx6: refine hdmi_isfr's parent to make HDMI work on i.MX6 SoCs w/o VPU

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Date:   Wed, 27 Sep 2017 19:00:06 -0300
From:   Fabio Estevam <festevam@...il.com>
To:     Sébastien Szymanski 
        <sebastien.szymanski@...adeus.com>
Cc:     linux-kernel <linux-kernel@...r.kernel.org>,
        Nicolas Colombain <nicolas.colombain@...adeus.com>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...eaurora.org>,
        Julien Boibessot <julien.boibessot@...adeus.com>,
        Fabien Marteau <fabien.marteau@...adeus.com>,
        Sascha Hauer <kernel@...gutronix.de>,
        Fabio Estevam <fabio.estevam@....com>,
        Shawn Guo <shawnguo@...nel.org>, linux-clk@...r.kernel.org,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 1/1] clk: imx6: refine hdmi_isfr's parent to make HDMI
 work on i.MX6 SoCs w/o VPU

On Tue, Aug 1, 2017 at 7:40 AM, Sébastien Szymanski
<sebastien.szymanski@...adeus.com> wrote:
> On i.MX6 SoCs without VPU (in my case MCIMX6D4AVT10AC), the hdmi driver
> fails to probe:
>
> [    2.540030] dwhdmi-imx 120000.hdmi: Unsupported HDMI controller
> (0000:00:00)
> [    2.548199] imx-drm display-subsystem: failed to bind 120000.hdmi
> (ops dw_hdmi_imx_ops): -19
> [    2.557403] imx-drm display-subsystem: master bind failed: -19
>
> That's because hdmi_isfr's parent, video_27m, is not correctly ungated.
> As explained in commit 5ccc248cc537 ("ARM: imx6q: clk: Add support for
> mipi_core_cfg clock as a shared clock gate"), video_27m is gated by
> CCM_CCGR3[CG8].
>
> On i.MX6 SoCs with VPU, the hdmi is working thanks to the
> CCM_CMEOR[mod_en_ov_vpu] bit which makes the video_27m ungated whatever
> is in CCM_CCGR3[CG8]. The issue can be reproduced by setting
> CCMEOR[mod_en_ov_vpu] to 0.
>
> Make the HDMI work in every case by setting hdmi_isfr's parent to
> mipi_core_cfg.
>
> Signed-off-by: Sébastien Szymanski <sebastien.szymanski@...adeus.com>

Reviewed-by: Fabio Estevam <fabio.estevam@....com>