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In-Reply-To: <496aecbe04aa460572d4ff02a64e77ca01368316.1594230107.git-series.maxime@cerno.tech>
From:   Dave Stevenson <dave.stevenson@raspberrypi.com>
Date:   Tue, 28 Jul 2020 16:04:55 +0100
Message-ID: <CAPY8ntDwJfBFLmJA8cHpkKXu5EicsZWoa8f7Pvh8jPuXYQ_ScQ@mail.gmail.com>
Subject: Re: [PATCH v4 71/78] drm/vc4: hdmi: Implement finer-grained hooks
To:     Maxime Ripard <maxime@cerno.tech>
Cc:     Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
        Eric Anholt <eric@anholt.net>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        linux-rpi-kernel@lists.infradead.org,
        bcm-kernel-feedback-list@broadcom.com,
        linux-arm-kernel@lists.infradead.org,
        LKML <linux-kernel@vger.kernel.org>,
        Tim Gover <tim.gover@raspberrypi.com>,
        Phil Elwell <phil@raspberrypi.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Maxime

On Wed, 8 Jul 2020 at 18:44, Maxime Ripard <maxime@cerno.tech> wrote:
>
> In order to prevent some pixels getting stuck in an unflushable FIFO on
> bcm2711, we need to enable the HVS, the pixelvalve (the CRTC) and the HDMI
> controller (the encoder) in an intertwined way, and with tight delays.
>
> However, the atomic callbacks don't really provide a way to work with
> either constraints, so we need to roll our own callbacks so that we can
> provide those guarantees.
>
> Since those callbacks have been implemented and called in the CRTC code, we
> can just implement them in the HDMI driver now.
>
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

> ---
>  drivers/gpu/drm/vc4/vc4_hdmi.c | 39 +++++++++++++++++++++++++++++++----
>  1 file changed, 35 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 00592c1ada73..bbe521ab000b 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -320,12 +320,17 @@ static void vc4_hdmi_set_infoframes(struct drm_encoder *encoder)
>                 vc4_hdmi_set_audio_infoframe(encoder);
>  }
>
> -static void vc4_hdmi_encoder_disable(struct drm_encoder *encoder)
> +static void vc4_hdmi_encoder_post_crtc_disable(struct drm_encoder *encoder)
>  {
>         struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> -       int ret;
>
>         HDMI_WRITE(HDMI_RAM_PACKET_CONFIG, 0);
> +}
> +
> +static void vc4_hdmi_encoder_post_crtc_powerdown(struct drm_encoder *encoder)
> +{
> +       struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> +       int ret;
>
>         if (vc4_hdmi->variant->phy_disable)
>                 vc4_hdmi->variant->phy_disable(vc4_hdmi);
> @@ -341,6 +346,10 @@ static void vc4_hdmi_encoder_disable(struct drm_encoder *encoder)
>                 DRM_ERROR("Failed to release power domain: %d\n", ret);
>  }
>
> +static void vc4_hdmi_encoder_disable(struct drm_encoder *encoder)
> +{
> +}
> +
>  static void vc4_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi, bool enable)
>  {
>         u32 csc_ctl;
> @@ -449,11 +458,10 @@ static void vc4_hdmi_recenter_fifo(struct vc4_hdmi *vc4_hdmi)
>                   "VC4_HDMI_FIFO_CTL_RECENTER_DONE");
>  }
>
> -static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
> +static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder)
>  {
>         struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
>         struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> -       struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
>         unsigned long pixel_rate, hsm_rate;
>         int ret;
>
> @@ -521,6 +529,13 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
>
>         if (vc4_hdmi->variant->set_timings)
>                 vc4_hdmi->variant->set_timings(vc4_hdmi, mode);
> +}
> +
> +static void vc4_hdmi_encoder_pre_crtc_enable(struct drm_encoder *encoder)
> +{
> +       struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
> +       struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
> +       struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
>
>         if (vc4_encoder->hdmi_monitor &&
>             drm_default_rgb_quant_range(mode) == HDMI_QUANTIZATION_RANGE_LIMITED) {
> @@ -536,6 +551,13 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
>         }
>
>         HDMI_WRITE(HDMI_FIFO_CTL, VC4_HDMI_FIFO_CTL_MASTER_SLAVE_N);
> +}
> +
> +static void vc4_hdmi_encoder_post_crtc_enable(struct drm_encoder *encoder)
> +{
> +       struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> +       struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
> +       int ret;
>
>         HDMI_WRITE(HDMI_VID_CTL,
>                    HDMI_READ(HDMI_VID_CTL) |
> @@ -582,6 +604,10 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
>         vc4_hdmi_recenter_fifo(vc4_hdmi);
>  }
>
> +static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
> +{
> +}
> +
>  static enum drm_mode_status
>  vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder,
>                             const struct drm_display_mode *mode)
> @@ -1362,6 +1388,11 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
>         dev_set_drvdata(dev, vc4_hdmi);
>         encoder = &vc4_hdmi->encoder.base.base;
>         vc4_hdmi->encoder.base.type = variant->encoder_type;
> +       vc4_hdmi->encoder.base.pre_crtc_configure = vc4_hdmi_encoder_pre_crtc_configure;
> +       vc4_hdmi->encoder.base.pre_crtc_enable = vc4_hdmi_encoder_pre_crtc_enable;
> +       vc4_hdmi->encoder.base.post_crtc_enable = vc4_hdmi_encoder_post_crtc_enable;
> +       vc4_hdmi->encoder.base.post_crtc_disable = vc4_hdmi_encoder_post_crtc_disable;
> +       vc4_hdmi->encoder.base.post_crtc_powerdown = vc4_hdmi_encoder_post_crtc_powerdown;
>         vc4_hdmi->pdev = pdev;
>         vc4_hdmi->variant = variant;
>
> --
> git-series 0.9.1