From: neil.armstrong@linaro.org
To: Theo Debrouwere <theo.debrouwere@gmail.com>,
linux-amlogic@lists.infradead.org
Cc: Theo Debrouwere <theo.debrouwere@faytech.de>
Subject: Re: [PATCH v2] drm/meson: disable line encoder before programming the gamma table
Date: Tue, 17 Sep 2024 09:07:13 +0200 [thread overview]
Message-ID: <1d668177-eafb-4c6f-9746-b62b74a5458e@linaro.org> (raw)
In-Reply-To: <20240916133530.25498-1-theo.debrouwere@faytech.de>
On 16/09/2024 15:32, Theo Debrouwere wrote:
> There is a very rare bug, where the gamma table can't be written correctly.
> It is possible to write some entries into the gamma data port, after which
> the WR_RDY bit isn't set anymore. This causes a timeout in the code, and more
> entries will be written into the table. (each having their own timeout)
> There will be an image produced, but the colors will be completely off.
> The number of entries that can be written seems random.
>
> The issue seems to be solved if the line encoder is disabled before the table
> is programmed.
>
> Fixes: 42dcf15f901c ("drm/meson: add DSI encoder")
> Signed-off-by: Theo Debrouwere <theo.debrouwere@faytech.de>
> ---
> Added Fixes tag.
>
> drivers/gpu/drm/meson/meson_encoder_dsi.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/meson/meson_encoder_dsi.c b/drivers/gpu/drm/meson/meson_encoder_dsi.c
> index 7816902f59075..15fd9df58ae4e 100644
> --- a/drivers/gpu/drm/meson/meson_encoder_dsi.c
> +++ b/drivers/gpu/drm/meson/meson_encoder_dsi.c
> @@ -66,10 +66,11 @@ static void meson_encoder_dsi_atomic_enable(struct drm_bridge *bridge,
> /* ENCL clock setup is handled by CCF */
>
> meson_venc_mipi_dsi_mode_set(priv, &crtc_state->adjusted_mode);
> - meson_encl_load_gamma(priv);
>
> writel_relaxed(0, priv->io_base + _REG(ENCL_VIDEO_EN));
>
> + meson_encl_load_gamma(priv);
> +
> writel_bits_relaxed(ENCL_VIDEO_MODE_ADV_VFIFO_EN, ENCL_VIDEO_MODE_ADV_VFIFO_EN,
> priv->io_base + _REG(ENCL_VIDEO_MODE_ADV));
> writel_relaxed(0, priv->io_base + _REG(ENCL_TST_EN));
> --
> 2.45.2
>
> _______________________________________________
> linux-amlogic mailing list
> linux-amlogic@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-amlogic
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
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prev parent reply other threads:[~2024-09-17 7:07 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-16 13:32 Theo Debrouwere
2024-09-17 7:07 ` neil.armstrong [this message]
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