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drm/sun4i: hdmi: Fix usage of TMDS clock

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[ Upstream commit 5e1bc251ce ]

Although TMDS clock is required for HDMI to properly function,
nobody called clk_prepare_enable(). This fixes reference counting
issues and makes sure clock is running when it needs to be running.

Due to TDMS clock being parent clock for DDC clock, TDMS clock
was turned on/off for each EDID probe, causing spurious failures
for certain HDMI/DVI screens.

Fixes: 9c5681011a ("drm/sun4i: Add HDMI support")
Signed-off-by: Priit Laes <priit.laes@paf.com>
[Maxime: Moved the TMDS clock enable earlier]
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190122073232.7240-1-plaes@plaes.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Priit Laes 2019-01-22 09:32:32 +02:00 committed by Greg Kroah-Hartman
parent 89d9a53346
commit f735773532
1 changed files with 4 additions and 0 deletions
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4
drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
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@ -92,6 +92,8 @@ static void sun4i_hdmi_disable(struct drm_encoder *encoder)
val = readl(hdmi->base + SUN4I_HDMI_VID_CTRL_REG);
val &= ~SUN4I_HDMI_VID_CTRL_ENABLE;
writel(val, hdmi->base + SUN4I_HDMI_VID_CTRL_REG);
clk_disable_unprepare(hdmi->tmds_clk);
}
static void sun4i_hdmi_enable(struct drm_encoder *encoder)
@ -102,6 +104,8 @@ static void sun4i_hdmi_enable(struct drm_encoder *encoder)
DRM_DEBUG_DRIVER("Enabling the HDMI Output\n");
clk_prepare_enable(hdmi->tmds_clk);
sun4i_hdmi_setup_avi_infoframes(hdmi, mode);
val |= SUN4I_HDMI_PKT_CTRL_TYPE(0, SUN4I_HDMI_PKT_AVI);
val |= SUN4I_HDMI_PKT_CTRL_TYPE(1, SUN4I_HDMI_PKT_END);