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From:   Neil Armstrong <neil.armstrong@linaro.org>
Date:   Fri, 24 Nov 2023 09:41:20 +0100
Subject: [PATCH v9 09/12] drm/meson: gate px_clk when setting rate
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To:     Jerome Brunet <jbrunet@baylibre.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Kevin Hilman <khilman@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Jagan Teki <jagan@amarulasolutions.com>,
        Nicolas Belin <nbelin@baylibre.com>,
        Vinod Koul <vkoul@kernel.org>,
        Kishon Vijay Abraham I <kishon@kernel.org>,
        Remi Pommarel <repk@triplefau.lt>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>
Cc:     linux-clk@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        dri-devel@lists.freedesktop.org, linux-phy@lists.infradead.org,
        Rob Herring <robh@kernel.org>,
        Neil Armstrong <neil.armstrong@linaro.org>
Precedence: bulk

Disable the px_clk when setting the rate to recover a fully
configured and correctly reset VCLK clock tree after the rate
is set.

Fixes: 77d9e1e6b846 ("drm/meson: add support for MIPI-DSI transceiver")
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/gpu/drm/meson/meson_dw_mipi_dsi.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
index e5fe4e994f43..72abe2057ec3 100644
--- a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
+++ b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
@@ -95,6 +95,7 @@ static int dw_mipi_dsi_phy_init(void *priv_data)
 		return ret;
 	}
 
+	clk_disable_unprepare(mipi_dsi->px_clk);
 	ret = clk_set_rate(mipi_dsi->px_clk, mipi_dsi->mode->clock * 1000);
 
 	if (ret) {
@@ -103,6 +104,12 @@ static int dw_mipi_dsi_phy_init(void *priv_data)
 		return ret;
 	}
 
+	ret = clk_prepare_enable(mipi_dsi->px_clk);
+	if (ret) {
+		dev_err(mipi_dsi->dev, "Failed to enable DSI Pixel clock (ret %d)\n", ret);
+		return ret;
+	}
+
 	switch (mipi_dsi->dsi_device->format) {
 	case MIPI_DSI_FMT_RGB888:
 		dpi_data_format = DPI_COLOR_24BIT;

-- 
2.34.1