[PATCH 4.8 28/33] ARM: dts: imx7d: fix LCDIF clock assignment

From: Greg Kroah-Hartman
Date: Tue Dec 13 2016 - 12:18:20 EST


4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Stefan Agner <stefan@xxxxxxxx>

commit 4b707fa00a80b19b80bc8df6f1cbf4bdd9c91402 upstream.

The eLCDIF IP of the i.MX 7 SoC knows multiple clocks and lists them
separately:

Clock Clock Root Description
apb_clk MAIN_AXI_CLK_ROOT AXI clock
pix_clk LCDIF_PIXEL_CLK_ROOT Pixel clock
ipg_clk_s MAIN_AXI_CLK_ROOT Peripheral access clock

All of them are switched by a single gate, which is part of the
IMX7D_LCDIF_PIXEL_ROOT_CLK clock. Hence using that clock also for
the AXI bus clock (clock-name "axi") makes sure the gate gets
enabled when accessing registers.

There seem to be no separate AXI display clock, and the clock is
optional. Hence remove the dummy clock.

This fixes kernel freezes when starting the X-Server (which
disables/re-enables the display controller).

Fixes: e8ed73f691bd ("ARM: dts: imx7d: add lcdif support")
Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
Reviewed-by: Fabio Estevam <fabio.estevam@xxxxxxx>
Acked-by: Shawn Guo <shawnguo@xxxxxxxxxx>
Signed-off-by: Olof Johansson <olof@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arm/boot/dts/imx7s.dtsi | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/arch/arm/boot/dts/imx7s.dtsi
+++ b/arch/arm/boot/dts/imx7s.dtsi
@@ -640,9 +640,8 @@
reg = <0x30730000 0x10000>;
interrupts = <GIC_SPI 5 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clks IMX7D_LCDIF_PIXEL_ROOT_CLK>,
- <&clks IMX7D_CLK_DUMMY>,
- <&clks IMX7D_CLK_DUMMY>;
- clock-names = "pix", "axi", "disp_axi";
+ <&clks IMX7D_LCDIF_PIXEL_ROOT_CLK>;
+ clock-names = "pix", "axi";
status = "disabled";
};
};