ARM: dts: imx7d: fix LCDIF clock assignment

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@agner.ch>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/boot/dts/imx7s.dtsi b/arch/arm/boot/dts/imx7s.dtsi
index 1e90bdbe3a6ea36efe6ade1c6f4d692dc480bd32..fb307de5422cf9b7d0362748ac0f7f6c4be18fc6 100644 (file)
--- 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";
                        };
                };