From 5e33ebff7eddcf333287482e29541a3c06da3db5 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Sun, 3 Jul 2016 10:48:13 -0700 Subject: [PATCH] clk: imx7d: do not set parent of ethernet time/ref clocks All device trees currently in mainline specify the time clock parent using the assigned-clocks/assigned-clock-parents method, there is no need to statically assign the parent in the core clock driver. Also all current boards provide an Ethernet reference clock for the PHY externally, hence configuring the internal PHY reference clock. Furthermore, and the actual driver of this patch, specify ethernet related parents at that early point in boot leads to a warning: bad: scheduling from the idle thread! The reason for the warning is that setting the parent enables the ENET PLL since we are using CLK_OPS_PARENT_ENABLE. Enabling the ENET PLL can cause clk_pllv3_wait_lock to sleep. See also: commit fc8726a2c021 ("clk: core: support clocks which requires parents enable (part 2)"). Note that setting the ENET AXI root clock parent also requires ENET PLL to be enabled. However, U-Boot typically leaves the ENET PLL on, hence when the framework sets the parent of the first clock, it does not need to wait for the PLL to come up. But because there is currently no user of that clock, the PLL gets disabled after setting the parent. Therefore, subsequent reparenting calls of any clock which somehow rely on the ENET PLL, need to reenable the ENET PLL which leads to a sleep. Removing those subsequent reparenting calls works around this issue. Also remove comments. The code is really verbose enough. Signed-off-by: Stefan Agner Tested-by: Fabio Estevam Signed-off-by: Michael Turquette Link: lkml.kernel.org/r/20160703174813.13970-1-stefan@agner.ch --- drivers/clk/imx/clk-imx7d.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/drivers/clk/imx/clk-imx7d.c b/drivers/clk/imx/clk-imx7d.c index 79293edeb380..6ed4f8fa0667 100644 --- a/drivers/clk/imx/clk-imx7d.c +++ b/drivers/clk/imx/clk-imx7d.c @@ -860,16 +860,7 @@ static void __init imx7d_clocks_init(struct device_node *ccm_node) /* use old gpt clk setting, gpt1 root clk must be twice as gpt counter freq */ clk_set_parent(clks[IMX7D_GPT1_ROOT_SRC], clks[IMX7D_OSC_24M_CLK]); - /* - * init enet clock source: - * AXI clock source is 250MHz - * Phy refrence clock is 25MHz - * 1588 time clock source is 100MHz - */ clk_set_parent(clks[IMX7D_ENET_AXI_ROOT_SRC], clks[IMX7D_PLL_ENET_MAIN_250M_CLK]); - clk_set_parent(clks[IMX7D_ENET_PHY_REF_ROOT_SRC], clks[IMX7D_PLL_ENET_MAIN_25M_CLK]); - clk_set_parent(clks[IMX7D_ENET1_TIME_ROOT_SRC], clks[IMX7D_PLL_ENET_MAIN_100M_CLK]); - clk_set_parent(clks[IMX7D_ENET2_TIME_ROOT_SRC], clks[IMX7D_PLL_ENET_MAIN_100M_CLK]); /* set uart module clock's parent clock source that must be great then 80MHz */ clk_set_parent(clks[IMX7D_UART1_ROOT_SRC], clks[IMX7D_OSC_24M_CLK]); -- 2.30.2