From e94b612527b408bd3f52aa30a44059c6ac9d3224 Mon Sep 17 00:00:00 2001 From: Christian Hewitt Date: Tue, 6 Nov 2018 00:08:20 +0100 Subject: [PATCH] clk: meson-gxbb: set fclk_div3 as CLK_IS_CRITICAL On the Khadas VIM2 (GXM) and LePotato (GXL) board there are problems with reboot; e.g. a ~60 second delay between issuing reboot and the board power cycling (and in some OS configurations reboot will fail and require manual power cycling). Similar to 'commit 52ae7c4a87a4485b5f7f27f30b8c9a74501c30ec ("clk: meson-gxbb: set fclk_div2 as CLK_IS_CRITICAL")' the SCPI Cortex-M4 Co-Processor seems to depend on FCLK_DIV3 being operational. Until commit 003f3d10a72f753b46919419111c19a9753bc41b ("clk: meson: add fdiv clock gates"), this clock was modeled and left on by the bootloader. We don't have precise documentation about the SCPI Co-Processor and its clock requirement so we are learning things the hard way. Marking this clock as critical solves the problem but it should not be viewed as final solution. Ideally, the SCPI driver should claim these clocks. We also depends on some clock hand-off mechanism making its way to CCF, to make sure the clock stays on between its registration and the SCPI driver probe. Fixes: 003f3d10a72f ("clk: meson: add fdiv clock gates") Signed-off-by: Christian Hewitt Signed-off-by: Jerome Brunet Signed-off-by: Stephen Boyd --- drivers/clk/meson/gxbb.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/clk/meson/gxbb.c b/drivers/clk/meson/gxbb.c index 9309cfaaa464e..4ada9668fd49c 100644 --- a/drivers/clk/meson/gxbb.c +++ b/drivers/clk/meson/gxbb.c @@ -506,6 +506,18 @@ static struct clk_regmap gxbb_fclk_div3 = { .ops = &clk_regmap_gate_ops, .parent_names = (const char *[]){ "fclk_div3_div" }, .num_parents = 1, + /* + * FIXME: + * This clock, as fdiv2, is used by the SCPI FW and is required + * by the platform to operate correctly. + * Until the following condition are met, we need this clock to + * be marked as critical: + * a) The SCPI generic driver claims and enable all the clocks + * it needs + * b) CCF has a clock hand-off mechanism to make the sure the + * clock stays on until the proper driver comes along + */ + .flags = CLK_IS_CRITICAL, }, }; -- 2.39.5