From 8daeaea99caabe24a0929fac17977ebfb882fa86 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Thu, 26 Dec 2019 20:12:23 +0100 Subject: clk: meson: meson8b: make the CCF use the glitch-free mali mux The "mali_0" or "mali_1" clock trees should not be updated while the clock is running. Enforce this by setting CLK_SET_RATE_GATE on the "mali_0" and "mali_1" gates. This makes the CCF switch to the "mali_1" tree when "mali_0" is currently active and vice versa, which is exactly what the vendor driver does when updating the frequency of the mali clock. This fixes a potential hang when changing the GPU frequency at runtime. Fixes: 74e1f2521f16ff ("clk: meson: meson8b: add the GPU clock tree") Signed-off-by: Martin Blumenstingl Signed-off-by: Jerome Brunet --- drivers/clk/meson/meson8b.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'drivers/clk/meson') diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c index 3408297bff65..9fd31f23b2a9 100644 --- a/drivers/clk/meson/meson8b.c +++ b/drivers/clk/meson/meson8b.c @@ -1772,8 +1772,11 @@ static struct clk_regmap meson8b_hdmi_sys = { /* * The MALI IP is clocked by two identical clocks (mali_0 and mali_1) - * muxed by a glitch-free switch on Meson8b and Meson8m2. Meson8 only - * has mali_0 and no glitch-free mux. + * muxed by a glitch-free switch on Meson8b and Meson8m2. The CCF can + * actually manage this glitch-free mux because it does top-to-bottom + * updates the each clock tree and switches to the "inactive" one when + * CLK_SET_RATE_GATE is set. + * Meson8 only has mali_0 and no glitch-free mux. */ static const struct clk_parent_data meson8b_mali_0_1_parent_data[] = { { .fw_name = "xtal", .name = "xtal", .index = -1, }, @@ -1838,7 +1841,7 @@ static struct clk_regmap meson8b_mali_0 = { &meson8b_mali_0_div.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_PARENT, + .flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT, }, }; @@ -1893,7 +1896,7 @@ static struct clk_regmap meson8b_mali_1 = { &meson8b_mali_1_div.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_PARENT, + .flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT, }, }; -- cgit v1.2.3