From: Martin Blumenstingl martin.blumenstingl@googlemail.com
[ Upstream commit 8daeaea99caabe24a0929fac17977ebfb882fa86 ]
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 martin.blumenstingl@googlemail.com Signed-off-by: Jerome Brunet jbrunet@baylibre.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/meson/meson8b.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c index 67e6691e080c1..8856ce476ccfa 100644 --- a/drivers/clk/meson/meson8b.c +++ b/drivers/clk/meson/meson8b.c @@ -1764,8 +1764,11 @@ 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_hw *meson8b_mali_0_1_parent_hws[] = { &meson8b_xtal.hw, @@ -1830,7 +1833,7 @@ 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, }, };
@@ -1885,7 +1888,7 @@ 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, }, };