From 5aa6d84a0b076fbbbe41e9e7d5a7292b58920f11 Mon Sep 17 00:00:00 2001 From: Quentin Schulz Date: Mon, 31 Jan 2022 17:32:24 +0100 Subject: [PATCH] clk: rockchip: re-add rational best approximation algorithm to the fractional divider commit 10b74af310735860510a533433b1d3ab2e05a138 upstream. In commit 4e7cf74fa3b2 ("clk: fractional-divider: Export approximation algorithm to the CCF users"), the code handling the rational best approximation algorithm was replaced by a call to the core clk_fractional_divider_general_approximation function which did the same thing back then. However, in commit 82f53f9ee577 ("clk: fractional-divider: Introduce POWER_OF_TWO_PS flag"), this common code was made conditional on CLK_FRAC_DIVIDER_POWER_OF_TWO_PS flag which was not added back to the rockchip clock driver. This broke the ltk050h3146w-a2 MIPI DSI display present on a PX30-based downstream board. Let's add the flag to the fractional divider flags so that the original and intended behavior is brought back to the rockchip clock drivers. Fixes: 82f53f9ee577 ("clk: fractional-divider: Introduce POWER_OF_TWO_PS flag") Cc: stable@vger.kernel.org Cc: Quentin Schulz Signed-off-by: Quentin Schulz Link: https://lore.kernel.org/r/20220131163224.708002-1-quentin.schulz@theobroma-systems.com Signed-off-by: Heiko Stuebner Signed-off-by: Greg Kroah-Hartman --- drivers/clk/rockchip/clk.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c index b7be7e1..bb8a844 100644 --- a/drivers/clk/rockchip/clk.c +++ b/drivers/clk/rockchip/clk.c @@ -180,6 +180,7 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate, unsigned long *m, unsigned long *n) { + struct clk_fractional_divider *fd = to_clk_fd(hw); unsigned long p_rate, p_parent_rate; struct clk_hw *p_parent; @@ -190,6 +191,8 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, *parent_rate = p_parent_rate; } + fd->flags |= CLK_FRAC_DIVIDER_POWER_OF_TWO_PS; + clk_fractional_divider_general_approximation(hw, rate, parent_rate, m, n); } -- 2.7.4