From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Heiko Stuebner To: mturquette@baylibre.com, sboyd@codeaurora.org Cc: linux-clk@vger.kernel.org, linux-rockchip@lists.infradead.org, zhengxing@rock-chips.com, zhangqing@rock-chips.com, tomeu.vizoso@collabora.com, Heiko Stuebner Subject: [RFC PATCH 0/3] clk: attempt to keep requested rate on parent changes Date: Mon, 2 May 2016 18:36:19 +0200 Message-Id: <1462206982-10444-1-git-send-email-heiko@sntech.de> List-ID: I remember reading about people discussing that problem in the past, but haven't been able to find another approach to it yet [or I'm just blind as happens to often]. Our problem is the following clock structure: [anotherPLL] | ------ [div] ----- dclk_vop | [ vpll ] --------- hdmi_phy We need to set the vpll dynamically but still want to retain The other option that comes to mind, would be to have a clock-notifier, in the drm driver, but calling clk_set_rate from their looks like it shouldn't work due to the prepare mutex already being held. The whole thing is labeled RFC because while it works for us and solves the problem, I'm not sure if I'm overlooking some important aspect or am interferring with some other planned approach for that issue. Heiko Stuebner (3): clk: fix inconsistent use of req_rate clk: adjust clocks to their requested rate after parent changes clk: rockchip: make rk3399 vop dclks keep their rate on parent rate changes drivers/clk/clk.c | 37 +++++++++++++++++++++++++++++-------- drivers/clk/rockchip/clk-rk3399.c | 4 ++-- include/linux/clk-provider.h | 1 + 3 files changed, 32 insertions(+), 10 deletions(-) -- 2.8.0.rc3