Messages in this thread | | | Subject | Re: [PATCH v1] clk: Export __clk_lookup() | From | "elaine.zhang" <> | Date | Thu, 23 Jul 2020 09:49:35 +0800 |
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在 2020/7/23 上午9:42, elaine.zhang 写道: > > 在 2020/7/23 上午8:51, Stephen Boyd 写道: >> Quoting Heiko Stuebner (2020-07-22 11:26:50) >>> Hi Elaine, >>> >>> Am Mittwoch, 22. Juli 2020, 04:32:30 CEST schrieb Elaine Zhang: >>>> Export __clk_lookup() to support user built as module. >>>> >>>> ERROR: >>>> drivers/clk/rockchip/clk.ko: In function >>>> `rockchip_clk_protect_critical': >>>> drivers/clk/rockchip/clk.c:741: >>>> undefined reference to `__clk_lookup' >>> can you elaborate a bit more on why this would be needed? >>> >>> Because right now the Rockchip clocks are of course built into >>> the main kernel image (especially due to them being needed during early >>> boot) and __clk_lookup actually is a pretty deep part of the clock- >>> framework itself, as probably also denoted by the "__" in the function >>> name. >>> >> Can you stop using __clk_lookup()? The plan is to remove it. > > Rk use __clk_lookup() as: > > drivers/clk/rockchip/clk.c > > void __init rockchip_clk_protect_critical(const char *const clocks[], > int nclocks) > { > int i; > > /* Protect the clocks that needs to stay on */ > for (i = 0; i < nclocks; i++) { > struct clk *clk = __clk_lookup(clocks[i]); > > if (clk) > clk_prepare_enable(clk); > } > } > e.g: > > drivers/clk/rockchip/clk-rk3328.c > > static const char *const rk3328_critical_clocks[] __initconst = { > "aclk_bus", > "aclk_bus_niu", > "pclk_bus", > "pclk_bus_niu", > "hclk_bus", > "hclk_bus_niu", > "aclk_peri", > ............ > > }; > > If have plan to remove the __clk_lookup, I need to replace the > rockchip_clk_protect_critical, and use the flag CLK_IS_CRITICAL.(but > use flag CLK_IS_CRITICAL, the enable count is always "0") Use the CLK_IS_CRITICAL, there is no guarantee that the parent clk is enabled, So the flag CLK_IS_CRITICAL need to be added to all special clks according to the clk tree. > >> >>
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