Messages in this thread | | | Subject | Re: [V2] [PATCH] clk: zynqmp: pll: add set_pll_mode to check condition in zynqmp_pll_enable | From | Stephen Boyd <> | Date | Wed, 31 Mar 2021 18:49:09 -0700 |
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Quoting quanyang.wang@windriver.com (2021-03-30 05:17:01) > From: Quanyang Wang <quanyang.wang@windriver.com> > > If there is a IOCTL_SET_PLL_FRAC_MODE request sent to ATF ever, > we shouldn't skip invoking PM_CLOCK_ENABLE fn even though this > pll has been enabled. In ATF implementation, it will only assign > the mode to the variable (struct pm_pll *)pll->mode when handling > IOCTL_SET_PLL_FRAC_MODE call. Invoking PM_CLOCK_ENABLE can force > ATF send request to PWU to set the pll mode to PLL's register. > > There is a scenario that happens in enabling VPLL_INT(clk_id:96): > 1) VPLL_INT has been enabled during booting. > 2) A driver calls clk_set_rate and according to the rate, the VPLL_INT > should be set to FRAC mode. Then zynqmp_pll_set_mode is called > to pass IOCTL_SET_PLL_FRAC_MODE to ATF. Note that at this point > ATF just stores the mode to a variable. > 3) This driver calls clk_prepare_enable and zynqmp_pll_enable is > called to try to enable VPLL_INT pll. Because of 1), the function > zynqmp_pll_enable just returns without doing anything after checking > that this pll has been enabled. > > In the scenario above, the pll mode of VPLL_INT will never be set > successfully. So adding set_pll_mode to check condition to fix it. > > Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com> > Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > ---
Any Fixes tag?
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