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[ Upstream commit394cdb69a3] 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. Fixes:3fde0e16d0("drivers: clk: Add ZynqMP clock driver") Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com> Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Link: https://lore.kernel.org/r/20210406153131.601701-1-quanyang.wang@windriver.com Signed-off-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.