mainlining shenanigans
99652a469d
The orphan clocks reparents should migrate any existing count from the orphan clock to its new acestor clocks, otherwise we may have inconsistent counts in the tree and end-up with gated critical clocks Assuming we have two clocks, A and B. * Clock A has CLK_IS_CRITICAL flag set. * Clock B is an ancestor of A which can gate. Clock B gate is left enabled by the bootloader. Step 1: Clock A is registered. Since it is a critical clock, it is enabled. The clock being still an orphan, no parent are enabled. Step 2: Clock B is registered and reparented to clock A (potentially through several other clocks). We are now in situation where the enable count of clock A is 1 while the enable count of its ancestors is 0, which is not good. Step 3: in lateinit, clk_disable_unused() is called, the enable_count of clock B being 0, clock B is gated and and critical clock A actually gets disabled. This situation was found while adding fdiv_clk gates to the meson8b platform. These clocks parent clk81 critical clock, which is the mother of all peripheral clocks in this system. Because of the issue described here, the system is crashing when clk_disable_unused() is called. The situation is solved by reverting commit |
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| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.