On Wed, 6 May 2020 20:42:35 +0300 <[email protected]> wrote:
> From: Serge Semin <[email protected]> > > Loops-per-jiffies is a special number which represents a number of > noop-loop cycles per CPU-scheduler quantum - jiffies. As you > understand aside from CPU-specific implementation it depends on > the CPU frequency. So when a platform has the CPU frequency fixed, > we have no problem and the current udelay interface will work > just fine. But as soon as CPU-freq driver is enabled and the cores > frequency changes, we'll end up with distorted udelay's. In order > to fix this we have to accordinly adjust the per-CPU udelay_val > (the same as the global loops_per_jiffy) number. This can be done > in the CPU-freq transition event handler. We subscribe to that event > in the MIPS arch time-inititalization method. > > Co-developed-by: Alexey Malahov <[email protected]> > Signed-off-by: Alexey Malahov <[email protected]> > Signed-off-by: Serge Semin <[email protected]> > Cc: Thomas Bogendoerfer <[email protected]> > Cc: Paul Burton <[email protected]> > Cc: Ralf Baechle <[email protected]> > Cc: Arnd Bergmann <[email protected]> > Cc: Rob Herring <[email protected]> > Cc: [email protected] > Cc: [email protected] Reviewed-by: Jiaxun Yang <[email protected]> That have been absent in MIPS kernel so long! Thanks. > --- [...] --- Jiaxun Yang
