On Thu, Jul 26, 2018 at 05:24:09PM +0200, Neil Armstrong wrote:
> Hi Stable Team,
>
> On 13/06/2018 14:20, Neil Armstrong wrote:
> > On Amlogic Meson GXBB & GXL platforms, the SCPI Cortex-M4 Co-Processor
> > seems to be dependent on the FCLK_DIV2 to be operationnal.
> >
> > The issue occured since v4.17-rc1 by freezing the kernel boot when
> > the 'schedutil' cpufreq governor was selected as default :
> >
> > [ 12.071837] scpi_protocol scpi: SCP Protocol 0.0 Firmware 0.0.0 version
> > domain-0 init dvfs: 4
> > [ 12.087757] hctosys: unable to open rtc device (rtc0)
> > [ 12.087907] cfg80211: Loading compiled-in X.509 certificates for regulatory database
> > [ 12.102241] cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
> >
> > But when disabling the MMC driver, the boot finished but cpufreq failed to
> > change the CPU frequency :
> >
> > [ 12.153045] cpufreq: __target_index: Failed to change cpu frequency: -5
> >
> > A bisect between v4.16 and v4.16-rc1 gave the 05f814402d61 commit to be
> > the first bad commit.
> > This commit added support for the missing clock gates before the fixed PLL
> > fixed dividers (FCLK_DIVx) and the clock framework basically disabled
> > all the unused fixed dividers, thus disabled a critical clock path for
> > the SCPI Co-Processor.
> >
> > This patch simply sets the FCLK_DIV2 gate as critical to ensure
> > nobody can disable it.
> >
> > Fixes: 05f814402d61 ("clk: meson: add fdiv clock gates")
> > Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
>
>
> This patch hit linux master with commit id c987ac6f1f088663b6dad39281071aeb31d450a8
>
> Could this be backported to the next 4.17 stable release ?
Now queued up, thanks,
greg k-h
