[PATCH] clk: aspeed: Support HPLL strapping on ast2400

Joel Stanley joel at jms.id.au
Wed Jul 11 15:53:52 AEST 2018

Hi Stephen,

On 7 July 2018 at 03:55, Stephen Boyd <sboyd at kernel.org> wrote:
> Quoting Joel Stanley (2018-06-28 16:15:40)
>> The HPLL can be configured through a register (SCU24), however some
>> platforms chose to configure it through the strapping settings and do
>> not use the register. This was not noticed as the logic for bit 18 in
>> SCU24 was confused: set means programmed, but the driver read it as set
>> means strapped.
>> This gives us the correct HPLL value on Palmetto systems, from which
>> most of the peripheral clocks are generated.
>> Fixes: 5eda5d79e4be ("clk: Add clock driver for ASPEED BMC SoCs")
>> Cc: stable at vger.kernel.org # v4.15
>> Reviewed-by: Cédric Le Goater <clg at kaod.org>
>> Signed-off-by: Joel Stanley <joel at jms.id.au>
>> ---
> Do you want this merged for -rc5? It sounds like on some systems this is
> a problem, but I don't know if these systems are supposed to work yet or
> not, so priority of this fix is not easy for me to understand.

Sure, some more background:

We did not notice this until we attempted to use the clock for the mtd
driver. However, this clock is used for the kernel clocksource, so eg.
sleep 1 takes two seconds to complete. This affects all of the systems
I have access to.

I suggest we merge for4.18, and keep the cc: stable so it can be
backported to the stable trees.



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