Re: [PATCH] arm64: dts: msm8916: Move smem below hwlock

From: Srinivas Kandagatla
Date: Tue Feb 23 2016 - 14:28:44 EST




On 23/02/16 18:47, Georgi Djakov wrote:
On 23.02.16 Ð. 19:29, Srinivas Kandagatla wrote:


On 23/02/16 17:21, Georgi Djakov wrote:
When the SMEM is probed it defers as it depends on the hardware lock, which
is not available yet. But the SMD bus and RPM regulators and clocks depend
on SMEM and they defer too. The problem with this is that the order of
registering the devices is not optimal and also we may end with messed
up serial console as the RPM clocks are not registered yet..
I noticed the same issue but was wondering why would we end up with messed up serial console?

Could you add more details on why serial console is messed up?

I thought, serial driver has nothing to do with the rpm clocks directly!


If we don't have the rpm clocks registered, the uart clock is an orphan
and when clk_get_rate() is called on orphan clocks it returns 0 as rate.
Shouldn't the actual uart clk provider registration fail/defer probe due to missing parent in this case?

--srini
In our case the msm_serial driver calls clk_get_rate() and gets 0 rate
as the parent rpm clock has not registered yet. The result is that the
baudrate is set incorrectly.

BR,
Georgi