On 4/2/20 4:34 AM, Simon Glass wrote:
Hi,
On Tue, 31 Mar 2020 at 20:33, Ang, Chee Hong chee.hong.ang@intel.com
wrote:
Hi Marek,
On Wed, 11 Mar 2020 at 05:55, Marek Vasut marex@denx.de wrote:
On 3/11/20 12:50 PM, Simon Glass wrote:
Hi,
Hi,
On Mon, 9 Mar 2020 at 02:22, chee.hong.ang@intel.com wrote: > > From: Chee Hong Ang chee.hong.ang@intel.com > > This commit (82de42fa14682d408da935adfb0f935354c5008f) calls > child's > ofdata_to_platdata() method before the parent is probed in dm core. > This has caused the driver no longer able to get the correct > parent clock's register base in the ofdata_to_platdata() method > because the parent clocks will only be probed after the child's
ofdata_to_platdata().
> To resolve this, the clock parent's register base will only be > retrieved by the child in probe() method instead of ofdata_to_platdata().
I think one thing that is going on here is that DM allows ofdata to be read for a device before its parent devices have been read, but it requires that parent devices be probed before their children.
This seems wrong. The clock driver should be able to instantiate devices and read their ofdata without probing them. That is one of the core design principles of the DM.
That's a different question. Yes you can read ofdata without probing a
device.
That's why we have two methods.
The point I am making is that at present there is no requirement that a parent's ofdata be read before a child's ofdata is read. But there is a requirement that a parent be probed before a child is probed.
The idea is that it should be possible to read the ofdata for a node without needing to have done so for parents. But perhaps this assumption is too brave?
Why is it brave ? That's how it always was, the DT is already there, so why wouldn't you be able to read it.
That was my thinking too. But we are finding in a few situations that the child's ofdata depends on the parent's. For example, the parent may have a base address, or a range mapping, or something else that is needed for the child to correctly get its base address, etc.
I suspect we could change this, so that device_ofdata_to_platdata() first calls itself on its parent.
I can think of various reasons why this change might be desirable.
I think this is how it worked before already.
Well effectively, yes, because ofdata and probe were joined together.
Simon, do you have plan to fix this DM core issue ?
I'm not sure it definitely should be changed. But I'll do a patch and see how it looks.
Do I understand it correctly that the patch 82de42fa14682d408da935adfb0f935354c5008f actually completely breaks SoCFPGA ? Then I would say this is a release blocker ?
Yes. A10 SPL won't boot at all. It crashes during the clock manager setup.