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Date: Fri, 8 Mar 2024 15:14:04 +0530
From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Niklas Cassel <cassel@kernel.org>
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Subject: Re: [PATCH v9 07/10] PCI: dwc: ep: Remove "core_init_notifier" flag
Message-ID: <20240308094404.GF3789@thinkpad>
References: <20240304-pci-dbi-rework-v9-0-29d433d99cda@linaro.org>
 <20240304-pci-dbi-rework-v9-7-29d433d99cda@linaro.org>
 <Zeos8kVxgchH9veF@ryzen>
 <20240308053829.GC3789@thinkpad>
 <ZerQxxfUvFm2MjqV@ryzen>
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On Fri, Mar 08, 2024 at 09:48:07AM +0100, Niklas Cassel wrote:
> On Fri, Mar 08, 2024 at 11:08:29AM +0530, Manivannan Sadhasivam wrote:
> > On Thu, Mar 07, 2024 at 10:09:06PM +0100, Niklas Cassel wrote:
> > > On Mon, Mar 04, 2024 at 02:52:19PM +0530, Manivannan Sadhasivam wrote:
> > > > "core_init_notifier" flag is set by the glue drivers requiring refclk from
> > > > the host to complete the DWC core initialization. Also, those drivers will
> > > > send a notification to the EPF drivers once the initialization is fully
> > > > completed using the pci_epc_init_notify() API. Only then, the EPF drivers
> > > > will start functioning.
> > > > 
> > > > For the rest of the drivers generating refclk locally, EPF drivers will
> > > > start functioning post binding with them. EPF drivers rely on the
> > > > 'core_init_notifier' flag to differentiate between the drivers.
> > > > Unfortunately, this creates two different flows for the EPF drivers.
> > > > 
> > > > So to avoid that, let's get rid of the "core_init_notifier" flag and follow
> > > > a single initialization flow for the EPF drivers. This is done by calling
> > > > the dw_pcie_ep_init_notify() from all glue drivers after the completion of
> > > > dw_pcie_ep_init_registers() API. This will allow all the glue drivers to
> > > > send the notification to the EPF drivers once the initialization is fully
> > > > completed.
> > > > 
> > > > Only difference here is that, the drivers requiring refclk from host will
> > > > send the notification once refclk is received, while others will send it
> > > > during probe time itself.
> > > > 
> > > > Reviewed-by: Frank Li <Frank.Li@nxp.com>
> > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > > > ---
> > > 
> > > You have removed the .core_init_notifier from EPC drivers,
> > > but the callback in EPF drivers is still called .core_init.
> > > 
> > > Yes, this was a confusing name even before this patch, but
> > > after this patch, it is probably even worse :)
> > > 
> > > The callback should be named from the perspective of EPF drivers IMO.
> > > .core_init sounds like a EPF driver should initialize the core.
> > > (But that is of course done by the EPC driver.)
> > > 
> > > The .link_up() callback name is better, the EPF driver is informed
> > > that the link is up.
> > > 
> > > Perhaps we could rename .core_init to .core_up ?
> > > 
> > > It tells the EPF drivers that the core is now up.
> > > (And the EPF driver can configure the BARs.)
> > > 
> > 
> > I don't disagree :) I thought about it but then decided to not extend the scope
> > of this series further. So saved that for next series.
> > 
> > But yeah, it is good to clean it up here itself.
> 
> If you intend to create a .core_deinit or .core_down (or whatever name
> you decide on), perhaps it is better to leave this cleanup to be part
> of that same series?
> 

I already added a patch. So let's do it here itself :)

- Mani

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