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Date: Wed, 27 Mar 2024 10:41:39 +0100
From: Niklas Cassel <cassel@kernel.org>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
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Subject: Re: [PATCH v12 8/8] PCI: endpoint: Remove "core_init_notifier" flag
Message-ID: <ZgPp020vefFw3pGk@ryzen>
References: <20240327-pci-dbi-rework-v12-0-082625472414@linaro.org>
 <20240327-pci-dbi-rework-v12-8-082625472414@linaro.org>
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In-Reply-To: <20240327-pci-dbi-rework-v12-8-082625472414@linaro.org>

On Wed, Mar 27, 2024 at 02:43:37PM +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.
> 
> But this also requires the EPC core driver to deliver the notification
> after EPF driver bind. Because, the glue driver can send the notification
> before the EPF drivers bind() and in those cases the EPF drivers will miss
> the event. To accommodate this, EPC core is now caching the state of the
> EPC initialization in 'init_complete' flag and pci-ep-cfs driver sends the
> notification to EPF drivers based on that after each EPF driver bind.
> 
> Tested-by: Niklas Cassel <cassel@kernel.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---

Reviewed-by: Niklas Cassel <cassel@kernel.org>