Re: [PATCH 2/5] PCI: endpoint: Introduce 'epc_deinit' event and notify the EPF drivers

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Tue, Jun 11, 2024 at 05:06:40PM -0500, Bjorn Helgaas wrote:
> On Thu, Jun 06, 2024 at 12:56:35PM +0530, Manivannan Sadhasivam wrote:
> > As like the 'epc_init' event, that is used to signal the EPF drivers about
> > the EPC initialization, let's introduce 'epc_deinit' event that is used to
> > signal EPC deinitialization.
> > 
> > The EPC deinitialization applies only when any sort of fundamental reset
> > is supported by the endpoint controller as per the PCIe spec.
> > 
> > Reference: PCIe Base spec v5.0, sections 4.2.4.9.1 and 6.6.1.
> 
> PCIe r6.0, sec 4.2.5.9.1 and 6.6.1.
> 
> (Not 4.2.4.9.1, which no longer exists in r6.x)
> 

Ammended the commit in pci/endpoint, thanks!

- Mani

> > Currently, some EPC drivers like pcie-qcom-ep and pcie-tegra194 support
> > PERST# as the fundamental reset. So the 'deinit' event will be notified to
> > the EPF drivers when PERST# assert happens in the above mentioned EPC
> > drivers.
> > 
> > The EPF drivers, on receiving the event through the epc_deinit() callback
> > should reset the EPF state machine and also cleanup any configuration that
> > got affected by the fundamental reset like BAR, DMA etc...
> > 
> > This change also warrants skipping the cleanups in unbind() if already done
> > in epc_deinit().
> > 
> > Reviewed-by: Niklas Cassel <cassel@kernel.org>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

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