[PATCH v3 3/6] PCI: imx6: Workaround i.MX95 PCIe may not exit L23 ready

[Hongxing Zhu]

> -----Original Message-----
> From: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
> Sent: 2025年4月2日 15:08
> To: Hongxing Zhu <hongxing.zhu at nxp.com>
> Cc: Frank Li <frank.li at nxp.com>; l.stach at pengutronix.de; lpieralisi at kernel.org;
> kw at linux.com; robh at kernel.org; bhelgaas at google.com;
> shawnguo at kernel.org; s.hauer at pengutronix.de; kernel at pengutronix.de;
> festevam at gmail.com; linux-pci at vger.kernel.org;
> linux-arm-kernel at lists.infradead.org; imx at lists.linux.dev;
> linux-kernel at vger.kernel.org
> Subject: Re: [PATCH v3 3/6] PCI: imx6: Workaround i.MX95 PCIe may not exit L23
> ready
> 
> On Fri, Mar 28, 2025 at 11:02:10AM +0800, Richard Zhu wrote:
> > ERR051624: The Controller Without Vaux Cannot Exit L23 Ready Through
> > Beacon or PERST# De-assertion
> 
> Is it possible to share the link to the erratum?
> 
Sorry, the erratum document isn't ready to be published yet.
> >
> > When the auxiliary power is not available, the controller cannot exit
> > from
> > L23 Ready with beacon or PERST# de-assertion when main power is not
> > removed.
> >
> 
> I don't understand how the presence of Vaux affects the controller. Same goes
> for PERST# deassertion. How does that relate to Vaux? Is this erratum for a
> specific endpoint behavior?
IMHO I don't know the exact details of the power supplies in this IP design.
Refer to my guess , maybe the beacon detect or wake-up logic in designs is
 relied on the status of SYS_AUX_PWR_DET signals in this case.

Best Regards
Richard Zhu
> 
> - Mani
> 
> --
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