Re: [PATCH v2] PCI: imx6: Correct the epc_features of i.MX8M chips

[Bjorn Helgaas <helgaas@kernel.org>]

On Tue, Jul 08, 2025 at 07:34:57AM +0000, Hongxing Zhu wrote:
> > -----Original Message-----
> > From: Bjorn Helgaas <helgaas@kernel.org>
> ...
> > On Tue, Jun 17, 2025 at 03:34:41PM +0800, Richard Zhu wrote:
> > > i.MX8MQ PCIes have three 64-bit BAR0/2/4 capable and
> > > programmable BARs.  But i.MX8MM and i.MX8MP PCIes only have
> > > BAR0/BAR2 64bit programmable BARs, and one 256 bytes size fixed
> > > BAR4.
> > >
> > > Correct the epc_features for i.MX8MM and i.MX8MP PCIes here.
> > > i.MX8MQ is the same as i.MX8QXP, so set i.MX8MQ's epc_features
> > > to imx8q_pcie_epc_features.
> > >
> > > Fixes: 75c2f26da03f ("PCI: imx6: Add i.MX PCIe EP mode support")
> > > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > > Reviewed-by: Frank Li <Frank.Li@nxp.com>
> > 
> > "Correct the epc_features" doesn't include any specific
> > information, and it's hard to extract the changes for a device
> > from the commit log.
> > 
> > This is really two fixes that should be separated so the commit
> > logs can be specific:
>
> Yes, it's right.
> Since it's just one line change for i.MX8MQ. So, I combine the changes into
> this commit for i.MX8M chips.

I want to split them to make it easy for users to understand which
changes are relevant to them.  E.g., I have an i.MX8MQ system; do I
need this change and what does it mean for me?  Is it going to fix a
problem I've been seeing?

> >   - For IMX8MQ_EP, use imx8q_pcie_epc_features (64-bit BARs 0, 2, 4)
> >     instead of imx8m_pcie_epc_features (64-bit BARs 0, 2).
> > 
> >   - For IMX8MM_EP and IMX8MP_EP, add fixed 256-byte BAR 4 in
> >     imx8m_pcie_epc_features.