Re: [PATCH] PCI: imx6: Keep Root Port MSI capability also for i.MX6Q

[Manivannan Sadhasivam]

On Wed, Jul 08, 2026 at 10:52:22AM +0200, Soeren Moch wrote:
> On 06.07.26 12:29, Manivannan Sadhasivam wrote:
> > On Mon, Apr 27, 2026 at 01:58:04PM +0200, Soeren Moch wrote:
> > > Also on the NXP i.MX6Q chipset MSIs from the endpoints won't be received by
> > > the iMSI-RX MSI controller if the Root Port MSI capability is disabled.
> > > 
> > > Even though the Root Port MSIs won't be received by the iMSI-RX controller
> > > due to design, this chipset has some weird hardware bug that prevents
> > > the endpoint MSIs from reaching when the Root Port MSI capability is
> > > disabled.
> > > 
> > > Hence, always keep the Root Port MSI capability for this chipset.
> > > 
> > > Note that by keeping Root Port MSI capability, Root Port MSIs such as AER,
> > > PME and others won't be received by default. So users need to use
> > > workarounds such as passing 'pcie_pme=nomsi' cmdline param.
> > > 
> > > Fixes: 3a4e8302e72f ("PCI: imx6: Keep Root Port MSI capability with iMSI-RX to work around hardware bug")
> > This is not the correct fixes tag. Correct one is:
> > f5cd8a929c825 ("PCI: dwc: Remove MSI/MSIX capability for Root Port if iMSI-RX is used as MSI controller")
> Thanks for the fix of the fixes tag!
> > > Cc: <stable@xxxxxxxxxxxxxxx> # 7.0.x
> > > Signed-off-by: Soeren Moch <smoch@xxxxxx>
> > Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> > 
> > @Bjorn: Can you merge this patch for 7.2-rcS with correct fixes tag?
> I can send a v2 of the patch if you prefer.
> 

That'll help.

- Mani

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