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

[Soeren Moch]

On 15.07.26 07:40, Manivannan Sadhasivam wrote:
> 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 at vger.kernel.org> # 7.0.x
>>>> Signed-off-by: Soeren Moch <smoch at web.de>
>>> Reviewed-by: Manivannan Sadhasivam <mani at kernel.org>
>>>
>>> @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
OK, I sent a v2:
https://lkml.org/lkml/2026/7/16/2092

Thanks,
Soeren