Re: [PATCH RESEND] iommu/of: Fix pci_request_acs() before enumerating PCI devices

[Greg Kroah-Hartman]

On Thu, Nov 07, 2024 at 01:29:15PM +0530, Pavankumar Kondeti wrote:
> From: Xingang Wang <wangxingang5@xxxxxxxxxx>
> 
> When booting with devicetree, the pci_request_acs() is called after the
> enumeration and initialization of PCI devices, thus the ACS is not
> enabled. And ACS should be enabled when IOMMU is detected for the
> PCI host bridge, so add check for IOMMU before probe of PCI host and call
> pci_request_acs() to make sure ACS will be enabled when enumerating PCI
> devices.
> 
> Fixes: 6bf6c24720d33 ("iommu/of: Request ACS from the PCI core when configuring IOMMU linkage")
> Signed-off-by: Xingang Wang <wangxingang5@xxxxxxxxxx>
> Signed-off-by: Pavankumar Kondeti <quic_pkondeti@xxxxxxxxxxx>
> ---
> Earlier this patch made it to linux-next but got dropped later as it
> broke PCI on ARM Juno R1 board. AFAICT, this issue is never root caused,
> so resending this patch to get attention again.
> 
> https://lore.kernel.org/all/1621566204-37456-1-git-send-email-wangxingang5@xxxxxxxxxx/

Please don't resend known-broken patches.  Please fix them up before
resending, otherwise we will just ignore this one as well as obviously
we can not take such a thing (nor should you want us to.)

thanks,

greg k-h