Re: [RFT PATCH v3 12/27] of/address: Add infrastructure to declare MMIO as non-posted

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Mar 8, 2021 at 2:56 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>
> On Mon, Mar 8, 2021 at 10:14 PM Rob Herring <robh@xxxxxxxxxx> wrote:
> > On Mon, Mar 08, 2021 at 09:29:54PM +0100, Arnd Bergmann wrote:
> > > On Mon, Mar 8, 2021 at 4:56 PM Rob Herring <robh@xxxxxxxxxx> wrote:
> >
> > Let's just stick with 'nonposted-mmio', but drop 'posted-mmio'. I'd
> > rather know if and when we need 'posted-mmio'. It does need to be added
> > to the DT spec[1] and schema[2] though (GH PRs are fine for both).
>
> I think the reason for having "posted-mmio" is that you cannot properly
> define the PCI host controller nodes on the M1 without that: Since
> nonposted-mmio applies to all child nodes, this would mean the PCI
> memory space gets declared as nonposted by the DT, but the hardware
> requires it to be mapped as posted.

I don't think so. PCI devices wouldn't use any of the code paths in
this patch. They would map their memory space with plain ioremap()
which is posted.

Rob



[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux