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    SubjectRe: [PATCH v3 09/11] serial: 8250_lpss: move Quark code from PCI driver
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    On Wed, 2016-05-04 at 14:20 +0300, Andy Shevchenko wrote:
    > On Wed, 2016-05-04 at 12:01 +0100, Bryan O'Donoghue wrote:
    > > On Wed, 2016-05-04 at 13:03 +0300, Andy Shevchenko wrote:
    > > >
    > > > On Wed, May 4, 2016 at 12:51 PM, Bryan O'Donoghue
    > > > <pure.logic@nexus-software.ie> wrote:
    > > > >
    > > > > The default may be set to SERIAL_8250 but, without the QRK
    > > > > specific
    > > > > entry in 8250_pci.c you won't get console output.
    >
    > That's, by the way, not true.

    Since when ? We don't have an I/O bar so mapping the MMIO bar @ the
    right register width is required.

    >
    > > > >
    > > > > So if you are going to remove the QRK entry from 8250_pci.c and
    > > > > stuff
    > > > > it into 8250_lpss.c then 8250_lpss needs to be selected by
    > > > > CONFIG_SERIAL_8250_PCI.
    > > > Why?!
    > > >
    > > > Now it should be enough to have SERIAL_8250 set to non-n to have
    > > > 8250_lpss compiled.
    > > > Can you check it?
    > > I'm sure that's true.
    > >
    > > My point to you is that - its a highly non-intuitive thing to do on
    > > a
    > > reading of the datasheet for this part.
    > >
    > > LPSS is, ostensibly at least, for passing processor resources via
    > > APCI.
    > >
    > > If you look at a QRK datasheet it says "enumerate all this stuff
    > > via
    > > PCI" - there's not a single mention of LPSS. Its reasonable,
    > > correct
    > > and currently required for QRK to set CONFIG_8250_PCI.
    >
    > User has no such item even visible until enable CONFIG_EXPERT.
    >
    > Heikki sent an answer to you (and to the list, but by some reason
    > it's
    > not yet there) an hour ago.
    >
    > >
    > > To move away from a valid/standard PCI probe routine into a new
    > > special
    > > LPSS/PCI shim (which the hardware doesn't actually mandate) I do
    > > think
    > > you should to setup the dependency CONFIG_8250_PCI =>
    > > CONFIG_8250_LPSS.
    >
    > No, this is what we try avoiding, thus it will not happen.
    >
    > If user selects CONFIG_SERIAL_8250_PCI, the CONFIG_SERIAL_8250_LPSS
    > will
    > be selected as well since it has same dependencies.

    Hmm. I think what you mean to say is that a user (expert or not)
    *would* select SERIAL_8250_LPSS since (at least in your branch
    09c4268121a39eb3973823dd9225b650df726f67) both options may be
    individually selected/deselected.


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