Hi Scott,
please see my comments inline.
On 06/15/2013 06:13 AM, Scott Wood wrote:
On 06/14/2013 02:15:59 AM, Minghuan Lian wrote:
1. Only MSIIR1 can index 16 MSI registers, but when using MSIIR1
the IRQs of a register are not continuous. for example, the first
register irq values are 0x0, 0x10, 0x20, 0x30 ... 0x1f0. So it
is hard to use 'msi-available-ranges' property to indicate the
available ranges and 'msi-available-ranges' property has been
removed from dts node, so this patch removes the related code.
2. Add 'msiregs' kernel parameter instead of 'msi-available-ranges'
functionality.
The reason we used a device tree property was because this is for
virtualization and AMP scenarios where this instance of Linux does not
own all of the MSI registers.
I don't see any reasonable way to partition an MPIC v4.3 MSI group --
but there are more groups, so it's not that bad. What's the use case
for this patch?
[Minghuan] I do not known any case about this patch. I add 'msiregs'
just for achieving "msi-available-ranges" functionality. I do not want
to remove partition functionality when updating to mpic4.3, although I
do not see virtualization and AMP cases on T4(KVM does not need this
functionality).
If you hope to keep 'msi-available-ranges' property for older mpic, can
I add 'msi-available-regs' property for mpic4.3.
Using 'msi-available-regs' to implement partition is similar to
'msi-available-ranges'. When considering the consistency,
'msi-available-regs' is better than msiregs.
-Scott
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