On 06/17/2013 10:10:17 PM, Lian Minghuan-b31939 wrote:
Hi Scott,
please see my comments inline.
On 06/18/2013 08:18 AM, Scott Wood wrote:
On 06/17/2013 12:36:50 AM, Lian Minghuan-b31939 wrote:
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).
Such functionality does not work on mpic v4.3. There are
conflicting requirements of contiguous MSIs (because PCI devices can
use them that way) and the inability to partition a single register
(because they all go to the same MPIC interrupt).
Keep msi-available-ranges as is for older hardware, and just ignore
it (with a warning printed) if it's present on MPIC v4.3.
[Minghuan] Thanks for your guidance.
But 'msireg' should be remained or removed?
Removed.
-Scott
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
