On Wed, 2015-01-21 at 11:35 +0200, Purcareata Bogdan wrote:
> On 14.01.2015 19:58, Scott Wood wrote:
> > On Wed, 2015-01-14 at 11:57 +, Bogdan Purcareata wrote:
> >> The readback is necessary in order to handle PCI posted
> >> writes,
> >
> > That is unclear.
>
> I'm going to try an venture a
On 14.01.2015 19:58, Scott Wood wrote:
On Wed, 2015-01-14 at 11:57 +, Bogdan Purcareata wrote:
The readback is necessary in order to handle PCI posted
writes,
That is unclear.
I'm going to try an venture a different explanation here.
I found a good explanation in Writing PCI Drivers [1]
The readback is necessary in order to handle PCI posted
writes, or when the MPIC is handling interrupts in a loop
(ppc_md.get_irq). Newer MPIC versions don't require this
readback. Leave the option configurable using a device
tree entry.
This saves a MMIO trap per interrupt.
Signed-off-by: Scott
On Wed, 2015-01-14 at 11:57 +, Bogdan Purcareata wrote:
> The readback is necessary in order to handle PCI posted
> writes,
That is unclear.
> or when the MPIC is handling interrupts in a loop
> (ppc_md.get_irq).
I'm questioning this one as well -- if reading WHOAMI is sufficient to
sync wi
