lkml.org 
[lkml]   [2017]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge
From
Date
On 20/04/17 09:20, Mason wrote:
> On 19/04/2017 13:19, Mason wrote:
>
>> My biggest problem is that tango_unmask() is never called.
>
> FTR, the missing incantation was:
> Explicitly calling tango_{mask/unmask/ack} from the corresponding msi_{mask/unmask/ack}

Using irq_chip_mask_parent and co, you mean?

> Marc, I have one nagging doubt, wrt splitting MSI line selection
> and MSI enable.
>
> tango_irq_domain_alloc : finds an available MSI 'j' to allocate
> tango_irq_domain_free : release MSI 'j'
> tango_unmask : enable MSI 'j'
> tango_mask : disable MSI 'j'
>
> Is the following scenario guaranteed to never happen?
>
> tango_irq_domain_alloc // alloc 0
> tango_irq_domain_free // free 0
> tango_irq_domain_alloc // alloc 0
> tango_unmask // enable 0
> tango_unmask // enable 0 = NOP
> tango_mask // disable 0
>
> In this theoretical scenario, we would be left with a non-functional
> MSI 0.

I'm not sure I get the example above, and what the various alloc/free
calls have to do with anything. If you have unbalanced
enable/disable_irq, you loose. Don't do that.

M.
--
Jazz is not dead. It just smells funny...

\
 
 \ /
  Last update: 2017-04-20 11:44    [W:0.137 / U:4.884 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site