Re: [PATCH v4 01/17] PCI: dwc: Use the DMA-API to get the MSI address
From: Niklas Cassel
Date: Tue Nov 21 2017 - 07:18:27 EST
On 08/11/17 13:45, Joao Pinto wrote:
> Hello to all,
>
> Ãs 12:56 AM de 11/8/2017, Bjorn Helgaas escreveu:
>> On Fri, Nov 03, 2017 at 02:47:05PM +0100, Niklas Cassel wrote:
>>> Use the DMA-API to get the MSI address. This address will be written to
>>> our PCI config space and to the register which determines which AXI
>>> address the DWC IP will spoof for incoming MSI irqs.
>>>
>>> Since it is a PCIe endpoint device, rather than the CPU, that is supposed
>>> to write to the MSI address, the proper way to get the MSI address is by
>>> using the DMA API, not by using virt_to_phys().
>>>
>>> Using virt_to_phys() might work on some systems, but using the DMA API
>>> should work on all systems.
>>>
>>> This is essentially the same thing as allocating a buffer in a driver
>>> to which the endpoint will write to. To do this, we use the DMA API.
>>>
>>> Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx>
>>
>> I'm expecting Jingoo and/or Joao to chime in and ack the
>> DesignWare-related patches. I think all the others are in
>> pretty good shape.
>>
>>> ---
>>> drivers/pci/dwc/pcie-designware-host.c | 15 ++++++++++++---
>>> drivers/pci/dwc/pcie-designware.h | 3 ++-
>>> 2 files changed, 14 insertions(+), 4 deletions(-)
>>> ...
>
> Let me test this patch-set in my setup first!
> I will give feedback until Friday.
>
Hello Joao,
did you manage to find any time to test the designware
related patches?
If not, I posted a V5 yesterday, so in case you are still
planning on testing them, could you please test V5 instead?
Best regards,
Niklas