Re: [PATCH v2 0/9] PCI: rockchip: Fix RK3399 PCIe endpoint controller driver

[Damien Le Moal]

On 3/14/23 16:57, Rick Wertenbroek wrote:
> On Tue, Mar 14, 2023 at 1:02 AM Damien Le Moal
> <damien.lemoal@xxxxxxxxxxxxxxxxxx> wrote:
>>
>> On 2/14/23 23:08, Rick Wertenbroek wrote:
>>> This is a series of patches that fixes the PCIe endpoint controller driver
>>> for the Rockchip RK3399 SoC. The driver was introduced in
>>> cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller")
>>> The original driver had issues and would not allow for the RK3399 to
>>> operate in PCIe endpoint mode correctly. This patch series fixes that so
>>> that the PCIe core controller of the RK3399 SoC can now act as a PCIe
>>> endpoint. This is v2 of the patch series and addresses the concerns that
>>> were raised during the review of the first version.
>>
>> Rick,
>>
>> Are you going to send a rebased V3 soon ? I have a couple of additional
>> patches to add on top of your series...
>>
> 
> I'll try to send a V3 this week. The changes to V2 will be the issues
> raised and discussed on the V2 here in the mailing list with the additional
> code for removing the unsupported MSI-X capability list (was discussed
> in the mailing list as well).

Thanks.

Additional patch needed to avoid problems with this controller is that
we need to set ".align = 256" in the features. Otherwise, things do not
work well. This is because the ATU drops the low 8-bits of the PCI
addresses. It is a one liner patch, so feel free to add it to your series.

I also noticed random issues wich seem to be due to link-up timing... We
probably will need to implement a poll thread to detect and notify with
the linkup callback when we actually have the link established with the
host (see the dw-ep controller which does something similar).


From: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Date: Thu, 9 Mar 2023 16:37:24 +0900
Subject: [PATCH] PCI: rockchip: Set address alignment for endpoint mode

The address translation unit of the rockchip EP controller does not use
the lower 8 bits of a PCIe-space address to map local memory. Thus we
must set the align feature field to 256 to let the user know about this
constraint.

Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
---
 drivers/pci/controller/pcie-rockchip-ep.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c
b/drivers/pci/controller/pcie-rockchip-ep.c
index 12db9a9d92af..c6a23db84967 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -471,6 +471,7 @@ static const struct pci_epc_features
rockchip_pcie_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
 	.msix_capable = false,
+	.align = 256,
 };

 static const struct pci_epc_features*
-- 
2.39.2


-- 
Damien Le Moal
Western Digital Research