Re: (subset) [PATCH v8 0/5] PCI: dwc: Add ECAM support with iATU configuration

From: Krishna Chaitanya Chundru

Date: Wed Nov 12 2025 - 22:57:46 EST



On 11/10/2025 11:51 PM, Bjorn Andersson wrote:
On Tue, Oct 28, 2025 at 11:12:23PM +0530, Krishna Chaitanya Chundru wrote:
On 10/28/2025 4:07 AM, Bjorn Andersson wrote:
On Thu, 28 Aug 2025 13:04:21 +0530, Krishna Chaitanya Chundru wrote:
The current implementation requires iATU for every configuration
space access which increases latency & cpu utilization.

Designware databook 5.20a, section 3.10.10.3 says about CFG Shift Feature,
which shifts/maps the BDF (bits [31:16] of the third header DWORD, which
would be matched against the Base and Limit addresses) of the incoming
CfgRd0/CfgWr0 down to bits[27:12]of the translated address.

[...]
Applied, thanks!

[1/5] arm64: dts: qcom: sc7280: Increase config size to 256MB for ECAM feature
commit: 03e928442d469f7d8dafc549638730647202d9ce
Hi Bjorn,

Can you revert this change, this is regression due to this series due to
that we have change the logic,
How is that possible? This is patch 1 in the series, by definition it
doesn't have any outstanding dependencies.
The regression is due to the drivers changes on non qcom platforms.

- Krishna Chaitanya.
I've reverted the change.

Regards,
Bjorn

we need to update the dtsi accordingly, I will send a separate for all
controllers to enable this ECAM feature.

- Krishna Chaitanya.


Best regards,