Re: [PATCH v8 3/7] PCI: qcom: Add ICC bandwidth vote for CPU to PCIe path
From: Krishna Chaitanya Chundru
Date: Fri Apr 05 2024 - 06:16:45 EST
On 4/5/2024 1:59 PM, Manivannan Sadhasivam wrote:
On Tue, Mar 05, 2024 at 04:23:21PM +0530, Krishna Chaitanya Chundru wrote:
On 3/4/2024 11:11 PM, Manivannan Sadhasivam wrote:
On Sat, Mar 02, 2024 at 09:29:57AM +0530, Krishna chaitanya chundru wrote:
To access PCIe registers, PCIe BAR space, config space the CPU-PCIe
ICC (interconnect consumers) path should be voted otherwise it may
lead to NoC (Network on chip) timeout. We are surviving because of
other driver vote for this path.
As there is less access on this path compared to PCIe to mem path
add minimum vote i.e 1KBps bandwidth always.
Please add the info that 1KBps is what shared by the HW team.
Ack to all the comments
When suspending, disable this path after register space access
is done.
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-qcom.c | 38 ++++++++++++++++++++++++++++++++--
1 file changed, 36 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 10f2d0bb86be..a0266bfe71f1 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
[...]
+ ret = icc_disable(pcie->icc_cpu);
+ if (ret) {
+ dev_err(dev, "failed to disable icc path of cpu-pcie: %d\n", ret);
"CPU-PCIe"
+ if (pcie->suspended) {
+ qcom_pcie_host_init(&pcie->pci->pp);
Interesting. So if icc_disable() fails, can the IP continue to function?
As the ICC already enable before icc_disable() fails, the IP should work.
If icc_disable() fails, then most likely something is wrong with RPMh. How can
the IP continue to work in that case?
Ok then I will log the error and return here
- Krishna Chaitanya.
- Mani