On 9/10/2022 1:20 AM, Bjorn Helgaas wrote:
On Fri, Sep 09, 2022 at 02:14:41PM +0530, Krishna chaitanya chundru wrote:
Some specific devices are taking time to settle the link in L1ss.
So added a retry logic before returning from the suspend op.
"L1ss" is not a state. If you mean "L1.1" or "L1.2", say that. Also
in code comments below.
Yes L1ss means L1.2 and L1.2 We will update it next patch
s/So added a/Add/
What are these specific devices? Is this a qcom controller defect?
An endpoint defect that should be addressed via some kind of generic
quirk?
This is depending up on the endpoint devices and it varies to device to
device.
We are thinking this is not a defect if there is some traffic in the
link the link will
not go to L1ss .
Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-qcom.c | 36 +++++++++++++++++++++++-----------
1 file changed, 25 insertions(+), 11 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 6e04d0d..15c2067 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1809,26 +1809,40 @@ static int qcom_pcie_probe(struct platform_device *pdev)
static int __maybe_unused qcom_pcie_pm_suspend(struct qcom_pcie *pcie)
{
u32 val;
+ ktime_t timeout, start;
struct dw_pcie *pci = pcie->pci;
struct device *dev = pci->dev;
if (!pcie->cfg->supports_system_suspend)
return 0;
- /* if the link is not active turn off clocks */
- if (!dw_pcie_link_up(pci)) {
- dev_info(dev, "Link is not active\n");
- goto suspend;
- }
+ start = ktime_get();
+ /* Wait max 200 ms */
+ timeout = ktime_add_ms(start, 200);
- /* if the link is not in l1ss don't turn off clocks */
- val = readl(pcie->parf + PCIE20_PARF_PM_STTS);
- if (!(val & PCIE20_PARF_PM_STTS_LINKST_IN_L1SUB)) {
- dev_warn(dev, "Link is not in L1ss\n");
- return 0;
+ while (1) {
+
+ if (!dw_pcie_link_up(pci)) {
+ dev_warn(dev, "Link is not active\n");
+ break;
+ }
+
+ /* if the link is not in l1ss don't turn off clocks */
+ val = readl(pcie->parf + PCIE20_PARF_PM_STTS);
+ if ((val & PCIE20_PARF_PM_STTS_LINKST_IN_L1SUB)) {
+ dev_dbg(dev, "Link enters L1ss after %d ms\n",
+ ktime_to_ms(ktime_get() - start));
+ break;
+ }
+
+ if (ktime_after(ktime_get(), timeout)) {
+ dev_warn(dev, "Link is not in L1ss\n");
+ return 0;
+ }
+
+ udelay(1000);
}
-suspend:
if (pcie->cfg->ops->suspend)
pcie->cfg->ops->suspend(pcie);
--
2.7.4
