On 7/24/2023 7:39 PM, Manivannan Sadhasivam wrote:
On Mon, Jul 24, 2023 at 06:38:55PM +0530, Manivannan Sadhasivam wrote:
On Mon, Jul 24, 2023 at 02:53:37PM +0200, Konrad Dybcio wrote:
On 24.07.2023 14:47, Praveenkumar I wrote:
Set 256 bytes as payload size for IPQ9574 via early fixup. This allows
PCIe RC to use the max payload size when a capable link partner is
connected.
Signed-off-by: Praveenkumar I <quic_ipkumar@xxxxxxxxxxx>
---
[...]
+static void qcom_fixup_mps_256(struct pci_dev *dev)
+{
+ pcie_set_mps(dev, 256);
Looks like setting "dev->pcie_mpss = 1" here would make the PCIe generic
code take care of this.
Right, also this setting should not be PCI-PCI bridge specific but rather
controller specific.
Wait, have you tested this patch with PCIe devices having MPS < 256 i.e.,
default 128?
Take a look at this discussion: https://lore.kernel.org/all/20230608093652.1409485-1-vidyas@xxxxxxxxxx/
- Mani
Yes, tested this patch with PCIe devices having default 128 and RC is
falling back to 128 when pci device is added.
This is handled inside pci_configure_mps().
/ mpss = 128 << dev->pcie_mpss;/
/ if (mpss < p_mps && pci_pcie_type(bridge) ==
PCI_EXP_TYPE_ROOT_PORT) {/
/ pcie_set_mps(bridge, mpss);/
/ pci_info(dev, "Upstream bridge's Max Payload Size set
to %d (was %d, max %d)\n",/
/ mpss, p_mps, 128 << bridge->pcie_mpss);/
/ p_mps = pcie_get_mps(bridge);/
/ }/
//
Also getting the below print,
/[ 2.011963] pci 0003:01:00.0: Upstream bridge's Max Payload Size set
to 128 (was 256, max 256)/
- Mani
Konrad
--
மணிவண்ணன் சதாசிவம்
--
Thanks,
Praveenkumar
