Messages in this thread | | | Date | Tue, 25 Jul 2023 10:16:04 +0530 | Subject | Re: [PATCH 1/1] PCI: qcom: Add early fixup to set the max payload size for IPQ9574 | From | Praveenkumar I <> |
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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@quicinc.com> >>>> --- >>> [...] >>> >>>> +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@nvidia.com/ > > - 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
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