From d45736b5984954da71292d858f277bac9c70cd2e Mon Sep 17 00:00:00 2001 From: Shashank Babu Chinta Venkata Date: Wed, 11 Sep 2024 20:56:28 +0530 Subject: PCI: qcom: Add equalization settings for 16.0 GT/s MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During high data transmission rates such as 16.0 GT/s, there is an increased risk of signal loss due to poor channel quality and interference. This can impact receiver's ability to capture signals accurately. Hence, as signal compensation is achieved through appropriate lane equalization, apply lane equalization settings at both transmitter and receiver which results in an increase in the PCIe signal strength. While at it, modify the pcie-tegra194 driver to make use of the common GEN3_EQ_CONTROL_OFF definitions in pcie-designware.h. Link: https://lore.kernel.org/linux-pci/20240911-pci-qcom-gen4-stability-v7-3-743f5c1fd027@linaro.org Tested-by: Johan Hovold Signed-off-by: Shashank Babu Chinta Venkata [mani: dropped the code refactoring and minor changes] Signed-off-by: Manivannan Sadhasivam [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński Reviewed-by: Johan Hovold Reviewed-by: Manivannan Sadhasivam --- drivers/pci/controller/dwc/pcie-qcom-ep.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/pci/controller/dwc/pcie-qcom-ep.c') diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c index 3c1b695638f3..310d52393392 100644 --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c @@ -25,6 +25,7 @@ #include "../../pci.h" #include "pcie-designware.h" +#include "pcie-qcom-common.h" /* PARF registers */ #define PARF_SYS_CTRL 0x00 @@ -486,6 +487,9 @@ static int qcom_pcie_perst_deassert(struct dw_pcie *pci) goto err_disable_resources; } + if (pcie_link_speed[pci->max_link_speed] == PCIE_SPEED_16_0GT) + qcom_pcie_common_set_16gt_equalization(pci); + /* * The physical address of the MMIO region which is exposed as the BAR * should be written to MHI BASE registers. -- cgit v1.2.3-70-g09d2