PCI: qcom: Limit TLP size to 2K to work around hardware issue (b8f2a856) · Commits · 戴 / test

Limit TLP size to 2K to work around a hardware bug in the v0 version of PCIe IP. When using default TLP size of 4K, the internal buffer gets corrupted due to this hardware bug. This bug was originally noticed during ssh session between APQ8064-based board and PC. Network packets got corrupted randomly and terminated the ssh session due to this bug. Signed-off-by:

Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by:

Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/dwc/pcie-qcom.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -51,6 +51,12 @@
		#define PCIE20_ELBI_SYS_CTRL 0x04
		#define PCIE20_ELBI_SYS_CTRL_LT_ENABLE BIT(0)

		#define PCIE20_AXI_MSTR_RESP_COMP_CTRL0 0x818
		#define CFG_REMOTE_RD_REQ_BRIDGE_SIZE_2K 0x4
		#define CFG_REMOTE_RD_REQ_BRIDGE_SIZE_4K 0x5
		#define PCIE20_AXI_MSTR_RESP_COMP_CTRL1 0x81c
		#define CFG_BRIDGE_SB_INIT BIT(0)

		#define PCIE20_CAP 0x70

		#define PERST_DELAY_US 1000
		@@ -336,6 +342,13 @@ static int qcom_pcie_init_v0(struct qcom_pcie *pcie)
		/* wait for clock acquisition */
		usleep_range(1000, 1500);


		/* Set the Max TLP size to 2K, instead of using default of 4K */
		writel(CFG_REMOTE_RD_REQ_BRIDGE_SIZE_2K,
		pci->dbi_base + PCIE20_AXI_MSTR_RESP_COMP_CTRL0);
		writel(CFG_BRIDGE_SB_INIT,
		pci->dbi_base + PCIE20_AXI_MSTR_RESP_COMP_CTRL1);

		return 0;

		err_deassert_ahb:

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