[PATCH v9 2/4] PCI: brcmstb: Set reasonable value for internal bus timeout

From: Jim Quinlan
Date: Wed Apr 03 2024 - 17:39:42 EST


HW initializes an internal bus timeout register to a small value for
debugging convenience. Set this to something reasonable, i.e. in the
vicinity of 10 msec.

Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
---
drivers/pci/controller/pcie-brcmstb.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index f9dd6622fe10..e3480ca4cd57 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -664,6 +664,21 @@ static int brcm_pcie_enable_msi(struct brcm_pcie *pcie)
return 0;
}

+/*
+ * An internal HW bus timer value is set to a small value for debugging
+ * convenience. Set this to something reasonable, i.e. somewhere around
+ * 10ms.
+ */
+static void brcm_extend_internal_bus_timeout(struct brcm_pcie *pcie, u32 nsec)
+{
+ /* TIMEOUT register is two registers before RGR1_SW_INIT_1 */
+ const unsigned int REG_OFFSET = PCIE_RGR1_SW_INIT_1(pcie) - 8;
+ u32 timeout_us = nsec / 1000;
+
+ /* Each unit in timeout register is 1/216,000,000 seconds */
+ writel(216 * timeout_us, pcie->base + REG_OFFSET);
+}
+
/* The controller is capable of serving in both RC and EP roles */
static bool brcm_pcie_rc_mode(struct brcm_pcie *pcie)
{
@@ -1059,6 +1074,9 @@ static int brcm_pcie_start_link(struct brcm_pcie *pcie)
return -ENODEV;
}

+ /* Extend internal bus timeout to 8ms or so */
+ brcm_extend_internal_bus_timeout(pcie, SZ_8M);
+
if (pcie->gen)
brcm_pcie_set_gen(pcie, pcie->gen);

--
2.17.1

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