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authorJianjun Wang <jianjun.wang@mediatek.com>2022-03-29 06:07:15 +0300
committerBjorn Helgaas <bhelgaas@google.com>2022-06-15 22:58:22 +0300
commit28fc842e14729df641326b4deb3aa275ca648fce (patch)
tree768017893d1bffb4b36adc90e1daeef801a4f57d
parentbf038503d5fe90189743124233fe7aeb0984e961 (diff)
downloadlinux-28fc842e14729df641326b4deb3aa275ca648fce.tar.xz
PCI: mediatek-gen3: Print LTSSM state when PCIe link down
Print current LTSSM state when PCIe link down instead of the register value to make it easier to get the link status. Link: https://lore.kernel.org/r/20220329030715.7975-1-jianjun.wang@mediatek.com Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
-rw-r--r--drivers/pci/controller/pcie-mediatek-gen3.c41
1 files changed, 40 insertions, 1 deletions
diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index a02c466a597c..6577c7162507 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -153,6 +153,37 @@ struct mtk_gen3_pcie {
DECLARE_BITMAP(msi_irq_in_use, PCIE_MSI_IRQS_NUM);
};
+/* LTSSM state in PCIE_LTSSM_STATUS_REG bit[28:24] */
+static const char *const ltssm_str[] = {
+ "detect.quiet", /* 0x00 */
+ "detect.active", /* 0x01 */
+ "polling.active", /* 0x02 */
+ "polling.compliance", /* 0x03 */
+ "polling.configuration", /* 0x04 */
+ "config.linkwidthstart", /* 0x05 */
+ "config.linkwidthaccept", /* 0x06 */
+ "config.lanenumwait", /* 0x07 */
+ "config.lanenumaccept", /* 0x08 */
+ "config.complete", /* 0x09 */
+ "config.idle", /* 0x0A */
+ "recovery.receiverlock", /* 0x0B */
+ "recovery.equalization", /* 0x0C */
+ "recovery.speed", /* 0x0D */
+ "recovery.receiverconfig", /* 0x0E */
+ "recovery.idle", /* 0x0F */
+ "L0", /* 0x10 */
+ "L0s", /* 0x11 */
+ "L1.entry", /* 0x12 */
+ "L1.idle", /* 0x13 */
+ "L2.idle", /* 0x14 */
+ "L2.transmitwake", /* 0x15 */
+ "disable", /* 0x16 */
+ "loopback.entry", /* 0x17 */
+ "loopback.active", /* 0x18 */
+ "loopback.exit", /* 0x19 */
+ "hotreset", /* 0x1A */
+};
+
/**
* mtk_pcie_config_tlp_header() - Configure a configuration TLP header
* @bus: PCI bus to query
@@ -327,8 +358,16 @@ static int mtk_pcie_startup_port(struct mtk_gen3_pcie *pcie)
!!(val & PCIE_PORT_LINKUP), 20,
PCI_PM_D3COLD_WAIT * USEC_PER_MSEC);
if (err) {
+ const char *ltssm_state;
+ int ltssm_index;
+
val = readl_relaxed(pcie->base + PCIE_LTSSM_STATUS_REG);
- dev_err(pcie->dev, "PCIe link down, ltssm reg val: %#x\n", val);
+ ltssm_index = PCIE_LTSSM_STATE(val);
+ ltssm_state = ltssm_index >= ARRAY_SIZE(ltssm_str) ?
+ "Unknown state" : ltssm_str[ltssm_index];
+ dev_err(pcie->dev,
+ "PCIe link down, current LTSSM state: %s (%#x)\n",
+ ltssm_state, val);
return err;
}