drivers/pci/controller/pcie-mediatek-gen3.c | 40 ++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-)
Print current LTSSM state when PCIe link down instead of the register
value, make it easier to get the link status.
Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
---
drivers/pci/controller/pcie-mediatek-gen3.c | 40 ++++++++++++++++++++-
1 file changed, 39 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index 7705d61fba4c..54663f025e27 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 +358,15 @@ 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\n",
+ ltssm_state);
return err;
}
--
2.18.0
Il 24/03/22 08:25, Jianjun Wang ha scritto: > Print current LTSSM state when PCIe link down instead of the register > value, make it easier to get the link status. > > Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com> Hello Jianjun, this patch is really helpful when comes to understand the source of an issue, so I agree with it - and thank you for that. Though, I think that you should still print the hex number along with the meaning of it, check below: > --- > drivers/pci/controller/pcie-mediatek-gen3.c | 40 ++++++++++++++++++++- > 1 file changed, 39 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c > index 7705d61fba4c..54663f025e27 100644 > --- a/drivers/pci/controller/pcie-mediatek-gen3.c > +++ b/drivers/pci/controller/pcie-mediatek-gen3.c ..snip.. > @@ -327,8 +358,15 @@ 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\n", There, I think that you should do: dev_err(pcie->dev, "PCIe link down, current LTSSM state: %s (%#x)\n", ltssm_state, val); this will be extremely useful in the "Unknown state" case. After fixing that, Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Regards, Angelo
On Mon, 2022-03-28 at 16:39 +0200, AngeloGioacchino Del Regno wrote: > Il 24/03/22 08:25, Jianjun Wang ha scritto: > > Print current LTSSM state when PCIe link down instead of the > > register > > value, make it easier to get the link status. > > > > Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com> > > Hello Jianjun, > this patch is really helpful when comes to understand the source of > an issue, > so I agree with it - and thank you for that. > > Though, I think that you should still print the hex number along with > the > meaning of it, check below: > > > --- > > drivers/pci/controller/pcie-mediatek-gen3.c | 40 > > ++++++++++++++++++++- > > 1 file changed, 39 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c > > b/drivers/pci/controller/pcie-mediatek-gen3.c > > index 7705d61fba4c..54663f025e27 100644 > > --- a/drivers/pci/controller/pcie-mediatek-gen3.c > > +++ b/drivers/pci/controller/pcie-mediatek-gen3.c > > ..snip.. > > > @@ -327,8 +358,15 @@ 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\n", > > There, I think that you should do: > > dev_err(pcie->dev, "PCIe link down, current LTSSM state: %s (%#x)\n", > ltssm_state, val); > > this will be extremely useful in the "Unknown state" case. > > After fixing that, > > Reviewed-by: AngeloGioacchino Del Regno < > angelogioacchino.delregno@collabora.com> Thanks! > > Regards, > Angelo
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