* [PATCH] PCI: mediatek-gen3: Print LTSSM state when PCIe link down
@ 2022-03-24 7:25 Jianjun Wang
2022-03-28 14:39 ` AngeloGioacchino Del Regno
0 siblings, 1 reply; 3+ messages in thread
From: Jianjun Wang @ 2022-03-24 7:25 UTC (permalink / raw)
To: Ryder Lee, Lorenzo Pieralisi, Bjorn Helgaas
Cc: Jianjun Wang, Rob Herring, Krzysztof Wilczyński,
Matthias Brugger, linux-pci, linux-mediatek, linux-kernel,
linux-arm-kernel, jieyy.yang, chuanjia.liu, qizhong.cheng,
jian.yang
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
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^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] PCI: mediatek-gen3: Print LTSSM state when PCIe link down
2022-03-24 7:25 [PATCH] PCI: mediatek-gen3: Print LTSSM state when PCIe link down Jianjun Wang
@ 2022-03-28 14:39 ` AngeloGioacchino Del Regno
2022-03-29 2:00 ` Jianjun Wang
0 siblings, 1 reply; 3+ messages in thread
From: AngeloGioacchino Del Regno @ 2022-03-28 14:39 UTC (permalink / raw)
To: Jianjun Wang, Ryder Lee, Lorenzo Pieralisi, Bjorn Helgaas
Cc: Rob Herring, Krzysztof Wilczyński, Matthias Brugger,
linux-pci, linux-mediatek, linux-kernel, linux-arm-kernel,
jieyy.yang, chuanjia.liu, qizhong.cheng, jian.yang
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
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] PCI: mediatek-gen3: Print LTSSM state when PCIe link down
2022-03-28 14:39 ` AngeloGioacchino Del Regno
@ 2022-03-29 2:00 ` Jianjun Wang
0 siblings, 0 replies; 3+ messages in thread
From: Jianjun Wang @ 2022-03-29 2:00 UTC (permalink / raw)
To: AngeloGioacchino Del Regno, Ryder Lee, Lorenzo Pieralisi,
Bjorn Helgaas
Cc: Rob Herring, Krzysztof Wilczyński, Matthias Brugger,
linux-pci, linux-mediatek, linux-kernel, linux-arm-kernel,
jieyy.yang, chuanjia.liu, qizhong.cheng, jian.yang
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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2022-03-24 7:25 [PATCH] PCI: mediatek-gen3: Print LTSSM state when PCIe link down Jianjun Wang
2022-03-28 14:39 ` AngeloGioacchino Del Regno
2022-03-29 2:00 ` Jianjun Wang
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