2021-10-15 13:00:30

by Jianjun Wang (王建军)

Subject: [PATCH v3] PCI: mediatek-gen3: Disable DVFSRC voltage request

When the DVFSRC (dynamic voltage and frequency scaling resource collector)
feature is not implemented, the PCIe hardware will assert a voltage request
signal when exit from the L1 PM Substates to request a specific Vcore
voltage, but cannot receive the voltage ready signal, which will cause
the link to fail to exit the L1 PM Substates.

Disable DVFSRC voltage request by default, we need to find a common way to
enable it in the future.

Fixes: d3bf75b579b9 ("PCI: mediatek-gen3: Add MediaTek Gen3 driver for MT8192")
Signed-off-by: Jianjun Wang <[email protected]>
Reviewed-by: Tzung-Bi Shih <[email protected]>
Tested-by: Qizhong Cheng <[email protected]>
---
drivers/pci/controller/pcie-mediatek-gen3.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index f3aeb8d4eaca..79fb12fca6a9 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -79,6 +79,9 @@
#define PCIE_ICMD_PM_REG 0x198
#define PCIE_TURN_OFF_LINK BIT(4)

+#define PCIE_MISC_CTRL_REG 0x348
+#define PCIE_DISABLE_DVFSRC_VLT_REQ BIT(1)
+
#define PCIE_TRANS_TABLE_BASE_REG 0x800
#define PCIE_ATR_SRC_ADDR_MSB_OFFSET 0x4
#define PCIE_ATR_TRSL_ADDR_LSB_OFFSET 0x8
@@ -297,6 +300,11 @@ static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
val &= ~PCIE_INTX_ENABLE;
writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);

+ /* Disable DVFSRC voltage request */
+ val = readl_relaxed(port->base + PCIE_MISC_CTRL_REG);
+ val |= PCIE_DISABLE_DVFSRC_VLT_REQ;
+ writel_relaxed(val, port->base + PCIE_MISC_CTRL_REG);
+
/* Assert all reset signals */
val = readl_relaxed(port->base + PCIE_RST_CTRL_REG);
val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB;
--
2.25.1

2021-11-09 14:32:53

by Jianjun Wang (王建军)

Subject: Re: [PATCH v3] PCI: mediatek-gen3: Disable DVFSRC voltage request

Hi Maintainers,

Just gentle ping for this patch, if there is anything I need to modify,
please kindly let me know.

Thanks.

On Fri, 2021-10-15 at 14:36 +0800, Jianjun Wang wrote:
> When the DVFSRC (dynamic voltage and frequency scaling resource
> collector)
> feature is not implemented, the PCIe hardware will assert a voltage
> request
> signal when exit from the L1 PM Substates to request a specific Vcore
> voltage, but cannot receive the voltage ready signal, which will
> cause
> the link to fail to exit the L1 PM Substates.
>
> Disable DVFSRC voltage request by default, we need to find a common
> way to
> enable it in the future.
>
> Fixes: d3bf75b579b9 ("PCI: mediatek-gen3: Add MediaTek Gen3 driver
> for MT8192")
> Signed-off-by: Jianjun Wang <[email protected]>
> Reviewed-by: Tzung-Bi Shih <[email protected]>
> Tested-by: Qizhong Cheng <[email protected]>
> ---
> drivers/pci/controller/pcie-mediatek-gen3.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c
> b/drivers/pci/controller/pcie-mediatek-gen3.c
> index f3aeb8d4eaca..79fb12fca6a9 100644
> --- a/drivers/pci/controller/pcie-mediatek-gen3.c
> +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> @@ -79,6 +79,9 @@
> #define PCIE_ICMD_PM_REG 0x198
> #define PCIE_TURN_OFF_LINK BIT(4)
>
> +#define PCIE_MISC_CTRL_REG 0x348
> +#define PCIE_DISABLE_DVFSRC_VLT_REQ BIT(1)
> +
> #define PCIE_TRANS_TABLE_BASE_REG 0x800
> #define PCIE_ATR_SRC_ADDR_MSB_OFFSET 0x4
> #define PCIE_ATR_TRSL_ADDR_LSB_OFFSET 0x8
> @@ -297,6 +300,11 @@ static int mtk_pcie_startup_port(struct
> mtk_pcie_port *port)
> val &= ~PCIE_INTX_ENABLE;
> writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);
>
> + /* Disable DVFSRC voltage request */
> + val = readl_relaxed(port->base + PCIE_MISC_CTRL_REG);
> + val |= PCIE_DISABLE_DVFSRC_VLT_REQ;
> + writel_relaxed(val, port->base + PCIE_MISC_CTRL_REG);
> +
> /* Assert all reset signals */
> val = readl_relaxed(port->base + PCIE_RST_CTRL_REG);
> val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
> PCIE_PE_RSTB;

2021-11-17 17:41:52

by Matthias Brugger

Subject: Re: [PATCH v3] PCI: mediatek-gen3: Disable DVFSRC voltage request

On 15/10/2021 08:36, Jianjun Wang wrote:
> When the DVFSRC (dynamic voltage and frequency scaling resource collector)
> feature is not implemented, the PCIe hardware will assert a voltage request
> signal when exit from the L1 PM Substates to request a specific Vcore
> voltage, but cannot receive the voltage ready signal, which will cause
> the link to fail to exit the L1 PM Substates.
>
> Disable DVFSRC voltage request by default, we need to find a common way to
> enable it in the future.
>
> Fixes: d3bf75b579b9 ("PCI: mediatek-gen3: Add MediaTek Gen3 driver for MT8192")
> Signed-off-by: Jianjun Wang <[email protected]>
> Reviewed-by: Tzung-Bi Shih <[email protected]>
> Tested-by: Qizhong Cheng <[email protected]>

Reviewed-by: Matthias Brugger <[email protected]>

> ---
> drivers/pci/controller/pcie-mediatek-gen3.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
> index f3aeb8d4eaca..79fb12fca6a9 100644
> --- a/drivers/pci/controller/pcie-mediatek-gen3.c
> +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> @@ -79,6 +79,9 @@
> #define PCIE_ICMD_PM_REG 0x198
> #define PCIE_TURN_OFF_LINK BIT(4)
>
> +#define PCIE_MISC_CTRL_REG 0x348
> +#define PCIE_DISABLE_DVFSRC_VLT_REQ BIT(1)
> +
> #define PCIE_TRANS_TABLE_BASE_REG 0x800
> #define PCIE_ATR_SRC_ADDR_MSB_OFFSET 0x4
> #define PCIE_ATR_TRSL_ADDR_LSB_OFFSET 0x8
> @@ -297,6 +300,11 @@ static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
> val &= ~PCIE_INTX_ENABLE;
> writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);
>
> + /* Disable DVFSRC voltage request */
> + val = readl_relaxed(port->base + PCIE_MISC_CTRL_REG);
> + val |= PCIE_DISABLE_DVFSRC_VLT_REQ;
> + writel_relaxed(val, port->base + PCIE_MISC_CTRL_REG);
> +
> /* Assert all reset signals */
> val = readl_relaxed(port->base + PCIE_RST_CTRL_REG);
> val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB;
>

2021-11-29 02:54:07

by Jianjun Wang (王建军)

Subject: Re: [PATCH v3] PCI: mediatek-gen3: Disable DVFSRC voltage request

Hi Maintainers,

Just gentle ping for this patch, is there anything I need to do to get
this patch merged?

Thanks.

On Tue, 2021-11-09 at 14:10 +0800, Jianjun Wang wrote:
>
> On Fri, 2021-10-15 at 14:36 +0800, Jianjun Wang wrote:
> > When the DVFSRC (dynamic voltage and frequency scaling resource
> > collector)
> > feature is not implemented, the PCIe hardware will assert a voltage
> > request
> > signal when exit from the L1 PM Substates to request a specific
> > Vcore
> > voltage, but cannot receive the voltage ready signal, which will
> > cause
> > the link to fail to exit the L1 PM Substates.
> >
> > Disable DVFSRC voltage request by default, we need to find a common
> > way to
> > enable it in the future.
> >
> > Fixes: d3bf75b579b9 ("PCI: mediatek-gen3: Add MediaTek Gen3 driver
> > for MT8192")
> > Signed-off-by: Jianjun Wang <[email protected]>
> > Reviewed-by: Tzung-Bi Shih <[email protected]>
> > Tested-by: Qizhong Cheng <[email protected]>
> > ---
> > drivers/pci/controller/pcie-mediatek-gen3.c | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c
> > b/drivers/pci/controller/pcie-mediatek-gen3.c
> > index f3aeb8d4eaca..79fb12fca6a9 100644
> > --- a/drivers/pci/controller/pcie-mediatek-gen3.c
> > +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> > @@ -79,6 +79,9 @@
> > #define PCIE_ICMD_PM_REG 0x198
> > #define PCIE_TURN_OFF_LINK BIT(4)
> >
> > +#define PCIE_MISC_CTRL_REG 0x348
> > +#define PCIE_DISABLE_DVFSRC_VLT_REQ BIT(1)
> > +
> > #define PCIE_TRANS_TABLE_BASE_REG 0x800
> > #define PCIE_ATR_SRC_ADDR_MSB_OFFSET 0x4
> > #define PCIE_ATR_TRSL_ADDR_LSB_OFFSET 0x8
> > @@ -297,6 +300,11 @@ static int mtk_pcie_startup_port(struct
> > mtk_pcie_port *port)
> > val &= ~PCIE_INTX_ENABLE;
> > writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);
> >
> > + /* Disable DVFSRC voltage request */
> > + val = readl_relaxed(port->base + PCIE_MISC_CTRL_REG);
> > + val |= PCIE_DISABLE_DVFSRC_VLT_REQ;
> > + writel_relaxed(val, port->base + PCIE_MISC_CTRL_REG);
> > +
> > /* Assert all reset signals */
> > val = readl_relaxed(port->base + PCIE_RST_CTRL_REG);
> > val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
> > PCIE_PE_RSTB;
>
> _______________________________________________
> Linux-mediatek mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-mediatek

2021-11-29 12:13:10

by Lorenzo Pieralisi

Subject: Re: [PATCH v3] PCI: mediatek-gen3: Disable DVFSRC voltage request

On Fri, 15 Oct 2021 14:36:02 +0800, Jianjun Wang wrote:
> When the DVFSRC (dynamic voltage and frequency scaling resource collector)
> feature is not implemented, the PCIe hardware will assert a voltage request
> signal when exit from the L1 PM Substates to request a specific Vcore
> voltage, but cannot receive the voltage ready signal, which will cause
> the link to fail to exit the L1 PM Substates.
>
> Disable DVFSRC voltage request by default, we need to find a common way to
> enable it in the future.
>
> [...]

Applied to pci/mediatek-gen3, thanks!

[1/1] PCI: mediatek-gen3: Disable DVFSRC voltage request
https://git.kernel.org/lpieralisi/pci/c/ab344fd43f

Thanks,
Lorenzo