Re: [PATCH V3 08/21] phy: tegra: p2u: Set ENABLE_L2_EXIT_RATE_CHANGE in calibration

Vinod Koul
2022-10-28T11:42:33Z

On 14-10-22, 00:08, Vidya Sagar wrote:
> Set ENABLE_L2_EXIT_RATE_CHANGE register bit to request UPHY PLL rate change
> to Gen1 during initialization. This helps in the below surprise link down
> cases,
> - Surprise link down happens at Gen3/Gen4 link speed.
> - Surprise link down happens and external REFCLK is cut off, which causes
> UPHY PLL rate to deviate to an invalid rate.

This looks okay to me and I can go ahead and apply, PCI patches can come
thru PCI tree and whenever ready use .calibrate() ?

>
> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> ---
> V3:
> * Removed "Reported-by: kernel test robot <lkp@intel.com>" based on Bjorn's review comment
> * Reworded the commit message
>
> V2:
> * Addressed review comment from test bot and Vinod
>
> drivers/phy/tegra/phy-tegra194-p2u.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/phy/tegra/phy-tegra194-p2u.c b/drivers/phy/tegra/phy-tegra194-p2u.c
> index 1415ca71de38..633e6b747275 100644
> --- a/drivers/phy/tegra/phy-tegra194-p2u.c
> +++ b/drivers/phy/tegra/phy-tegra194-p2u.c
> @@ -15,6 +15,7 @@
> #include <linux/phy/phy.h>
>
> #define P2U_CONTROL_CMN 0x74
> +#define P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE BIT(13)
> #define P2U_CONTROL_CMN_SKP_SIZE_PROTECTION_EN BIT(20)
>
> #define P2U_PERIODIC_EQ_CTRL_GEN3 0xc0
> @@ -85,8 +86,21 @@ static int tegra_p2u_power_on(struct phy *x)
> return 0;
> }
>
> +static int tegra_p2u_calibrate(struct phy *x)
> +{
> + struct tegra_p2u *phy = phy_get_drvdata(x);
> + u32 val;
> +
> + val = p2u_readl(phy, P2U_CONTROL_CMN);
> + val |= P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE;
> + p2u_writel(phy, val, P2U_CONTROL_CMN);
> +
> + return 0;
> +}
> +
> static const struct phy_ops ops = {
> .power_on = tegra_p2u_power_on,
> + .calibrate = tegra_p2u_calibrate,
> .owner = THIS_MODULE,
> };
>
> --
> 2.17.1

--
~Vinod