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

Vidya Sagar
2022-10-28T11:50:18Z

Thanks for the review and yes please go ahead and apply.

Thanks,
Vidya Sagar

On 10/28/2022 5:12 PM, Vinod Koul wrote:
> External email: Use caution opening links or attachments
>
>
> 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
>