Re: [PATCH V3 1/2] ufs: core: Configure only active lanes during link

[Manivannan Sadhasivam]

On Tue, Apr 14, 2026 at 03:01:34PM +0530, palash.kambar@xxxxxxxxxxxxxxxx wrote:
> From: Palash Kambar <palash.kambar@xxxxxxxxxxxxxxxx>
> 
> The number of connected lanes detected during UFS link startup can be
> fewer than the lanes specified in the device tree. The current driver
> logic attempts to configure all lanes defined in the device tree,
> regardless of their actual availability. This mismatch may cause
> failures during power mode changes.
> 
> Hence, Add a check during link startup to ensure that only the lanes
> actually discovered are considered valid. If a mismatch is detected,
> fail the initialization early, preventing the driver from entering
> an unsupported configuration that could cause power mode transition
> failures.
> 
> Signed-off-by: Palash Kambar <palash.kambar@xxxxxxxxxxxxxxxx>
> ---
>  drivers/ufs/core/ufshcd.c | 37 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 31950fc51a4c..754bf4df3016 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -5035,6 +5035,38 @@ void ufshcd_update_evt_hist(struct ufs_hba *hba, u32 id, u32 val)
>  }
>  EXPORT_SYMBOL_GPL(ufshcd_update_evt_hist);
>  
> +static int ufshcd_validate_link_params(struct ufs_hba *hba)
> +{
> +	int ret;
> +	int val;

ret, val

> +
> +	ret = ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDTXDATALANES),
> +			     &val);
> +	if (ret)
> +		goto out;
> +
> +	if (val != hba->lanes_per_direction) {
> +		dev_err(hba->dev, "Tx lane mismatch [config,reported] [%d,%d]\n",
> +			hba->lanes_per_direction, val);
> +		ret = -ENOLINK;
> +		goto out;
> +	}
> +
> +	ret = ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDRXDATALANES),
> +			     &val);
> +	if (ret)
> +		goto out;
> +
> +	if (val != hba->lanes_per_direction) {
> +		dev_err(hba->dev, "Rx lane mismatch [config,reported] [%d,%d]\n",
> +			hba->lanes_per_direction, val);
> +		ret = -ENOLINK;

		goto out;

> +	}
> +

return 0;

> +out:
> +	return ret;
> +}
> +
>  /**
>   * ufshcd_link_startup - Initialize unipro link startup
>   * @hba: per adapter instance
> @@ -5108,6 +5140,11 @@ static int ufshcd_link_startup(struct ufs_hba *hba)
>  			goto out;
>  	}
>  
> +	/* Check successfully detected lanes */

Drop the comment.

- Mani

-- 
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