Re: [PATCH v1 1/2] ufs: core: Configure only active lanes during link

[Shawn Lin <shawn.lin@rock-chips.com>]

Hi Palash

在 2026/03/11 星期三 14:09, palash.kambar@oss.qualcomm.com 写道:
> From: Palash Kambar <palash.kambar@oss.qualcomm.com>
> 
> The number of active lanes detected during UFS link startup can be

connected lanes(which is used in the code blow) or active lanes? There
are different primitives in UniPro context.

> 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.
> 

It sounds vague, how it causes failures, could you quote some clue from
spec?

> Hence, add check to identify only the lanes that were successfully
> discovered during link startup, to warn on power mode change errors
> caused by mismatched lane counts.
> 
> Signed-off-by: Palash Kambar <palash.kambar@oss.qualcomm.com>
> ---
>   drivers/ufs/core/ufshcd.c | 39 +++++++++++++++++++++++++++++++++++++++
>   1 file changed, 39 insertions(+)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 31950fc51a4c..c956fab32932 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -5035,6 +5035,42 @@ void ufshcd_update_evt_hist(struct ufs_hba *hba, u32 id, u32 val)
>   }
>   EXPORT_SYMBOL_GPL(ufshcd_update_evt_hist);
>   
> +static int ufshcd_get_connected_tx_lanes(struct ufs_hba *hba, u32 *tx_lanes)
> +{
> +	return ufshcd_dme_get(hba,
> +			      UIC_ARG_MIB(PA_CONNECTEDTXDATALANES), tx_lanes);
> +}
> +
> +static int ufshcd_get_connected_rx_lanes(struct ufs_hba *hba, u32 *rx_lanes)
> +{
> +	return ufshcd_dme_get(hba,
> +			      UIC_ARG_MIB(PA_CONNECTEDRXDATALANES), rx_lanes);
> +}
> +
> +static void ufshcd_validate_link_params(struct ufs_hba *hba)
> +{
> +	int val = 0;
> +
> +	if (ufshcd_get_connected_tx_lanes(hba, &val))
> +		return;
> +
> +	if (val != hba->lanes_per_direction) {
> +		dev_err(hba->dev, "Tx lane mismatch [config,reported] [%d,%d]\n",
> +			hba->lanes_per_direction, val);
> +		return;
> +	}
> +
> +	val = 0;
> +
> +	if (ufshcd_get_connected_rx_lanes(hba, &val))
> +		return;
> +
> +	if (val != hba->lanes_per_direction) {
> +		dev_err(hba->dev, "Rx lane mismatch [config,reported] [%d,%d]\n",
> +			hba->lanes_per_direction, val);
> +	}
> +}
> +
>   /**
>    * ufshcd_link_startup - Initialize unipro link startup
>    * @hba: per adapter instance
> @@ -5108,6 +5144,9 @@ static int ufshcd_link_startup(struct ufs_hba *hba)
>   			goto out;
>   	}
>   
> +	/* Check successfully detected lanes */
> +	ufshcd_validate_link_params(hba);
> +
>   	/* Include any host controller configuration via UIC commands */
>   	ret = ufshcd_vops_link_startup_notify(hba, POST_CHANGE);
>   	if (ret)
>