Re: [PATCH v2] ufs: introduce UFSHCD_QUIRK_BROKEN_REQ_LIST_CLR quirk

[Subhash Jadavani <subhashj@codeaurora.org>]

On 2016-11-15 02:52, Kiwoong Kim wrote:
> Some UFS host controllers may clear a transfer request slot
> by setting an associated bit in UTRLCLR/UTMRLCLR to 1, not 0.
> That's opposite to what UFS spec describes.
> 
> v2: modify the commit message, remove unrelated changes

As Martin mentioned in other email, please separate this version history 
from commit text with line having "----" before the start of version 
history.
Rest all looks good but i will wait for updated patch fixing above 
before giving Reviewed-By.

> 
> Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
> ---
>  drivers/scsi/ufs/ufshcd.c | 28 ++++++++++++++++++++++++++--
>  drivers/scsi/ufs/ufshcd.h |  7 +++++++
>  2 files changed, 33 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index d6e3112..c9cf011 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -392,7 +392,31 @@ static inline void ufshcd_put_tm_slot(struct
> ufs_hba *hba, int slot)
>   */
>  static inline void ufshcd_utrl_clear(struct ufs_hba *hba, u32 pos)
>  {
> -	ufshcd_writel(hba, ~(1 << pos), REG_UTP_TRANSFER_REQ_LIST_CLEAR);
> +	u32 clear;
> +
> +	if (hba->quirks & UFSHCD_QUIRK_BROKEN_REQ_LIST_CLR)
> +		clear = (1 << pos);
> +	else
> +		clear = ~(1 << pos);
> +
> +	ufshcd_writel(hba, clear, REG_UTP_TRANSFER_REQ_LIST_CLEAR);
> +}
> +
> +/**
> + * ufshcd_utmrl_clear - Clear a bit in UTRMLCLR register
> + * @hba: per adapter instance
> + * @pos: position of the bit to be cleared
> + */
> +static inline void ufshcd_utmrl_clear(struct ufs_hba *hba, u32 pos)
> +{
> +	u32 clear;
> +
> +	if (hba->quirks & UFSHCD_QUIRK_BROKEN_REQ_LIST_CLR)
> +		clear = (1 << pos);
> +	else
> +		clear = ~(1 << pos);
> +
> +	ufshcd_writel(hba, clear, REG_UTP_TASK_REQ_LIST_CLEAR);
>  }
> 
>  /**
> @@ -4312,7 +4336,7 @@ static int ufshcd_clear_tm_cmd(struct ufs_hba
> *hba, int tag)
>  		goto out;
> 
>  	spin_lock_irqsave(hba->host->host_lock, flags);
> -	ufshcd_writel(hba, ~(1 << tag), REG_UTP_TASK_REQ_LIST_CLEAR);
> +	ufshcd_utmrl_clear(hba, tag);
>  	spin_unlock_irqrestore(hba->host->host_lock, flags);
> 
>  	/* poll for max. 1 sec to clear door bell register by h/w */
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 7d9ff22..9838598 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -491,6 +491,13 @@ struct ufs_hba {
>  	 */
>  	#define UFSHCD_QUIRK_PRDT_BYTE_GRAN			UFS_BIT(7)
> 
> +	/*
> +	 * This quirk needs to be enabled if the host contoller has to set
> +	 * the bit corresponding the slot to be cleared to 1, not 0 as
> +	 * described in UFS spec.
> +	 */
> +	#define UFSHCD_QUIRK_BROKEN_REQ_LIST_CLR                UFS_BIT(8)
> +
>  	unsigned int quirks;	/* Deviations from standard UFSHCI spec. */
> 
>  	/* Device deviations from standard UFS device spec. */

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