2015-09-02 19:13 GMT+09:00 Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>:
> Performing several writes to UFS host controller registers has
> no gurrantee of ordering, so we must make sure register writes
> to setup request list base address etc. are performed before the
> run/stop register is enabled.
> In addition, when setting up a task request, we must make sure
> the updating of descriptors takes places before ringing the
> doorbell, similarly to setting up a transfer request.
>
> Signed-off-by: Gilad Broner <gbroner@xxxxxxxxxxxxxx>
> Signed-off-by: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>
>
> ---
> drivers/scsi/ufs/ufshcd.c | 21 +++++++++++++++------
> 1 file changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index fc2a52d..298511a 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -401,11 +401,9 @@ static inline int ufshcd_get_lists_status(u32 reg)
> * 1 UTRLRDY
> * 2 UTMRLRDY
> * 3 UCRDY
> - * 4 HEI
> - * 5 DEI
> - * 6-7 reserved
> + * 4-7 reserved
> */
> - return (((reg) & (0xFF)) >> 1) ^ (0x07);
> + return ((reg & 0xFF) >> 1) ^ 0x07;
> }
>
> /**
> @@ -2726,7 +2724,7 @@ out:
> * To bring UFS host controller to operational state,
> * 1. Enable required interrupts
> * 2. Configure interrupt aggregation
> - * 3. Program UTRL and UTMRL base addres
> + * 3. Program UTRL and UTMRL base address
> * 4. Configure run-stop-registers
> *
> * Returns 0 on success, non-zero value on failure
> @@ -2756,8 +2754,13 @@ static int ufshcd_make_hba_operational(struct ufs_hba *hba)
> REG_UTP_TASK_REQ_LIST_BASE_H);
>
> /*
> + * Make sure base address and interrupt setup are updated before
> + * enabling the run/stop registers below.
> + */
> + wmb();
> +
> + /*
> * UCRDY, UTMRLDY and UTRLRDY bits must be 1
> - * DEI, HEI bits must be 0
> */
> reg = ufshcd_readl(hba, REG_CONTROLLER_STATUS);
> if (!(ufshcd_get_lists_status(reg))) {
> @@ -3920,7 +3923,13 @@ static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int lun_id, int task_id,
>
> /* send command to the controller */
> __set_bit(free_slot, &hba->outstanding_tasks);
> +
> + /* Make sure descriptors are ready before ringing the task doorbell */
> + wmb();
> +
> ufshcd_writel(hba, 1 << free_slot, REG_UTP_TASK_REQ_DOOR_BELL);
> + /* Make sure that doorbell is committed immediately */
> + wmb();
Is this wmb() after ringing tm doorbell is needed?
>
> spin_unlock_irqrestore(host->host_lock, flags);
>
> --
> 1.8.5.2
>
> --
> QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
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