Reviewed-by: Gilad Broner <gbro...@codeaurora.org>

> DME commands such as Hibern8 enter/exit and gear switch generate 2
> completion interrupts, one for confirmation that command is received
> by local UniPro and 2nd one is the final confirmation after communication
> with remote UniPro. Currently both of these completions are registered
> as interrupt events which is not quite necessary and instead we can
> just wait for the interrupt of 2nd completion, this should reduce
> the number of interrupts and could reduce the unnecessary CPU wakeups
> to handle extra interrupts.
>
> Signed-off-by: Subhash Jadavani <subha...@codeaurora.org>
> Signed-off-by: Yaniv Gardi <yga...@codeaurora.org>
>
> ---
>  drivers/scsi/ufs/ufshcd.c | 41 +++++++++++++++++++++++++++--------------
>  1 file changed, 27 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 889a7be..24a879d 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -987,13 +987,15 @@ ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct
> uic_command *uic_cmd)
>   * __ufshcd_send_uic_cmd - Send UIC commands and retrieve the result
>   * @hba: per adapter instance
>   * @uic_cmd: UIC command
> + * @completion: initialize the completion only if this is set to true
>   *
>   * Identical to ufshcd_send_uic_cmd() expect mutex. Must be called
>   * with mutex held and host_lock locked.
>   * Returns 0 only if success.
>   */
>  static int
> -__ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
> +__ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd,
> +                   bool completion)
>  {
>       if (!ufshcd_ready_for_uic_cmd(hba)) {
>               dev_err(hba->dev,
> @@ -1001,7 +1003,8 @@ __ufshcd_send_uic_cmd(struct ufs_hba *hba, struct
> uic_command *uic_cmd)
>               return -EIO;
>       }
>
> -     init_completion(&uic_cmd->done);
> +     if (completion)
> +             init_completion(&uic_cmd->done);
>
>       ufshcd_dispatch_uic_cmd(hba, uic_cmd);
>
> @@ -1026,7 +1029,7 @@ ufshcd_send_uic_cmd(struct ufs_hba *hba, struct
> uic_command *uic_cmd)
>       ufshcd_add_delay_before_dme_cmd(hba);
>
>       spin_lock_irqsave(hba->host->host_lock, flags);
> -     ret = __ufshcd_send_uic_cmd(hba, uic_cmd);
> +     ret = __ufshcd_send_uic_cmd(hba, uic_cmd, true);
>       spin_unlock_irqrestore(hba->host->host_lock, flags);
>       if (!ret)
>               ret = ufshcd_wait_for_uic_cmd(hba, uic_cmd);
> @@ -2347,6 +2350,7 @@ static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba,
> struct uic_command *cmd)
>       unsigned long flags;
>       u8 status;
>       int ret;
> +     bool reenable_intr = false;
>
>       mutex_lock(&hba->uic_cmd_mutex);
>       init_completion(&uic_async_done);
> @@ -2354,15 +2358,17 @@ static int ufshcd_uic_pwr_ctrl(struct ufs_hba
> *hba, struct uic_command *cmd)
>
>       spin_lock_irqsave(hba->host->host_lock, flags);
>       hba->uic_async_done = &uic_async_done;
> -     ret = __ufshcd_send_uic_cmd(hba, cmd);
> -     spin_unlock_irqrestore(hba->host->host_lock, flags);
> -     if (ret) {
> -             dev_err(hba->dev,
> -                     "pwr ctrl cmd 0x%x with mode 0x%x uic error %d\n",
> -                     cmd->command, cmd->argument3, ret);
> -             goto out;
> +     if (ufshcd_readl(hba, REG_INTERRUPT_ENABLE) & UIC_COMMAND_COMPL) {
> +             ufshcd_disable_intr(hba, UIC_COMMAND_COMPL);
> +             /*
> +              * Make sure UIC command completion interrupt is disabled before
> +              * issuing UIC command.
> +              */
> +             wmb();
> +             reenable_intr = true;
>       }
> -     ret = ufshcd_wait_for_uic_cmd(hba, cmd);
> +     ret = __ufshcd_send_uic_cmd(hba, cmd, false);
> +     spin_unlock_irqrestore(hba->host->host_lock, flags);
>       if (ret) {
>               dev_err(hba->dev,
>                       "pwr ctrl cmd 0x%x with mode 0x%x uic error %d\n",
> @@ -2388,7 +2394,10 @@ static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba,
> struct uic_command *cmd)
>       }
>  out:
>       spin_lock_irqsave(hba->host->host_lock, flags);
> +     hba->active_uic_cmd = NULL;
>       hba->uic_async_done = NULL;
> +     if (reenable_intr)
> +             ufshcd_enable_intr(hba, UIC_COMMAND_COMPL);
>       spin_unlock_irqrestore(hba->host->host_lock, flags);
>       mutex_unlock(&hba->uic_cmd_mutex);
>
> @@ -3813,16 +3822,20 @@ static void ufshcd_sl_intr(struct ufs_hba *hba,
> u32 intr_status)
>   */
>  static irqreturn_t ufshcd_intr(int irq, void *__hba)
>  {
> -     u32 intr_status;
> +     u32 intr_status, enabled_intr_status;
>       irqreturn_t retval = IRQ_NONE;
>       struct ufs_hba *hba = __hba;
>
>       spin_lock(hba->host->host_lock);
>       intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
> +     enabled_intr_status =
> +             intr_status & ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
>
> -     if (intr_status) {
> +     if (intr_status)
>               ufshcd_writel(hba, intr_status, REG_INTERRUPT_STATUS);
> -             ufshcd_sl_intr(hba, intr_status);
> +
> +     if (enabled_intr_status) {
> +             ufshcd_sl_intr(hba, enabled_intr_status);
>               retval = IRQ_HANDLED;
>       }
>       spin_unlock(hba->host->host_lock);
> --
> 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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