Re: [PATCH 1/1] scsi: ufs: Generalize UFS Interconnect Layer (UIC)command support

From: Santosh Y
Date: Thu May 02 2013 - 03:20:28 EST


> -static inline void
> -ufshcd_send_uic_command(struct ufs_hba *hba, struct uic_command *uic_cmnd)
> +static int ufshcd_send_uic_command(struct ufs_hba *hba,
> + struct uic_command *uic_cmnd, int retries)
> {
> + int err = 0;
> + unsigned long flags;
> +
> + if (unlikely(mutex_trylock(&hba->uic_cmd_mutex))) {
> + mutex_unlock(&hba->uic_cmd_mutex);
> + dev_err(hba->dev, "%s: called without prepare command\n",
> + __func__);
> + BUG();
> + }
> +
> +retry:
> + /* check if controller is ready to accept UIC commands */
> + if (!(readl(hba->mmio_base + REG_CONTROLLER_STATUS) &
> + UIC_COMMAND_READY)) {
> + dev_err(hba->dev, "Controller not ready to accept UIC commands\n");
> + err = -EIO;
> + goto out;
> + }
> +
> + init_completion(&uic_cmnd->completion);
> +
> + spin_lock_irqsave(hba->host->host_lock, flags);
> +
> + /* enable UIC related interrupts */
> + if (!(hba->int_enable_mask & UIC_COMMAND_COMPL)) {
> + hba->int_enable_mask |= UIC_COMMAND_COMPL;
> + ufshcd_int_config(hba, UFSHCD_INT_ENABLE);
> + }
> +

No need to check if the interrupt is already enabled, it can be
directly enabled.


> /* Write Args */
> writel(uic_cmnd->argument1,
> (hba->mmio_base + REG_UIC_COMMAND_ARG_1));
> @@ -415,6 +491,45 @@ ufshcd_send_uic_command(struct ufs_hba *hba, struct uic_command *uic_cmnd)
> /* Write UIC Cmd */
> writel((uic_cmnd->command & COMMAND_OPCODE_MASK),
> (hba->mmio_base + REG_UIC_COMMAND));
> +
> + /* flush to make sure h/w sees the write */
> + readl(hba->mmio_base + REG_UIC_COMMAND);
> +
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> +

mutex lock/unlock can be done in the send_uic_command, It will
simplify the process for the caller.

> + err = wait_for_completion_timeout(
> + &uic_cmnd->completion, UIC_COMMAND_TIMEOUT);
> + if (!err) {
> + err = -ETIMEDOUT;
> + } else if (uic_cmnd->argument2 & MASK_UIC_COMMAND_RESULT) {
> + /* something bad with h/w or arguments, try again */
> + if (--retries)
> + goto retry;
> +

--
~Santosh
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