Re: [PATCH 2/3] scsi: ufs: Allow resetting the UFS device

[Stephen Boyd <swboyd@chromium.org>]

Quoting Bjorn Andersson (2019-06-04 00:20:00)
> @@ -6104,6 +6105,25 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
>         return err;
>  }
>  
> +/**
> + ufshcd_device_reset() - toggle the (optional) device reset line
> + * @hba: per-adapter instance
> + *
> + * Toggles the (optional) reset line to reset the attached device.
> + */
> +static void ufshcd_device_reset(struct ufs_hba *hba)
> +{
> +       /*
> +        * The USB device shall detect reset pulses of 1us, sleep for 10us to

This isn't usb though. Can we have a gpio reset driver and then
implement this in the reset framework instead? Or did that not work out
for some reason?

> +        * be on the safe side.
> +        */
> +       gpiod_set_value_cansleep(hba->device_reset, 1);
> +       usleep_range(10, 15);
> +
> +       gpiod_set_value_cansleep(hba->device_reset, 0);
> +       usleep_range(10, 15);
> +}
> +
>  /**
>   * ufshcd_host_reset_and_restore - reset and restore host controller
>   * @hba: per-adapter instance