Re: [PATCH 1/2] Support SD UHS for hikey-mainline-rebase

[Jaehoon Chung <jh80.chung@samsung.com>]

Hi,

Removed the unnecessary CC'd.

On 07/19/2016 04:51 PM, Jin Guojun wrote:
> From: j00226943 <j00226943@notesmail.huawei.com>

What is j00226943?

When you send the patch for dw_mmc controller, plz use the prefix "mmc: dw_mmc: ".

> 
> Two more changes:
> 
> Before we send cmd,we need to set CMD bit29 to
> 1 so that CMD and DATA sent to card through the HOLD Register,
> This is the explication in synosys host:To meet the relatively
> high Input Hold Time requirement for SDR12, SDR25, and other MMC
> speed modes, you should program bit[29]use_hold_Reg of the CMD
> register to 1'b1; the output data is then registered again in the
> cclk_in_drv domain by using the Hold Register as shown in Path B
> of Figure 10-8. However, for the higher speed modes of SDR104, SDR50
> and DDR50, you can meet the much smaller Input Hold Time requirement
> of 0.8ns by bypassing the Hold Register (Path A in Figure 10-8,
> programming CMD.use_hold_reg = 1'b0) and then adding delay elements
> on the output path as indicated
> 
> We have no tuning function in our drivers,so we must do the
> Function piling when we init UHS card.

Sorry..this patch is NACK.
SDMMC_CMD_USE_HOLD_REG is already used by default in dw_mmc.c
Which kernel version did you use?

> 
> Signed-off-by: Jin Guojun <kid.jin@hisilicon.com>
> ---
>  drivers/mmc/host/dw_mmc-k3.c | 6 ++++++
>  drivers/mmc/host/dw_mmc.c    | 2 ++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/mmc/host/dw_mmc-k3.c b/drivers/mmc/host/dw_mmc-k3.c
> index 63c2e2e..2cbfcc7 100644
> --- a/drivers/mmc/host/dw_mmc-k3.c
> +++ b/drivers/mmc/host/dw_mmc-k3.c
> @@ -125,10 +125,16 @@ static void dw_mci_hi6220_set_ios(struct dw_mci *host, struct mmc_ios *ios)
>  	host->bus_hz = clk_get_rate(host->biu_clk);
>  }
>  
> +static void dw_mci_hi6220_prepare_command(struct dw_mci *host, u32 *cmdr)
> +{
> +	*cmdr |= SDMMC_CMD_USE_HOLD_REG;
> +}
> +
>  static const struct dw_mci_drv_data hi6220_data = {
>  	.switch_voltage		= dw_mci_hi6220_switch_voltage,
>  	.set_ios		= dw_mci_hi6220_set_ios,
>  	.parse_dt		= dw_mci_hi6220_parse_dt,
> +	.prepare_command        = dw_mci_hi6220_prepare_command,
>  };

There is no "prepare_command" hooks.

Best Regards,
Jaehoon Chung

>  
>  static const struct of_device_id dw_mci_k3_match[] = {
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 9dd1bd3..047e116 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1564,6 +1564,8 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>  
>  	if (drv_data && drv_data->execute_tuning)
>  		err = drv_data->execute_tuning(slot, opcode);
> +	else
> +		err = 0;
>  	return err;
>  }
>  
>