Re: [PATCH] mmc: dw-mmc: retry to send when inform ciu

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On 13 July 2012 09:28, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote:
> As DesignWare spec, when inform ciu, waiting for clearing start_bit
> or HLE is set. In case of HLE, repeat the command.
>
> Before the patch, repeat the below message.
> mmc_host mmc0: Timeout sending command (cmd 0x202000 arg 0x0 status 0x80202000)
> If this message is produced, repeat the send command during 10 times.
I dont understand what the above message. its not clear. can you
please explain it
>
> Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
>  drivers/mmc/host/dw_mmc.c |   39 +++++++++++++++++++++++++++++++--------
>  1 files changed, 31 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 72dc3cd..bec1a67 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -603,7 +603,7 @@ static void dw_mci_submit_data(struct dw_mci *host, struct mmc_data *data)
>         }
>  }
>
> -static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
> +static int mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
>  {
>         struct dw_mci *host = slot->host;
>         unsigned long timeout = jiffies + msecs_to_jiffies(500);
> @@ -616,11 +616,37 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
>         while (time_before(jiffies, timeout)) {
>                 cmd_status = mci_readl(host, CMD);
>                 if (!(cmd_status & SDMMC_CMD_START))
> -                       return;
> +                       return 0;
>         }
>         dev_err(&slot->mmc->class_dev,
>                 "Timeout sending command (cmd %#x arg %#x status %#x)\n",
>                 cmd, arg, cmd_status);
> +
> +       return -ETIMEDOUT;
> +}
> +
> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
> +{
> +       struct dw_mci *host = slot->host;
> +       unsigned long retry = 10;
> +       int ret;
> +       u32 ctrl;
> +
> +       while (1) {
> +               ret = mci_send_cmd(slot,
> +                    SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> +               if (!ret)
> +                       break;
the returned error type is timeout. Is it not necessary to read and
check the HLE bit here before resending.
> +               ctrl = mci_readl(host, CTRL);
> +               ctrl |= SDMMC_CTRL_RESET;
> +               mci_writel(host, CTRL, ctrl);
> +
> +               if (retry-- == 0) {
> +                       dev_err(&slot->mmc->class_dev,"Timeout inform CIU\n");
> +                       break;
> +               } else
> +                       dev_info(&slot->mmc->class_dev,"Retry send command\n");
> +       }
>  }
>
>  static void dw_mci_setup_bus(struct dw_mci_slot *slot)
> @@ -649,23 +675,20 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>                 mci_writel(host, CLKSRC, 0);
>
>                 /* inform CIU */
> -               mci_send_cmd(slot,
> -                            SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> +               dw_mci_inform_ciu(slot);
>
>                 /* set clock to desired speed */
>                 mci_writel(host, CLKDIV, div);
>
>                 /* inform CIU */
> -               mci_send_cmd(slot,
> -                            SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> +               dw_mci_inform_ciu(slot);
>
>                 /* enable clock */
>                 mci_writel(host, CLKENA, ((SDMMC_CLKEN_ENABLE |
>                            SDMMC_CLKEN_LOW_PWR) << slot->id));
>
>                 /* inform CIU */
> -               mci_send_cmd(slot,
> -                            SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> +               dw_mci_inform_ciu(slot);
>
>                 host->current_speed = slot->clock;
>         }
> --
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