On 19 May 2016 at 10:47, Chaotian Jing <chaotian.jing@xxxxxxxxxxxx> wrote:
> Per JEDEC spec, it is not recommended to use CMD13 to get card status
> after speed mode switch. below are two reason about this:
> 1. CMD13 cannot be guaranteed due to the asynchronous operation.
> Therefore it is not recommended to use CMD13 to check busy completion
> of the timing change indication.
> 2. After switch to HS200, CMD13 will get response of 0x800, and even the
> busy signal gets de-asserted, the response of CMD13 is aslo 0x800.
>
> Signed-off-by: Chaotian Jing <chaotian.jing@xxxxxxxxxxxx>
Thanks, applied for next! (With a minor change, see below)
[...]
>
> /* Switch HS to HS200 */
> val = EXT_CSD_TIMING_HS200 |
> card->drive_strength << EXT_CSD_DRV_STR_SHIFT;
> err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING,
> val, card->ext_csd.generic_cmd6_time, true,
> - send_status, true);
> + false, true);
To keep consistency with other calls to __mmc_switch(), I change these lines to:
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING,
val, card->ext_csd.generic_cmd6_time,
true, false, true);
> if (err)
> goto out_err;
>
> mmc_set_timing(host, MMC_TIMING_MMC_HS200);
>
> - if (!send_status) {
> - err = mmc_switch_status(card);
> - if (err)
> - goto out_err;
> - }
> + err = mmc_switch_status(card);
> + if (err)
> + goto out_err;
>
> mmc_set_bus_speed(card);
>
> @@ -1243,7 +1227,6 @@ static void mmc_select_driver_type(struct mmc_card *card)
> static int mmc_select_hs200(struct mmc_card *card)
> {
> struct mmc_host *host = card->host;
> - bool send_status = true;
> unsigned int old_timing;
> int err = -EINVAL;
> u8 val;
> @@ -1260,9 +1243,6 @@ static int mmc_select_hs200(struct mmc_card *card)
>
> mmc_select_driver_type(card);
>
> - if (host->caps & MMC_CAP_WAIT_WHILE_BUSY)
> - send_status = false;
> -
> /*
> * Set the bus width(4 or 8) with host's support and
> * switch to HS200 mode if bus width is set successfully.
> @@ -1274,20 +1254,18 @@ static int mmc_select_hs200(struct mmc_card *card)
> err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> EXT_CSD_HS_TIMING, val,
> card->ext_csd.generic_cmd6_time,
> - true, send_status, true);
> + true, false, true);
[...]
Kind regards
Uffe
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