Hi, all
Could any one help review this patch set for me?
Thanks in advance.
δΊ 2013/9/24 16:12, Haijun Zhang ει:
> At 50 Mhz SD_CLK period,
> the max timeout value = 2^27 * SD_CLK period ~= 2.69 sec.
>
> If max_discard_to was not designed, for mmc card preferred erase
> size should be used, for sd card just return UINT_MAX. Also add
> limit for data transfer, Use max_discard_to as max data timeout value
> to avoid timeout error in case data timeout was larger than
> 2.69 sec.
>
> For some crappy cards, the timeout value calculate from card was
> larger than UINT_MAX, in this case the timeout value write into
> register was not expected.
>
> This patch can reduce I/O error due to large timeout value for
> erase(CMD38) and write(CMD25) for some crappy cards.
>
> Signed-off-by: Haijun Zhang <haijun.zh...@freescale.com>
> ---
> drivers/mmc/core/core.c | 45 ++++++++++++++++++++++++++++++---------------
> 1 file changed, 30 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index bf18b6b..b429baa 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -757,6 +757,7 @@ EXPORT_SYMBOL(mmc_read_bkops_status);
> */
> void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card)
> {
> + struct mmc_host *host = card->host;
> unsigned int mult;
>
> /*
> @@ -780,7 +781,12 @@ void mmc_set_data_timeout(struct mmc_data *data, const
> struct mmc_card *card)
> if (data->flags & MMC_DATA_WRITE)
> mult <<= card->csd.r2w_factor;
>
> - data->timeout_ns = card->csd.tacc_ns * mult;
> + /* Avoid over flow for some crappy cards. */
> + if ((UINT_MAX / mult) < card->csd.tacc_ns)
> + data->timeout_ns = UINT_MAX;
> + else
> + data->timeout_ns = card->csd.tacc_ns * mult;
> +
> data->timeout_clks = card->csd.tacc_clks * mult;
>
> /*
> @@ -842,6 +848,11 @@ void mmc_set_data_timeout(struct mmc_data *data, const
> struct mmc_card *card)
> data->timeout_ns = 100000000; /* 100ms */
> }
> }
> +
> + if (host->max_discard_to &&
> + (host->max_discard_to <
> + (data->timeout_ns / 1000000)))
> + data->timeout_ns = host->max_discard_to * 1000000;
> }
> EXPORT_SYMBOL(mmc_set_data_timeout);
>
> @@ -1816,11 +1827,14 @@ static unsigned int mmc_mmc_erase_timeout(struct
> mmc_card *card,
> unsigned int timeout_clks = card->csd.tacc_clks * mult;
> unsigned int timeout_us;
>
> - /* Avoid overflow: e.g. tacc_ns=80000000 mult=1280 */
> - if (card->csd.tacc_ns < 1000000)
> - timeout_us = (card->csd.tacc_ns * mult) / 1000;
> - else
> + /*
> + * Avoid over flow for some crappy cards.
> + * e.g. tacc_ns=80000000 mult=1280
> + */
> + if ((UINT_MAX / mult) < card->csd.tacc_ns)
> timeout_us = (card->csd.tacc_ns / 1000) * mult;
> + else
> + timeout_us = (card->csd.tacc_ns * mult) / 1000;
>
> /*
> * ios.clock is only a target. The real clock rate might be
> @@ -2185,16 +2199,17 @@ unsigned int mmc_calc_max_discard(struct mmc_card
> *card)
> struct mmc_host *host = card->host;
> unsigned int max_discard, max_trim;
>
> - if (!host->max_discard_to)
> - return UINT_MAX;
> -
> - /*
> - * Without erase_group_def set, MMC erase timeout depends on clock
> - * frequence which can change. In that case, the best choice is
> - * just the preferred erase size.
> - */
> - if (mmc_card_mmc(card) && !(card->ext_csd.erase_group_def & 1))
> - return card->pref_erase;
> + if (!host->max_discard_to) {
> + /*
> + * Without erase_group_def set, MMC erase timeout depends
> + * on clock frequence which can change. In that case, the
> + * best choice is just the preferred erase size.
> + */
> + if (mmc_card_mmc(card) && !(card->ext_csd.erase_group_def & 1))
> + return card->pref_erase;
> + else
> + return UINT_MAX;
> + }
>
> max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
> if (mmc_can_trim(card)) {
--
Thanks & Regards
Haijun.
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